Add total upstream count retrieval to UpstreamService

- Added transaction support in `add_upstream_target`, `remove_upstream`, `remove_upstream_target`, `update_upstream`, and `update_upstream_target` functions to ensure atomicity of operations.
- Updated the `NginxService` to include methods for validating and applying configurations using the agent service.
- Enhanced error handling in agent service interactions, returning appropriate internal server errors when agent communication fails.
- Introduced mock agent service for testing, allowing for simulation of agent interactions without actual network calls.
- Refactored tests to cover scenarios where agent operations fail, ensuring that internal server errors are returned as expected.

.github/actions/setup-rust/action.yml

@@ -22,7 +22,7 @@ runs:
         fetch-depth: 0
 
     - name: Cache cargo registry
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cargo/registry
         key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
@@ -30,7 +30,7 @@ runs:
           ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
 
     - name: Cache cargo index
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cargo/index
         key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
@@ -51,7 +51,7 @@ runs:
           ${{ runner.os }}-rustup-
 
     - name: Cache cargo build (target)
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: target
         key: ${{ runner.os }}-cargo-build-${{ hashFiles('**/Cargo.lock') }}

.github/workflows/test.yml

@@ -12,11 +12,8 @@ on:
 
 
 jobs:
-  # setup is now handled by a composite action used by downstream jobs to keep
-  # the workflow DRY. The composite action performs checkout, cache restore and
-  # toolchain setup.
 
-  test:
+  test-crates:
     needs: frontend-build
     runs-on: ubuntu-latest
     steps:
@@ -39,7 +36,7 @@ jobs:
       - name: Run tests
         run: cargo test --all-features
 
-  lint:
+  lint-crates:
     needs: frontend-build
     runs-on: ubuntu-latest
     steps:
@@ -67,6 +64,34 @@ jobs:
       - name: Check code formatting
         run: cargo fmt --all -- --check
 
+  lint-frontend:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - uses: pnpm/action-setup@v4
+        with:
+          version: 10
+          run_install: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: 'pnpm'
+          cache-dependency-path: pnpm-lock.yaml
+
+      - name: Install frontend dependencies
+        run: |
+          cd apps/frontend
+          pnpm install
+
+      - name: Run frontend linter
+        run: |
+          cd apps/frontend
+          pnpm lint
+
   test-frontend:
     runs-on: ubuntu-latest
     steps:
@@ -86,7 +111,7 @@ jobs:
         with:
           node-version: 22
           cache: 'pnpm'
-          cache-dependency-path: apps/frontend/pnpm-lock.yaml
+          cache-dependency-path: pnpm-lock.yaml
 
       - name: Install frontend dependencies
         run: |
@@ -114,12 +139,12 @@ jobs:
         with:
           node-version: 22
           cache: 'pnpm'
-          cache-dependency-path: apps/frontend/pnpm-lock.yaml
+          cache-dependency-path: pnpm-lock.yaml
 
       - name: Install frontend dependencies
         run: |
           cd apps/frontend
-          pnpm install
+          pnpm install --frozen-lockfile
 
       - name: Build frontend
         run: |

.github/workflows/verify.yml

@@ -11,18 +11,15 @@ on:
 
 
 jobs:
-  # setup is now handled by a composite action used by downstream jobs to keep
-  # the workflow DRY. The composite action performs checkout, cache restore and
-  # toolchain setup.
 
-  verify-generated-code:
+  verify-generated-database-code:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
         uses: actions/checkout@v3
         with:
           fetch-depth: 0
-          
+
       - name: Setup Rust, checkout and restore caches
         uses: ./.github/actions/setup-rust
 
@@ -32,14 +29,62 @@ jobs:
           cargo run -- db:migrate_and_generate --output-path ../../public/database/src/generated/entities
       - name: Check for uncommitted changes in /generated/
         run: |
-          if [[ -n $(git status --porcelain | grep '^ M .*\/generated\/') ]]; then
+          if [[ -n $(git status --porcelain --untracked-files=all | grep '/generated/') ]]; then
             echo "Generated code is not up to date. Please run the code generation locally and commit the changes."
-            git status --porcelain | grep '^ M .*\/generated\/'
+            git status --porcelain --untracked-files=all | grep '/generated/'
             exit 1
           else
             echo "Generated code is up to date."
           fi
 
+  verify-generated-agent-code:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-java@v5
+        with:
+          distribution: 'temurin'
+          java-version: '21'
+
+      - name: Setup Rust, checkout and restore caches
+        uses: ./.github/actions/setup-rust
+
+      - name: Setup PNPM
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+          run_install: false
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: 'pnpm'
+          cache-dependency-path: pnpm-lock.yaml
+
+      - name: Install root dependencies
+        run: |
+          pnpm install --frozen-lockfile
+
+      - name: generate agent client code
+        run: |
+          pnpm just generate-agent-client
+
+
+      - name: Check for uncommitted changes in agent client code
+        run: |
+          if [[ -n $(git status --porcelain --untracked-files=all | grep 'public/agent-client/') ]]; then
+            echo "Agent client code is not up to date. Please run the agent client code generation locally and commit the changes."
+            git status --porcelain --untracked-files=all | grep 'public/agent-client/'
+            exit 1
+          else
+            echo "Agent client code is up to date."
+          fi
+
   verify-openapi-spec:
     runs-on: ubuntu-latest
     steps:
@@ -83,7 +128,7 @@ jobs:
       - name: Setup Rust, checkout and restore caches
         if: steps.check_changes.outputs.changed == 'true'
         uses: ./.github/actions/setup-rust
-      
+
       - name: Generate dummy frontend build (to satisfy dependencies)
         if: steps.check_changes.outputs.changed == 'true'
         run: |
@@ -95,13 +140,13 @@ jobs:
         run: |
           cd apps/api
           cargo run -- generate:openapi --output-path ./swagger.json
-      
+
       - name: Check for uncommitted changes in swagger.json
         if: steps.check_changes.outputs.changed == 'true'
         run: |
-          if [[ -n $(git status --porcelain | grep '^ M apps/api/swagger.json') ]]; then
+          if [[ -n $(git status --porcelain --untracked-files=all | grep 'apps/api/swagger.json') ]]; then
             echo "OpenAPI spec is not up to date. Please run the OpenAPI generation locally and commit the changes."
-            git status --porcelain | grep '^ M apps/api/swagger.json'
+            git status --porcelain --untracked-files=all | grep 'apps/api/swagger.json'
             exit 1
           else
             echo "OpenAPI spec is up to date."
@@ -165,14 +210,14 @@ jobs:
         with:
           node-version: 22
           cache: 'pnpm'
-          cache-dependency-path: apps/frontend/pnpm-lock.yaml
-      
+          cache-dependency-path: pnpm-lock.yaml
+
       - name: Install frontend dependencies
         if: steps.check_swagger_changes.outputs.changed == 'true'
         run: |
           cd apps/frontend
           pnpm install
-      
+
       - name: Generate frontend API client
         if: steps.check_swagger_changes.outputs.changed == 'true'
         run: |
@@ -182,14 +227,14 @@ jobs:
       - name: Check for uncommitted changes in frontend API client
         if: steps.check_swagger_changes.outputs.changed == 'true'
         run: |
-          if [[ -n $(git status --porcelain | grep '^ M apps/frontend/app/generated/api-client') ]]; then
+          if [[ -n $(git status --porcelain --untracked-files=all | grep 'apps/frontend/app/generated/api-client') ]]; then
             echo "Frontend API client is not up to date. Please run the API client generation locally and commit the changes."
-            git status --porcelain | grep '^ M apps/frontend/app/generated/api-client'
+            git status --porcelain --untracked-files=all | grep 'apps/frontend/app/generated/api-client'
             exit 1
           else
             echo "Frontend API client is up to date."
           fi
-      
+
       - name: Skip frontend API client generation (no relevant changes)
         if: steps.check_swagger_changes.outputs.changed == 'false'
         run: echo "No changes in apps/api/swagger.json nor apps/frontend/app/generated/api-client, skipping frontend API client generation verification."

.gitignore

@@ -27,3 +27,5 @@ target
 .env.generated
 
 generated-config.yaml
+
+node_modules/

.vscode/settings.json

@@ -1,3 +1,12 @@
 {
-  "cSpell.words": ["YANPM"]
+  "cSpell.words": ["chrono", "jsonwebtoken", "oneshot", "utoipa", "YANPM"],
+  "sqltools.useNodeRuntime": true,
+  "sqltools.connections": [
+    {
+      "previewLimit": 50,
+      "driver": "SQLite",
+      "database": "${workspaceFolder:yet-another-nginx-proxy-manager}/apps/container/generated/sqlite/sqlite.db",
+      "name": "YANPM"
+    }
+  ]
 }

Cargo.toml

@@ -1,8 +1,10 @@
 [workspace]
-members = [ 
+members = [
     "apps/api",
     "apps/container",
     "apps/cli",
+    "apps/agent",
+    "public/agent-client",
     "public/shared",
     "public/database",
     "public/migration"

apps/agent/.gitignore

@@ -0,0 +1 @@
+*.sock

apps/agent/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "yanpm-agent"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+axum = { version = "0.8.7", features = ["form", "http1", "json", "matched-path", "original-uri", "query", "tokio", "tower-log", "tracing", "macros"] }
+tokio = { version = "1", features = ["fs", "io-util", "io-std", "macros", "net", "parking_lot", "process", "rt", "rt-multi-thread", "signal", "sync", "time", "tracing"] }
+tracing = { version = "0.1.41", features = ["std", "attributes"] }
+tracing-subscriber = { version = "0.3.20", features = ["smallvec", "fmt", "ansi", "tracing-log", "std", "json", "serde", "serde_json", "time", "tracing"] }
+serde_json = { version = "1.0.145", features = ["std"] }
+serde = { version = "1.0.228", features = ["std", "derive"] }
+tokio-cron-scheduler = { version = "0.15.1", features = ["signal"] }
+clap = { version = "4", features = ["derive", "env"] }
+nix = { version = "0.30.1", features = ["user", "fs"] }
+utoipa = { version = "5.4.0", features = ["macros", "axum_extras", "chrono", "decimal", "uuid", "time", "openapi_extensions"] }

apps/agent/Dockerfile

@@ -0,0 +1,56 @@
+FROM rust:1.92-alpine3.23 AS builder
+
+# Install build deps and binutils (for strip)
+RUN apk add --no-cache build-base musl-dev openssl-dev pkgconfig ca-certificates curl binutils
+WORKDIR /app
+
+# Copy manifest first to leverage Docker layer caching for dependencies
+COPY ./Cargo.toml ./
+RUN cargo fetch --locked || true
+
+COPY ./src ./src
+
+# Build the release binary and strip it to reduce size
+RUN cargo build --release --bin yanpm-agent && \
+  strip target/release/yanpm-agent || true
+
+FROM nginx:mainline-alpine3.23 AS base
+
+# Expose typical HTTP ports used by nginx
+EXPOSE 80 443
+
+ENV S6_KEEP_ENV=1
+ENV YANPM_AGENT_SOCK=/var/run/yanpm/yanpm-agent.sock
+ENV YANPM_NGINX_CONFIG_DIR=/etc/nginx/conf.d
+ENV YANPM_AGENT_SOCK_PERM=660
+ENV YANPM_AGENT_SOCK_GID=""
+ENV YANPM_AGENT_UID=1000
+ENV YANPM_AGENT_GID=1000
+
+WORKDIR /app
+
+# Install ca-certificates for TLS and minimal tools
+RUN apk add --no-cache ca-certificates curl
+
+# Install s6-overlay
+ENV S6_OVERLAY_VERSION=v3.2.1.0
+ADD https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-noarch.tar.xz /tmp
+RUN tar -C / -Jxpf /tmp/s6-overlay-noarch.tar.xz && rm /tmp/s6-overlay-noarch.tar.xz
+ADD https://github.com/just-containers/s6-overlay/releases/download/${S6_OVERLAY_VERSION}/s6-overlay-x86_64.tar.xz /tmp/s6-overlay.tar.xz
+RUN tar -C / -Jxpf /tmp/s6-overlay.tar.xz && rm /tmp/s6-overlay.tar.xz
+
+# Runtime user creation handled by s6 cont-init (see /etc/cont-init.d)
+# create directory for yanpm agent socket; ownership will be fixed at container start
+RUN mkdir -p /var/run/yanpm
+
+# Copy s6 service definitions (created in repo under s6/) into image
+COPY ./docker/s6/services.d /etc/services.d
+COPY ./docker/s6/cont-init.d /etc/cont-init.d
+RUN chmod +x /etc/services.d/*/run && chmod +x /etc/cont-init.d/*
+
+COPY --from=builder /app/target/release/yanpm-agent ./yanpm-agent
+
+RUN chmod +x /app/yanpm-agent
+
+# s6-overlay provides /init as the init process
+ENTRYPOINT ["/init"]

apps/agent/doc/README.md

@@ -0,0 +1,19 @@
+# yanpm-agent Documentation
+
+This directory contains in-depth documentation for the yanpm agent daemon (the binary built from `apps/agent`). The agent exposes a unix-socket HTTP API for writing nginx configuration fragments, validating them, and reloading nginx safely.
+
+Docs included:
+
+- `architecture.md` — Detailed explanation of the program flow and components.
+- `configuration.md` — CLI flags, environment variables, defaults, and permission handling.
+- `usage.md` — How to run the agent, curl examples, and systemd/docker hints.
+- `api.md` — HTTP API endpoints, request and response schemas, examples.
+- `deployment.md` — Deployment considerations, permissions, and systemd socket/unit examples.
+- `troubleshooting.md` — Common errors and solutions.
+
+For implementation details, see the source in `apps/agent/src` (notably `main.rs`, `routes.rs`, and the `commands/` submodule).
+
+Integration notes
+
+- The agent is intended to run as a companion agent for the API service in `apps/api`. The API service calls the agent over the unix-domain socket to write nginx fragments, validate them, and trigger reloads.
+- A production Docker image is provided by `apps/agent/Dockerfile`. That Dockerfile packages nginx + the `yanpm-agent` binary and s6-overlay service scripts so a single container can run nginx and the agent alongside each other.

apps/agent/doc/api.md

@@ -0,0 +1,68 @@
+# HTTP API Reference
+
+Base: HTTP over a unix-domain socket. Example using curl: `curl --unix-socket /path/to/socket -X POST http://localhost/<path>`
+
+1) GET /status
+
+   - Response: 200 OK
+   - Body: JSON `{ "ok": true }`
+
+2) POST /validate
+
+   - Request JSON:
+
+   ```json
+   {
+     "config_name": "example",
+     "timestamp": 1234567890
+   }
+   ```
+
+   - Behavior: validates the fragment file named by `config_name` and `timestamp` under the agent's internal subdirectory inside the configured nginx config directory. Delegates to `ValidateCommand::validate`.
+   - Success: 200 OK, body is `[rc, output]` tuple serialized as JSON (actual shape is `(i32, String)` returned from the command; examine responses for exact formatting).
+   - Error cases:
+     - 400 Bad Request: invalid or malformed JSON
+     - 500 Internal Server Error: validation error or missing fragment file
+
+   - Request JSON:
+
+   ```json
+   {
+      "config_name": "example",
+      "timestamp": 1234567890
+   }
+   ```
+
+   - Behavior: validates the fragment file named by `config_name` and `timestamp` under the agent's internal subdirectory inside the configured nginx config directory. Delegates to `ValidateCommand::validate`.
+   - Success: 200 OK, body is a JSON array `[rc, output]` where `rc` is the integer return code and `output` is the combined stdout/stderr string from the validation command (the command returns an `(i32, String)` tuple).
+   - Error cases:
+      - 400 Bad Request: invalid or malformed JSON
+      - 500 Internal Server Error: validation error or missing fragment file
+
+3) POST /validate_and_reload
+
+   - Request JSON same as `/validate`.
+   - Behavior: runs validation and, on success, attempts to reload nginx. Returns an object with `rc` and `ro` (return code and combined stdout/stderr output).
+   - Success: 200 OK with body: `{ "rc": <int>, "ro": "<output>" }`
+   - Errors: 400 for malformed JSON, 500 if the validate-and-reload command fails (body presents error text).
+
+4) POST /write_config
+
+   - Request JSON:
+
+   ```json
+   {
+     "config_name": "example",
+     "timestamp": 1234567890,
+     "content": "server { ... }"
+   }
+   ```
+
+   - Behavior: writes the provided `content` into an agent-managed fragment file named from `config_name` and `timestamp` in the internal subdirectory under `nginx_config_dir`.
+   - Success: 200 OK with empty body
+   - Error: 400 for malformed JSON, 500 if writing the file fails
+
+Notes
+
+- The agent expects callers to choose a `config_name` and `timestamp` that together form a unique filename. The concrete filename encoding is performed by `commands::run::to_file_name` in source.
+- On validation failures the returned output often contains the full `nginx -t` output; inspect `ro` or the returned JSON error messages.

apps/agent/doc/architecture.md

@@ -0,0 +1,34 @@
+# Architecture and Runtime Flow
+
+Overview
+
+- The agent is an async HTTP server (axum) listening on a Unix domain socket and exposes a small JSON API to manage nginx configuration fragments.
+- Core lifecycle is implemented in `apps/agent/src/main.rs`:
+  - parse CLI args and environment variables
+  - ensure the socket path and directory exist and have permissive but secure defaults
+  - bind a `tokio::net::UnixListener` to the socket
+  - create an `NginxService` (shared state) and an in-process cron `JobScheduler`
+  - mount axum routes (`/status`, `/validate`, `/validate_and_reload`, `/write_config`) and serve HTTP over the Unix socket
+
+Key components
+
+- `main.rs` — Bootstrapping, argument handling, socket setup and permission handling, scheduler start, and axum server startup.
+- `routes.rs` — axum handlers for the HTTP API. It deserializes JSON payloads and delegates to `NginxService` methods. Handlers return appropriate HTTP status codes and JSON on error or success.
+- `commands/` — Implementation of lower-level actions (writing fragment files, running `nginx -t`, validating, reloads). The `validate.rs` command contains sophisticated behavior to handle permission-limited environments by:
+  - creating wrapper nginx configs that include a single fragment
+  - trying `nginx -t` directly, attempting a privileged wrapper via `sudo` if available, and finally passing a writable PID override via `-g pid ...;` to avoid permission failures
+
+Concurrency and state
+
+- A single shared `NginxService` instance is stored in axum `State` and cloned into handlers; it holds the scheduler and the configured nginx config directory path.
+- The JobScheduler is created with `tokio_cron_scheduler::JobScheduler` and started before serving requests.
+
+Error handling and best-effort behavior
+
+- Socket permission changes, GID changes, and directory creations are best-effort and log warnings on failure rather than failing hard.
+- Most command failures are converted into JSON errors with appropriate HTTP status codes so callers can inspect command output.
+
+Integration and packaging
+
+- The agent is intended to run as a companion to the API server in `apps/api`. The API calls the agent over the unix socket to write fragments, validate them, and trigger reloads.
+- `apps/agent/Dockerfile` builds a runtime image that includes `nginx` and the `yanpm-agent` binary (the Dockerfile uses s6-overlay to run multiple services). This image is suitable for deployments that prefer nginx and the agent colocated in a single container.

apps/agent/doc/configuration.md

@@ -0,0 +1,27 @@
+# Configuration and Environment
+
+CLI flags and environment variables
+
+- `--sock` / `YANPM_AGENT_SOCK` (default: `./yanpm-agent.sock`)
+  - Path to the Unix socket file the agent will bind to.
+  - If the socket directory does not exist the agent attempts to create it and set mode `0770`.
+
+- `--nginx-config-dir` / `YANPM_NGINX_CONFIG_DIR` (default: `/etc/nginx/conf.d`)
+  - Directory where nginx fragments are written. The agent writes fragments into a subdirectory named by the agent (internal use).
+
+- `--sock-perm` / `YANPM_AGENT_SOCK_PERM` (default: `660`)
+  - A 3-digit octal permission string applied to the socket file (best-effort). The program validates this is a 3-digit octal string.
+  - If the final digit is greater than `0` a warning is logged because that allows "others" access.
+
+- `--sock-gid` / `YANPM_AGENT_SOCK_GID` (default: current user's primary group)
+  - GID to set on the socket file (best-effort).
+
+Validation rules and behavior
+
+- `sock_perm` must be exactly 3 octal digits (characters 0-7). The agent rejects invalid values at startup.
+- When an existing path exists at the socket location the agent verifies it is a unix socket; if so it removes it before binding. If the path exists and is not a socket, startup fails.
+- Setting permissions (`set_permissions`) and changing GID (`chown`) are attempted but non-fatal: failures are logged as warnings and the agent continues.
+
+Notes about nginx config directory
+
+- The agent writes fragments into a subdirectory (internal) of the configured `nginx_config_dir`. Ensure nginx is configured to include that subdirectory so fragments are picked up, or use `write_config` then trigger a reload.

apps/agent/doc/deployment.md

@@ -0,0 +1,62 @@
+# Deployment and Permissions
+
+Socket location and permissions
+
+- The agent binds a unix socket at the path given by `--sock` or `YANPM_AGENT_SOCK`. The agent will:
+  - create the parent directory (best-effort) and attempt to set its permissions to `0770`
+  - remove an existing socket file if it is a socket, or fail if the path exists and is not a socket
+  - apply the `sock_perm` (3-digit octal) to the socket file and optionally change its GID to `sock_gid`
+
+Systemd socket/unit example
+
+Create a `yanpm-agent.socket` unit that creates and owns the unix socket, and a `yanpm-agent.service` that runs the agent. Ensure the socket path used by systemd matches `--sock`.
+
+Docker / container notes
+
+- If running the agent inside a container and writing to host nginx config, bind-mount the host nginx config directory into the container at the path provided to `--nginx-config-dir`.
+- Consider running the agent as a user with permission to write the nginx config directory or use a shared group and `sock_gid` so clients can access the socket.
+- The repository provides a runtime image built by `apps/agent/Dockerfile` which packages `nginx` together with the `yanpm-agent` binary and s6-overlay service scripts. This image runs nginx and the agent in one container which is useful when the agent is acting as the runtime companion for the API (`apps/api`).
+
+Privilege escalation for validation
+
+- In many systems `nginx -t` may fail due to inability to access `/run/nginx.pid` or other privileged files. The agent attempts a best-effort sequence:
+
+ 1. Run `nginx -t` directly.
+ 2. If that fails with permission errors, try a privileged wrapper (e.g. `/usr/local/sbin/yanpm-nginx-validate` or `yanpm-nginx-validate-file`) via `sudo -n`.
+ 3. If wrapper is unavailable or fails, retry `nginx -t` with a writable PID override via `-g 'pid /tmp/yanpm-validate-<pid>.pid;'`.
+
+Security considerations
+
+- Avoid setting `sock_perm` to allow world access unless explicitly intended.
+- Prefer controlling socket group membership via `sock_gid` rather than making the socket world-writable.
+
+s6 init scripts, wrappers and sudoers (runtime)
+
+- Purpose: The image built by `apps/agent/Dockerfile` uses `s6-overlay` as PID 1 (the Dockerfile sets `ENTRYPOINT ["/init"]`). The repository includes `docker/s6/cont-init.d` scripts that run at container startup (one-shot) and `docker/s6/services.d` entries to run long-lived services (nginx and the agent). The cont-init scripts prepare runtime users, permissions, and helper wrappers the agent uses for privileged operations.
+
+- Key cont-init scripts (in the repo):
+  - `docker/s6/cont-init.d/10-create-app-user` — ensures the `yanpm-agent` user and group exist (honoring `YANPM_AGENT_UID`, `YANPM_AGENT_GID`, and `YANPM_AGENT_SOCK_GID`), adds the user to the `nginx` group, and attempts to chown runtime directories like `/var/run/yanpm` and `/app/yanpm-agent` (logs warnings if chown fails for bind mounts or rootless containers).
+  - `docker/s6/cont-init.d/20-install-reload-wrapper` — installs three helper wrappers and a sudoers entry so the `yanpm-agent` user can perform narrowly-scoped privileged operations without a password.
+
+- Wrapper scripts installed by `20-install-reload-wrapper`:
+  - `/usr/local/sbin/yanpm-nginx-reload` — runs `nginx -c /etc/nginx/nginx.conf -s reload` (used for reloading the running nginx master process).
+  - `/usr/local/sbin/yanpm-nginx-validate` — runs `nginx -c /etc/nginx/nginx.conf -t` (validates the main nginx config).
+  - `/usr/local/sbin/yanpm-nginx-validate-file` — securely validates a single nginx config file: it resolves the absolute path, ensures the target is a regular file (not a symlink), checks the file is owned by the `yanpm-agent` user, enforces it's not world-writable, then runs `nginx -c <file> -t`. This defends against symlink and race attacks when an unprivileged agent requests privileged validation.
+
+- Sudoers entry:
+  - The init script writes `/etc/sudoers.d/yanpm-agent` with a rule allowing the configured agent user (default `yanpm-agent`) to run only the three wrappers with `NOPASSWD`. This gives the agent a limited, auditable privilege escalation surface; the agent code attempts to use these wrappers via `sudo -n` before falling back to less privileged strategies.
+
+- Relevant environment variables (settable in the Dockerfile or at runtime):
+  - `YANPM_AGENT_SOCK` — unix socket path (default set in Dockerfile: `/var/run/yanpm/yanpm-agent.sock`).
+  - `YANPM_NGINX_CONFIG_DIR` — nginx config dir (default `/etc/nginx/conf.d`).
+  - `YANPM_AGENT_SOCK_PERM` — socket permissions (octal string, default `660`).
+  - `YANPM_AGENT_SOCK_GID` — desired GID for the socket (optional).
+  - `YANPM_AGENT_UID`, `YANPM_AGENT_GID` — runtime UID/GID used to create the `yanpm-agent` user in the container.
+
+- How the agent uses these runtime helpers:
+  - `ValidateCommand` and `ReloadCommand` in the agent code try `nginx` operations directly; when permission problems occur they attempt the privileged wrappers via `sudo -n /usr/local/sbin/yanpm-nginx-validate` or `...-validate-file` and `...-reload`. The cont-init script's wrappers plus the sudoers entry implement that intended secure upgrade path.
+
+- Notes and recommendations:
+  - The `validate-file` wrapper performs ownership and permission checks; ensure written fragments are created by the `yanpm-agent` user (the agent writes files as that user when running inside the container due to `10-create-app-user`).
+  - The cont-init scripts attempt to install `sudo` if missing; in minimal images you may prefer providing `sudo` at build time to avoid runtime installation attempts.
+  - If you bind-mount host directories (e.g., `/etc/nginx/conf.d`) into the container, ensure ownership and permissions are compatible with the agent user and `YANPM_AGENT_SOCK_GID` so the socket and files are accessible as intended.

apps/agent/doc/troubleshooting.md

@@ -0,0 +1,27 @@
+# Troubleshooting
+
+Common issues and how to resolve them
+
+- Socket path exists but is not a socket
+  - Symptom: startup fails with an error that the socket path exists and is not a socket.
+  - Fix: remove the file at the socket path or choose a different `--sock` path.
+
+- Permission denied on socket directory or socket
+  - Symptom: socket creation or permission setting logs warnings; clients cannot connect.
+  - Fix: ensure the socket directory exists and has correct ownership/group and that `sock_perm` and `sock_gid` are configured appropriately. Consider using `chown`/`chmod` from a privileged context.
+
+- `nginx -t` fails with `/run/nginx.pid: Permission denied`
+  - Symptom: validation fails; output contains permission denied for `/run/nginx.pid`.
+  - Fixes (tried by the agent):
+    1. If available, provide a privileged validation wrapper (e.g. `/usr/local/sbin/yanpm-nginx-validate`) that runs `nginx -t` with appropriate privileges.
+    2. Ensure the agent-runner has permission to read the main nginx configuration and `/run/nginx.pid` or allow the agent to use a writable PID override.
+
+- Fragment file not found during validation
+  - Symptom: validate returns 500 with message `Config file not found`.
+  - Fix: make sure the fragment has been written via `/write_config` to the agent's internal subdirectory under `NGINX_CONFIG_DIR`, using the same `config_name` and `timestamp` as the validate call.
+
+- Wrapper or sudo not available
+  - Symptom: attempts to run `sudo -n /usr/local/sbin/yanpm-nginx-validate` fail.
+  - Fix: install a wrapper script that allows unprivileged `sudo -n` validation or configure proper permissions on nginx state files.
+
+If none of the above solves the problem, collect the logs produced by the agent (it uses `tracing`/`tracing_subscriber`) and include the exact command outputs from the validation steps when asking for help.

apps/agent/doc/usage.md

@@ -0,0 +1,61 @@
+# Usage and Examples
+
+Running locally (development)
+
+1. Build the agent (from repository root):
+
+   ```sh
+   cargo build -p agent
+   ```
+
+2. Run the agent with defaults (socket in current directory):
+
+   ```sh
+   ./target/debug/yanpm-agent
+   ```
+
+3. Run with explicit socket and nginx config directory:
+
+   ```sh
+   ./target/debug/yanpm-agent --sock /run/yanpm/yanpm-agent.sock --nginx-config-dir /etc/nginx/conf.d
+   ```
+
+HTTP over unix-socket examples (using `socat` / `curl` helper)
+
+If you want to call the API from the shell, you can use `socat` to convert the unix socket to an HTTP stream, or use tools that support unix sockets directly (e.g. `curl --unix-socket`). Examples below use `curl --unix-socket`.
+
+Validate a fragment by name and timestamp:
+
+```sh
+curl --unix-socket ./yanpm-agent.sock -X POST http://localhost/validate \
+  -H 'Content-Type: application/json' \
+  -d '{"config_name":"example","timestamp":1234567890}'
+```
+
+Validate and reload (returns `rc` and `ro`):
+
+```sh
+curl --unix-socket ./yanpm-agent.sock -X POST http://localhost/validate_and_reload \
+  -H 'Content-Type: application/json' \
+  -d '{"config_name":"example","timestamp":1234567890}'
+```
+
+Write a fragment (create or update):
+
+```sh
+curl --unix-socket ./yanpm-agent.sock -X POST http://localhost/write_config \
+  -H 'Content-Type: application/json' \
+  -d '{"config_name":"example","timestamp":1234567890,"content":"server { listen 80; server_name example.local; }"}'
+```
+
+Status endpoint (health)
+
+```sh
+curl --unix-socket ./yanpm-agent.sock http://localhost/status
+```
+
+Notes
+
+- Use the `config_name` and `timestamp` fields consistently: `timestamp` is typically a monotonic update ID from the caller ensuring unique file names.
+- When running in containers, mount the host nginx config dir if you want the agent to write directly to host nginx configuration.
+- The repository includes a runtime Docker image built by `apps/agent/Dockerfile` which bundles `nginx` and the `yanpm-agent` binary (via s6-overlay). Use that image when you want nginx and the agent colocated (the agent is intended as a runtime companion to `apps/api`).

apps/agent/docker/s6/cont-init.d/10-create-app-user

@@ -0,0 +1,58 @@
+#!/bin/sh
+set -eu
+
+YANPM_AGENT_UID="${YANPM_AGENT_UID:-1000}"
+YANPM_AGENT_GID="${YANPM_AGENT_GID:-1000}"
+# If a specific socket GID is requested, prefer that for the app group
+YANPM_AGENT_GID_EFFECTIVE="${YANPM_AGENT_SOCK_GID:-${YANPM_AGENT_GID}}"
+YANPM_AGENT_USER="${YANPM_AGENT_USER:-yanpm-agent}"
+YANPM_AGENT_GROUP="${YANPM_AGENT_GROUP:-yanpm-agent}"
+
+# Ensure group exists with desired GID
+if grep -qE "^${YANPM_AGENT_GROUP}:" /etc/group 2>/dev/null; then
+  existing_gid=$(awk -F: -v g="${YANPM_AGENT_GROUP}" '$1==g{print $3}' /etc/group)
+  if [ "${existing_gid}" != "${YANPM_AGENT_GID_EFFECTIVE}" ]; then
+    delgroup "${YANPM_AGENT_GROUP}" || true
+    addgroup -g "${YANPM_AGENT_GID_EFFECTIVE}" "${YANPM_AGENT_GROUP}"
+  fi
+else
+  addgroup -g "${YANPM_AGENT_GID_EFFECTIVE}" "${YANPM_AGENT_GROUP}"
+fi
+
+# Ensure user exists with desired UID and primary group
+if grep -qE "^${YANPM_AGENT_USER}:" /etc/passwd 2>/dev/null; then
+  existing_uid=$(awk -F: -v u="${YANPM_AGENT_USER}" '$1==u{print $3}' /etc/passwd)
+  if [ "${existing_uid}" != "${YANPM_AGENT_UID}" ]; then
+    deluser "${YANPM_AGENT_USER}" || true
+    adduser -D -u "${YANPM_AGENT_UID}" -G "${YANPM_AGENT_GROUP}" "${YANPM_AGENT_USER}"
+  fi
+else
+  adduser -D -u "${YANPM_AGENT_UID}" -G "${YANPM_AGENT_GROUP}" "${YANPM_AGENT_USER}"
+fi
+
+# Add app user to nginx group to allow reading configs
+addgroup "${YANPM_AGENT_USER}" nginx || true
+# Ensure runtime directories exist and fix ownership
+
+mkdir -p /var/run/yanpm /app
+if chown -R "${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}" /var/run/yanpm 2>/dev/null; then
+  echo "chown: /var/run/yanpm -> ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}"
+else
+  echo "Warning: failed to chown /var/run/yanpm to ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}. This is common for bind-mounted host volumes or rootless Docker." >&2
+fi
+
+if chown -R "${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}" /app/yanpm-agent 2>/dev/null; then
+  echo "chown: /app/yanpm-agent -> ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}"
+else
+  echo "Warning: failed to chown /app/yanpm-agent to ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}. Binary will still be used if permissions allow." >&2
+fi
+
+if chown "${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}" /app 2>/dev/null; then
+  echo "chown: /app -> ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}"
+else
+  echo "Warning: failed to chown /app to ${YANPM_AGENT_UID}:${YANPM_AGENT_GID_EFFECTIVE}." >&2
+fi
+
+echo "App user and group setup complete. UID:${YANPM_AGENT_UID} GID:${YANPM_AGENT_GID_EFFECTIVE}"
+
+exit 0

apps/agent/docker/s6/cont-init.d/20-install-reload-wrapper

@@ -0,0 +1,170 @@
+#!/bin/sh
+set -eu
+
+# This init script installs a minimal nginx reload wrapper and a sudoers
+# entry so the `yanpm-agent` user can perform a controlled reload via sudo.
+
+WRAPPER_PATH="/usr/local/sbin/yanpm-nginx-reload"
+SUDOERS_PATH="/etc/sudoers.d/yanpm-agent"
+AGENT_USER="${YANPM_AGENT_USER:-yanpm-agent}"
+
+# validate wrapper
+VALIDATE_PATH="/usr/local/sbin/yanpm-nginx-validate"
+# validate file wrapper
+VALIDATE_FILE_PATH="/usr/local/sbin/yanpm-nginx-validate-file"
+
+echo "[cont-init.d] install-reload-wrapper: setting up nginx reload helper"
+
+# find nginx binary
+NGINX_BIN="$(command -v nginx || true)"
+if [ -z "${NGINX_BIN}" ]; then
+  echo "Warning: nginx binary not found in PATH; wrapper will still be created but may fail at runtime." >&2
+  NGINX_BIN="/usr/sbin/nginx"
+fi
+
+# Create wrapper
+mkdir -p /usr/local/sbin /etc/sudoers.d
+
+cat > "${WRAPPER_PATH}" <<- 'EOF'
+#!/bin/sh
+exec "@NGINX_BIN@" -c /etc/nginx/nginx.conf -s reload
+EOF
+
+# Replace placeholder with actual path
+sed -i "s|@NGINX_BIN@|${NGINX_BIN}|g" "${WRAPPER_PATH}" || true
+
+chmod 0750 "${WRAPPER_PATH}"
+chown root:root "${WRAPPER_PATH}" || true
+
+#
+#
+#
+
+# Create validate wrapper
+cat > "${VALIDATE_PATH}" <<- 'EOF'
+#!/bin/sh
+exec "@NGINX_BIN@" -c /etc/nginx/nginx.conf -t
+EOF
+
+# Replace placeholder with actual path in validate wrapper
+sed -i "s|@NGINX_BIN@|${NGINX_BIN}|g" "${VALIDATE_PATH}" || true
+
+chmod 0750 "${VALIDATE_PATH}"
+chown root:root "${VALIDATE_PATH}" || true
+
+#
+#
+#
+
+# Create validate file wrapper (secure)
+cat > "${VALIDATE_FILE_PATH}" <<-'EOF'
+#!/bin/sh
+set -eu
+
+if [ $# -ne 1 ]; then
+  echo "Usage: $0 <nginx-config-file>" >&2
+  exit 2
+fi
+
+INPUT="$1"
+
+# Resolve absolute path
+if command -v readlink >/dev/null 2>&1; then
+  TARGET="$(readlink -f -- "$INPUT" 2>/dev/null || true)"
+elif command -v realpath >/dev/null 2>&1; then
+  TARGET="$(realpath -- "$INPUT" 2>/dev/null || true)"
+else
+  echo "Error: no path resolver (readlink/realpath) available" >&2
+  exit 3
+fi
+
+if [ -z "$TARGET" ]; then
+  echo "Error: cannot resolve path: $INPUT" >&2
+  exit 4
+fi
+
+# Must be a regular file and not a symlink
+if [ ! -f "$TARGET" ] || [ -L "$TARGET" ]; then
+  echo "Error: ${TARGET} is not a regular file" >&2
+  exit 5
+fi
+
+# must be created by agent user
+AGENT_UID="$(id -u yanpm-agent 2>/dev/null || true)"
+if [ -z "$AGENT_UID" ]; then
+  echo "Error: yanpm-agent user not found" >&2
+  exit 6
+fi
+
+FILE_UID="$(stat -c %u -- "$TARGET" 2>/dev/null || true)"
+if [ "$FILE_UID" != "$AGENT_UID" ]; then
+  echo "Error: ${TARGET} not owned by yanpm-agent user" >&2
+  exit 7
+fi
+
+# Ensure file is not world-writable; allow typical 664 (rw-rw-r--)
+if command -v stat >/dev/null 2>&1; then
+  MODE="$(stat -c %a -- "$TARGET" 2>/dev/null || true)"
+  if [ -n "$MODE" ]; then
+    OTHERS=$(( MODE % 10 ))
+    if [ $(( OTHERS & 2 )) -ne 0 ]; then
+      echo "Error: ${TARGET} is world-writable" >&2
+      exit 8
+    fi
+  fi
+elif command -v find >/dev/null 2>&1; then
+  if find "$TARGET" -maxdepth 0 -perm /002 -print -quit >/dev/null 2>&1; then
+    echo "Error: ${TARGET} is world-writable" >&2
+    exit 8
+  fi
+fi
+
+exec "@NGINX_BIN@" -c "$TARGET" -t
+EOF
+
+# Replace placeholder with actual path in validate file wrapper
+sed -i "s|@NGINX_BIN@|${NGINX_BIN}|g" "${VALIDATE_FILE_PATH}" || true
+chmod 0750 "${VALIDATE_FILE_PATH}"
+chown root:root "${VALIDATE_FILE_PATH}" || true
+
+echo "Created wrapper: ${WRAPPER_PATH} (owned by root, mode 750)"
+
+#
+#
+#
+
+# Ensure sudoers entry exists allowing the agent to run only this wrapper as root
+if command -v sudo >/dev/null 2>&1; then
+  echo "sudo present; creating sudoers entry"
+  cat > "${SUDOERS_PATH}" <<- EOF
+# Allow ${AGENT_USER} to run the nginx reload and validate wrappers without a password
+${AGENT_USER} ALL=(root) NOPASSWD: ${WRAPPER_PATH}, ${VALIDATE_PATH}, ${VALIDATE_FILE_PATH}
+EOF
+  chmod 0440 "${SUDOERS_PATH}" || true
+  echo "Wrote sudoers entry: ${SUDOERS_PATH}"
+else
+  echo "sudo not found; attempting to install"
+  if command -v apk >/dev/null 2>&1; then
+    apk add --no-cache sudo || true
+  elif command -v apt-get >/dev/null 2>&1; then
+    apt-get update || true
+    apt-get install -y sudo || true
+  elif command -v yum >/dev/null 2>&1; then
+    yum install -y sudo || true
+  else
+    echo "No known package manager to install sudo; please ensure sudo is available in the image." >&2
+  fi
+
+  if command -v sudo >/dev/null 2>&1; then
+    cat > "${SUDOERS_PATH}" <<- EOF
+# Allow ${AGENT_USER} to run the nginx reload and validate wrappers without a password
+${AGENT_USER} ALL=(root) NOPASSWD: ${WRAPPER_PATH}, ${VALIDATE_PATH}, ${VALIDATE_FILE_PATH}
+EOF
+    chmod 0440 "${SUDOERS_PATH}" || true
+    echo "Installed sudo and wrote sudoers entry: ${SUDOERS_PATH}"
+  else
+    echo "Failed to install sudo; the agent will not be able to reload nginx via sudo." >&2
+  fi
+fi
+
+exit 0

apps/agent/docker/s6/services.d/agent/run

@@ -0,0 +1,5 @@
+#!/bin/sh
+# Run the agent as the unprivileged 'yanpm-agent' user
+cd /app
+echo "Starting yanpm-agent..."
+exec s6-setuidgid yanpm-agent ./yanpm-agent

apps/agent/docker/s6/services.d/nginx/run

@@ -0,0 +1,3 @@
+#!/bin/sh
+# Run nginx in foreground (s6 will supervise it)
+exec nginx -g 'daemon off;'

apps/agent/justfile

@@ -0,0 +1,2 @@
+build-docker:
+  docker build -t yanpm/agent:latest .

apps/agent/src/commands.rs

@@ -0,0 +1,292 @@
+mod reload;
+mod run;
+mod validate;
+mod write_config;
+
+use std::{
+    collections::HashMap,
+    sync::{
+        Arc,
+        atomic::{AtomicU64, Ordering},
+    },
+};
+
+use tokio::sync::{Mutex, RwLock};
+use tokio_cron_scheduler::{Job, JobScheduler};
+use tracing::{error, info};
+
+use crate::commands::write_config::INTERNAL_CONFIG_FOLDER_NAME;
+
+const OLD_CONFIG_CLEANUP_THRESHOLD: u64 = 3600;
+
+pub struct NginxService {
+    // lock for nginx reload, and timestamp tracking
+    nginx_lock: Mutex<()>,
+    last_applied: AtomicU64,
+    // lock for write_config per (config_name, timestamp)
+    #[allow(clippy::type_complexity)]
+    write_config_lock: RwLock<HashMap<(String, u64), Arc<RwLock<()>>>>,
+    // commands
+    reload_cmd: Arc<reload::ReloadCommand>,
+    validate_cmd: Arc<validate::ValidateCommand>,
+    write_config_cmd: Arc<write_config::WriteConfigCommand>,
+}
+
+impl NginxService {
+    pub async fn new(
+        scheduler: Arc<JobScheduler>,
+        nginx_config_dir: std::path::PathBuf,
+    ) -> Result<Arc<Self>, Box<dyn std::error::Error + Send + Sync>> {
+        let nginx_service = Arc::new(NginxService {
+            nginx_lock: Mutex::new(()),
+            last_applied: AtomicU64::new(0),
+            write_config_lock: RwLock::new(HashMap::new()),
+            // commands
+            reload_cmd: Arc::new(reload::ReloadCommand::default()),
+            validate_cmd: Arc::new(validate::ValidateCommand::new(nginx_config_dir.clone())),
+            write_config_cmd: Arc::new(write_config::WriteConfigCommand::new(nginx_config_dir)),
+        });
+        let mut nginx_service_clone = nginx_service.clone();
+
+        scheduler
+            .clone()
+            // cleanup every 10 minutes
+            .add(Job::new_async("0 */10 * * * *", move |_uuid, _l| {
+                info!("Running nginx_service cleanup job");
+                let nginx_service_clone = nginx_service_clone.clone();
+                let job = Box::pin(async move {
+                    nginx_service_clone.cleanup_unused_lock().await;
+                });
+                info!("NginxService cleanup job completed");
+                job
+            })?)
+            .await?;
+
+        nginx_service_clone = nginx_service.clone();
+
+        scheduler
+            .clone()
+            // cleanup every hour
+            .add(Job::new_async("0 0 */1 * * *", move |_uuid, _l| {
+                info!("Running nginx_service old config cleanup job");
+                let nginx_service_clone = nginx_service_clone.clone();
+                let job = Box::pin(async move {
+                    nginx_service_clone.cleanup_old_configs().await;
+                });
+                info!("NginxService old config cleanup job completed");
+                job
+            })?)
+            .await?;
+
+        Ok(nginx_service)
+    }
+
+    pub async fn validate_and_reload(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+    ) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+        let cur = self.last_applied.load(Ordering::SeqCst);
+        if cur > timestamp {
+            return Err("Another operation is in progress with higher timestamp value".into());
+        }
+
+        // acquire write lock to update nginx_lock
+        let _nginx_guard = self.nginx_lock.lock().await;
+        // acquire write lock for this config+timestamp
+        let rw_lock = self.acquire_file_write_lock(config_name, timestamp).await;
+        let _guard = rw_lock.write().await;
+
+        match self
+            .reload_cmd
+            .validate_and_reload(config_name, timestamp, self.validate_cmd.clone())
+            .await
+        {
+            Ok((code, output)) => {
+                // update last_applied
+                self.last_applied.store(timestamp, Ordering::SeqCst);
+                Ok((code, output))
+            }
+            Err(e) => Err(e),
+        }
+    }
+
+    pub async fn write_config(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+        content: &str,
+    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+        let rw_lock = self.acquire_file_write_lock(config_name, timestamp).await;
+        let _guard = rw_lock.write().await;
+        // call the write_config command
+        self.write_config_cmd
+            .write_config(config_name, timestamp, content)
+            .await
+    }
+
+    pub async fn validate(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+    ) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+        self.validate_cmd.validate(config_name, timestamp).await
+    }
+
+    async fn cleanup_unused_lock(&self) {
+        let mut _write_lock = self.write_config_lock.write().await;
+        (*_write_lock).retain(|_, lock| {
+            // retain only locks that are currently held (readers or writers)
+            lock.try_write().is_err()
+        });
+    }
+
+    async fn cleanup_old_configs(&self) {
+        // list all files within nginx_config_dir/YANPM that is older than now - OLD_CONFIG_CLEANUP_THRESHOLD
+        let cutoff = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_secs()
+            - OLD_CONFIG_CLEANUP_THRESHOLD;
+
+        let nginx_config_dir = self.validate_cmd.nginx_config_dir();
+        let yanpm_dir = nginx_config_dir.join(INTERNAL_CONFIG_FOLDER_NAME);
+
+        let read_dir = match tokio::fs::read_dir(&yanpm_dir).await {
+            Ok(rd) => rd,
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                // directory does not exist, nothing to clean up
+                return;
+            }
+            Err(e) => {
+                error!(
+                    "Error reading {} config directory {}: {}",
+                    INTERNAL_CONFIG_FOLDER_NAME,
+                    yanpm_dir.display(),
+                    e
+                );
+                return;
+            }
+        };
+
+        tokio::pin!(read_dir);
+        while let Some(entry) = read_dir.next_entry().await.unwrap_or(None) {
+            let metadata = match entry.metadata().await {
+                Ok(md) => md,
+                Err(e) => {
+                    error!(
+                        "Error getting metadata for file {}: {}",
+                        entry.path().display(),
+                        e
+                    );
+                    continue;
+                }
+            };
+            if let Ok(modified) = metadata.modified()
+                && let Ok(duration) = modified.duration_since(std::time::UNIX_EPOCH)
+            {
+                let mtime_secs = duration.as_secs();
+                if mtime_secs < cutoff {
+                    // file is older than cutoff, remove it
+                    if let Err(e) = tokio::fs::remove_file(entry.path()).await {
+                        error!(
+                            "Error removing old config file {}: {}",
+                            entry.path().display(),
+                            e
+                        );
+                    } else {
+                        info!("Removed old config file {}", entry.path().display());
+                    }
+                }
+            }
+        }
+    }
+
+    async fn acquire_file_write_lock(&self, config_name: &str, timestamp: u64) -> Arc<RwLock<()>> {
+        let mut write_lock = self.write_config_lock.write().await;
+        write_lock
+            .entry((config_name.to_string(), timestamp))
+            .or_insert_with(|| Arc::new(RwLock::new(())))
+            .clone()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::error::Error;
+    use std::sync::Arc as StdArc;
+    use tokio::time::{Duration, sleep};
+
+    impl NginxService {
+        // Test helper that simulates a long-running reload without invoking external commands.
+        pub async fn test_simulated_reload(
+            &self,
+            config_name: &str,
+            timestamp: u64,
+            delay_ms: u64,
+        ) -> Result<(), Box<dyn Error + Send + Sync>> {
+            // pre-check
+            let cur = self.last_applied.load(Ordering::SeqCst);
+            if cur >= timestamp {
+                return Err("stale".into());
+            }
+
+            // acquire exclusive lock and re-check
+            let _nginx_guard = self.nginx_lock.lock().await;
+            let cur2 = self.last_applied.load(Ordering::SeqCst);
+            if cur2 >= timestamp {
+                return Err("stale".into());
+            }
+
+            // per-file lock
+            let rw_lock = self.acquire_file_write_lock(config_name, timestamp).await;
+            let _guard = rw_lock.write().await;
+
+            // simulate operation
+            sleep(Duration::from_millis(delay_ms)).await;
+
+            // on success update last_applied
+            let mut prev = self.last_applied.load(Ordering::SeqCst);
+            while prev < timestamp {
+                match self.last_applied.compare_exchange(
+                    prev,
+                    timestamp,
+                    Ordering::SeqCst,
+                    Ordering::SeqCst,
+                ) {
+                    Ok(_) => break,
+                    Err(next) => prev = next,
+                }
+            }
+
+            Ok(())
+        }
+    }
+
+    #[tokio::test]
+    async fn concurrent_stale_is_rejected() {
+        let scheduler = StdArc::new(JobScheduler::new().await.unwrap());
+        let svc = NginxService::new(scheduler.clone(), std::env::temp_dir())
+            .await
+            .unwrap();
+
+        let s1 = svc.clone();
+        let h1 = tokio::spawn(async move { s1.test_simulated_reload("cfg", 2, 200).await });
+
+        // let second start shortly after first so it will wait for the mutex
+        sleep(Duration::from_millis(20)).await;
+
+        let s2 = svc.clone();
+        let h2 = tokio::spawn(async move { s2.test_simulated_reload("cfg", 1, 10).await });
+
+        let r1 = h1.await.unwrap();
+        assert!(r1.is_ok(), "first (newer) task should succeed");
+
+        let r2 = h2.await.unwrap();
+        assert!(
+            r2.is_err(),
+            "second (older) task should be rejected as stale"
+        );
+    }
+}

apps/agent/src/commands/reload.rs

@@ -0,0 +1,109 @@
+use std::path::Path;
+use std::sync::Arc;
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use tokio::sync::Mutex;
+use tracing::error;
+
+use crate::commands::write_config::INTERNAL_CONFIG_FOLDER_NAME;
+use crate::commands::{run::run_cmd, validate::ValidateCommand};
+
+pub struct ReloadCommand {
+    is_reloading: Mutex<bool>,
+}
+
+struct ReloadResetGuard<'a> {
+    guard: tokio::sync::MutexGuard<'a, bool>,
+}
+
+impl<'a> Drop for ReloadResetGuard<'a> {
+    fn drop(&mut self) {
+        *self.guard = false;
+    }
+}
+
+impl Default for ReloadCommand {
+    fn default() -> Self {
+        Self {
+            is_reloading: Mutex::new(false),
+        }
+    }
+}
+
+impl ReloadCommand {
+    pub async fn validate_and_reload(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+        validate_cmd: Arc<ValidateCommand>,
+    ) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+        // ensure the written fragment exists
+        validate_cmd.validate(config_name, timestamp).await?;
+
+        // Now atomically swap the YANPM.conf symlink to point to the new fragment
+        // so nginx -t validates the composed main config. If validation fails,
+        // attempt to restore the previous symlink.
+        let filename = crate::commands::run::to_file_name(config_name, timestamp)?;
+        let nginx_dir = validate_cmd.nginx_config_dir();
+        let symlink_path = nginx_dir.join("YANPM.conf");
+        let now = SystemTime::now().duration_since(UNIX_EPOCH)?.as_nanos();
+        let tmp_name = format!("YANPM.conf.tmp.{}.{}", std::process::id(), now);
+        let tmp_path = nginx_dir.join(&tmp_name);
+
+        // prepare relative target: INTERNAL_CONFIG_FOLDER_NAME/<filename>
+        let rel_target = Path::new(INTERNAL_CONFIG_FOLDER_NAME).join(&filename);
+
+        // read previous target if exists
+        let previous_target = std::fs::read_link(&symlink_path).ok();
+
+        // Acquire reload guard before mutating the symlink to avoid races
+        let reloading_lock = self.is_reloading.lock().await;
+        if *reloading_lock {
+            return Err("Reload already in progress".into());
+        }
+        // set flag to true and ensure it is reset on drop
+        let mut mut_guard = reloading_lock;
+        *mut_guard = true;
+        let _reset_guard = ReloadResetGuard { guard: mut_guard };
+
+        // create temporary symlink and atomically rename into place
+        std::os::unix::fs::symlink(&rel_target, &tmp_path)?;
+        tokio::fs::rename(&tmp_path, &symlink_path).await?;
+
+        // validate composed main config now that symlink points to new fragment
+        if let Err(e) = validate_cmd.validate_all().await {
+            // restore previous symlink state while still holding the guard
+            if let Some(prev) = previous_target {
+                let restore_tmp =
+                    nginx_dir.join(format!("YANPM.conf.restore.{}.{}", std::process::id(), now));
+                std::os::unix::fs::symlink(&prev, &restore_tmp)?;
+                if let Err(err) = tokio::fs::rename(&restore_tmp, &symlink_path).await {
+                    error!(
+                        "Failed to restore previous YANPM.conf symlink after validation error: {}",
+                        err
+                    );
+                }
+            } else if let Err(err) = tokio::fs::remove_file(&symlink_path).await {
+                error!(
+                    "Failed to remove YANPM.conf symlink after validation error: {}",
+                    err
+                );
+            }
+            return Err(e);
+        }
+
+        // reload the running nginx master process (no -c) so it reloads its configured main config
+        // Prefer the restricted sudo wrapper if available, fall back to direct nginx reload.
+        // TODO: allow configuring the path to the wrapper
+        match run_cmd("sudo", &["-n", "/usr/local/sbin/yanpm-nginx-reload"], 10).await {
+            Ok(res) => Ok(res),
+            Err(e) => {
+                error!(
+                    "sudo reload wrapper failed, falling back to direct nginx reload: {}",
+                    e
+                );
+                run_cmd("nginx", &["-s", "reload"], 10).await
+            }
+        }
+    }
+}

apps/agent/src/commands/run.rs

@@ -0,0 +1,85 @@
+use std::time::Duration;
+
+use tokio::{process::Command, time::timeout};
+use tracing::error;
+
+pub fn to_file_name(
+    config_name: &str,
+    timestamp: u64,
+) -> Result<String, Box<dyn std::error::Error + Send + Sync>> {
+    // reject empty or unsafe names to avoid path traversal or invalid filesystem chars
+    if config_name.is_empty() {
+        return Err("config_name is empty".into());
+    }
+    if config_name.len() > 255 {
+        return Err("config_name too long".into());
+    }
+    if config_name.contains('/') || config_name.contains('\\') || config_name.contains("..") {
+        return Err("config_name contains invalid path characters".into());
+    }
+    if !config_name
+        .chars()
+        .all(|c| c.is_ascii_alphanumeric() || "-._".contains(c))
+    {
+        return Err("config_name contains invalid characters".into());
+    }
+
+    Ok(format!("{}_{}.conf", timestamp, config_name))
+}
+
+pub async fn run_cmd(
+    cmd: &str,
+    args: &[&str],
+    dur_s: u64,
+) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+    let mut c = Command::new(cmd);
+    c.args(args);
+    let res = timeout(Duration::from_secs(dur_s), c.output()).await;
+    let out = match res {
+        Ok(Ok(out)) => out,
+        Ok(Err(e)) => return Err(Box::new(e)),
+        Err(_) => {
+            return Err(Box::new(std::io::Error::new(
+                std::io::ErrorKind::TimedOut,
+                "command timeout",
+            )));
+        }
+    };
+    let code = out.status.code().unwrap_or(-1);
+    let output = String::from_utf8_lossy(&[out.stdout, out.stderr].concat()).to_string();
+    if code != 0 {
+        error!("command failed ({}): {}", code, output);
+        return Err(format!("command failed ({}): {}", code, output).into());
+    }
+    Ok((code, output))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::to_file_name;
+
+    #[test]
+    fn to_file_name_valid() {
+        let res = to_file_name("myconf", 1234).expect("should succeed");
+        assert_eq!(res, "1234_myconf.conf");
+    }
+
+    #[test]
+    fn to_file_name_empty() {
+        assert!(to_file_name("", 1).is_err());
+    }
+
+    #[test]
+    fn to_file_name_invalid_chars() {
+        assert!(to_file_name("bad/name", 1).is_err());
+        assert!(to_file_name("bad\\name", 1).is_err());
+        assert!(to_file_name("bad..name", 1).is_err());
+        assert!(to_file_name("bad$name", 1).is_err());
+    }
+
+    #[test]
+    fn to_file_name_too_long() {
+        let long = "a".repeat(300);
+        assert!(to_file_name(&long, 1).is_err());
+    }
+}

apps/agent/src/commands/validate.rs

@@ -0,0 +1,166 @@
+use tracing::{info, warn};
+
+use crate::commands::{run::run_cmd, write_config::INTERNAL_CONFIG_FOLDER_NAME};
+use std::path::PathBuf;
+
+pub struct ValidateCommand {
+    nginx_config_dir: PathBuf,
+}
+
+impl ValidateCommand {
+    pub fn new(nginx_config_dir: PathBuf) -> Self {
+        Self { nginx_config_dir }
+    }
+
+    pub fn nginx_config_dir(&self) -> PathBuf {
+        self.nginx_config_dir.clone()
+    }
+
+    pub async fn validate_all(
+        &self,
+    ) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+        // Try a normal config test first. If it fails due to pid permission
+        // errors (common when running unprivileged against /run/nginx.pid),
+        // retry with a writable pid override so validation can succeed.
+        match run_cmd("nginx", &["-t"], 10).await {
+            Ok(res) => Ok(res),
+            Err(e) => {
+                info!(
+                    "nginx -t failed: {}. Trying with privileged wrapper or writable pid override.",
+                    e
+                );
+                let es = e.to_string();
+                if es.contains("/run/nginx.pid") && es.contains("Permission denied") {
+                    // Try privileged validate wrapper if available (allows the agent to run
+                    // nginx -t via sudo without modifying the main config).
+                    match run_cmd(
+                        "sudo",
+                        // TODO: allow configuring the path to the wrapper
+                        &["-n", "/usr/local/sbin/yanpm-nginx-validate"],
+                        10,
+                    )
+                    .await
+                    {
+                        Ok(res) => return Ok(res),
+                        Err(e) => {
+                            warn!(
+                                "Privileged validate wrapper failed: {}. Falling back to writable pid override.",
+                                e
+                            );
+                            // Fallback to the existing writable-pid override if sudo wrapper
+                            // isn't available or fails.
+                            let pid_path = format!(
+                                "{}/yanpm-validate-{}.pid",
+                                std::env::temp_dir().display(),
+                                std::process::id()
+                            );
+                            let g_arg = format!("pid {};", pid_path);
+                            let args_vec = ["-t".to_string(), "-g".to_string(), g_arg];
+                            let args_ref: Vec<&str> = args_vec.iter().map(|s| s.as_str()).collect();
+                            return run_cmd("nginx", args_ref.as_slice(), 10).await;
+                        }
+                    }
+                }
+                Err(e)
+            }
+        }
+    }
+
+    pub async fn validate(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+    ) -> Result<(i32, String), Box<dyn std::error::Error + Send + Sync>> {
+        let filename = crate::commands::run::to_file_name(config_name, timestamp)?;
+        // fragments are written into the YANPM subdirectory
+        let full_path = self
+            .nginx_config_dir
+            .join(INTERNAL_CONFIG_FOLDER_NAME)
+            .join(&filename);
+
+        // ensure the fragment file exists
+        if tokio::fs::metadata(&full_path).await.is_err() {
+            return Err(format!("Config file not found: {}", full_path.display()).into());
+        }
+
+        // Create a temporary wrapper nginx config that provides the required
+        // top-level sections (`events` and `http`) and includes the fragment.
+        let fragment_path = full_path.to_str().ok_or("invalid config path")?.to_string();
+
+        let mut tmp_path = std::env::temp_dir();
+        let tmp_name = format!("yanpm-validate-{}-{}.conf", timestamp, std::process::id());
+        tmp_path.push(tmp_name);
+
+        let wrapper = format!(
+            "worker_processes 1;\nevents {{ worker_connections 1024; }}\nhttp {{\n    include {};\n}}\n",
+            fragment_path
+        );
+
+        // Write the temporary wrapper file
+        tokio::fs::write(&tmp_path, wrapper).await?;
+        let tmp_path_str = tmp_path
+            .to_str()
+            .ok_or("invalid temp config path")?
+            .to_string();
+
+        // Run the test against the wrapper, telling nginx to place its pid
+        // somewhere writable so the config test doesn't fail with permission
+        // errors when running as an unprivileged user.
+        let result = match run_cmd("nginx", &["-t", "-c", &tmp_path_str], 10).await {
+            Ok(res) => Ok(res),
+            Err(e) => {
+                info!(
+                    "nginx -t failed: {}. Trying with privileged wrapper or writable pid override.",
+                    e
+                );
+                let es = e.to_string();
+                if es.contains("/run/nginx.pid") && es.contains("Permission denied") {
+                    // Try privileged validate wrapper if available (allows the agent to run
+                    // nginx -t via sudo without modifying the main config).
+                    match run_cmd(
+                        "sudo",
+                        // TODO: allow configuring the path to the wrapper
+                        &[
+                            "-n",
+                            "/usr/local/sbin/yanpm-nginx-validate-file",
+                            &tmp_path_str,
+                        ],
+                        10,
+                    )
+                    .await
+                    {
+                        Ok(res) => return Ok(res),
+                        Err(e) => {
+                            warn!(
+                                "Privileged validate wrapper failed: {}. Falling back to writable pid override.",
+                                e
+                            );
+                            let pid_path = format!(
+                                "{}/yanpm-validate-{}.pid",
+                                std::env::temp_dir().display(),
+                                std::process::id()
+                            );
+                            let g_arg = format!("pid {};", pid_path);
+
+                            let args_vec = [
+                                "-t".to_string(),
+                                "-c".to_string(),
+                                tmp_path_str.clone(),
+                                "-g".to_string(),
+                                g_arg,
+                            ];
+                            let args_ref: Vec<&str> = args_vec.iter().map(|s| s.as_str()).collect();
+
+                            return run_cmd("nginx", args_ref.as_slice(), 10).await;
+                        }
+                    }
+                }
+                Err(e)
+            }
+        };
+
+        let _ = tokio::fs::remove_file(&tmp_path).await;
+
+        result
+    }
+}

apps/agent/src/commands/write_config.rs

@@ -0,0 +1,133 @@
+use std::os::unix::fs::PermissionsExt;
+use std::path::PathBuf;
+use std::time::{SystemTime, UNIX_EPOCH};
+use tokio::io::AsyncWriteExt;
+use tracing::info;
+
+use crate::commands::run::to_file_name;
+
+pub const INTERNAL_CONFIG_FOLDER_NAME: &str = "YANPM";
+const FILE_SIZE_LIMIT: usize = 10 * 1024 * 1024; // 10MB
+
+pub struct WriteConfigCommand {
+    nginx_config_dir: PathBuf,
+}
+
+impl WriteConfigCommand {
+    pub fn new(nginx_config_dir: PathBuf) -> Self {
+        Self { nginx_config_dir }
+    }
+    pub async fn write_config(
+        &self,
+        config_name: &str,
+        timestamp: u64,
+        content: &str,
+    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+        let filename = to_file_name(config_name, timestamp)?;
+        let path = self.nginx_config_dir.clone();
+        // ensure main config dir exists
+        tokio::fs::create_dir_all(&path).await?;
+        info!("Writing config to {:?}", path.join(&filename));
+
+        // create YANPM subdir where fragment files live
+        let yanpm_dir = path.join(INTERNAL_CONFIG_FOLDER_NAME);
+        tokio::fs::create_dir_all(&yanpm_dir).await?;
+        let final_path = yanpm_dir.join(&filename);
+
+        // limit size to 10MB
+        if content.len() > FILE_SIZE_LIMIT {
+            return Err(format!(
+                "content exceeds {}MB size limit",
+                FILE_SIZE_LIMIT / (1024 * 1024)
+            )
+            .into());
+        }
+
+        // create a temporary filename in the same directory for atomic replace
+        let now = SystemTime::now().duration_since(UNIX_EPOCH)?.as_nanos();
+        let tmp_filename = format!("{}.tmp.{}.{}", filename, std::process::id(), now);
+        // create tmp file in the same directory as final file to ensure atomic rename
+        let tmp_path = yanpm_dir.join(tmp_filename);
+
+        let mut file = tokio::fs::OpenOptions::new()
+            .create(true)
+            .write(true)
+            .truncate(true)
+            .open(&tmp_path)
+            .await?;
+        file.write_all(content.as_bytes()).await?;
+        // ensure data is flushed to disk; propagate errors
+        file.sync_all().await?;
+
+        // atomically move the tmp file into the YANPM dir
+        tokio::fs::rename(&tmp_path, &final_path).await?;
+
+        // set explicit permissions (rw-r-----)
+        tokio::fs::set_permissions(&final_path, std::fs::Permissions::from_mode(0o640)).await?;
+        info!("Config written and permissions set for {:?}", final_path);
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{INTERNAL_CONFIG_FOLDER_NAME, WriteConfigCommand};
+    use std::time::SystemTime;
+    use std::time::UNIX_EPOCH;
+
+    #[tokio::test]
+    async fn write_config_success_and_cleanup() {
+        let base = std::env::temp_dir().join(format!(
+            "yanpm_test_{}_{}",
+            std::process::id(),
+            SystemTime::now()
+                .duration_since(UNIX_EPOCH)
+                .unwrap()
+                .as_nanos()
+        ));
+        // ensure clean
+        let _ = tokio::fs::remove_dir_all(&base).await;
+        let cmd = WriteConfigCommand::new(base.clone());
+
+        let config_name = "unittest";
+        let timestamp = 42u64;
+        let content = "hello world";
+
+        cmd.write_config(config_name, timestamp, content)
+            .await
+            .expect("write should succeed");
+
+        let filename = super::to_file_name(config_name, timestamp).unwrap();
+        let final_path = base.join(INTERNAL_CONFIG_FOLDER_NAME).join(&filename);
+        let data = tokio::fs::read_to_string(&final_path)
+            .await
+            .expect("file should exist");
+        assert_eq!(data, content);
+
+        // cleanup
+        tokio::fs::remove_dir_all(&base).await.expect("cleanup");
+    }
+
+    #[tokio::test]
+    async fn write_config_size_limit() {
+        let base = std::env::temp_dir().join(format!(
+            "yanpm_test_{}_{}",
+            std::process::id(),
+            SystemTime::now()
+                .duration_since(UNIX_EPOCH)
+                .unwrap()
+                .as_nanos()
+        ));
+        let _ = tokio::fs::remove_dir_all(&base).await;
+        let cmd = WriteConfigCommand::new(base.clone());
+
+        // exceed 10MB limit
+        let large = vec![b'a'; 10 * 1024 * 1024 + 1];
+        let large_str = String::from_utf8_lossy(&large).to_string();
+
+        let res = cmd.write_config("big", 1, &large_str).await;
+        assert!(res.is_err());
+
+        let _ = tokio::fs::remove_dir_all(&base).await;
+    }
+}

apps/agent/src/main.rs

@@ -0,0 +1,221 @@
+#![forbid(unsafe_code)]
+
+mod commands;
+mod openapi;
+mod routes;
+
+use axum::routing::get;
+use axum::{Router, routing::post};
+use clap::Parser;
+use std::os::unix::fs::PermissionsExt;
+use std::path::PathBuf;
+use std::sync::Arc;
+use tokio::net::UnixListener;
+use tracing::{error, info, warn};
+
+use crate::commands::NginxService;
+use crate::openapi::{GenerateOpenapiArgs, generate_openapi_doc};
+use crate::routes::{status, validate, validate_and_reload, write_config};
+
+const SOCK_ENV: &str = "YANPM_AGENT_SOCK";
+const SOCK_PERM_ENV: &str = "YANPM_AGENT_SOCK_PERM";
+const NGINX_CONFIG_DIR_ENV: &str = "YANPM_NGINX_CONFIG_DIR";
+const SOCK_GID_ENV: &str = "YANPM_AGENT_SOCK_GID";
+const SOCK_DEFAULT: &str = "./yanpm-agent.sock";
+const NGINX_CONFIG_DIR_DEFAULT: &str = "/etc/nginx/conf.d";
+const SOCK_PERM_DEFAULT: &str = "660";
+const SOCK_GID_DEFAULT: &str = "";
+
+/// Command line arguments
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+struct Args {
+    /// Unix socket path to bind the agent daemon to
+    #[arg(short = 's', long, default_value_t = String::from(SOCK_DEFAULT), env = SOCK_ENV)]
+    sock: String,
+
+    /// Directory where generated nginx config files will be written
+    #[arg(short = 'd', long, default_value_t = String::from(NGINX_CONFIG_DIR_DEFAULT), env = NGINX_CONFIG_DIR_ENV)]
+    nginx_config_dir: String,
+
+    /// Permissions to set on the unix socket (in octal), e.g. 660
+    #[arg(long, default_value_t = String::from(SOCK_PERM_DEFAULT), env = SOCK_PERM_ENV)]
+    sock_perm: String,
+
+    /// GID to set on the unix socket, default: current user's primary group
+    #[arg(long, default_value_t = String::from(SOCK_GID_DEFAULT), env = SOCK_GID_ENV)]
+    sock_gid: String,
+
+    #[command(subcommand)]
+    command: Option<SubCommand>,
+}
+
+#[derive(clap::Subcommand, Debug)]
+pub enum SubCommand {
+    /// Generate OpenAPI spec to file or stdout
+    GenerateOpenapi {
+        /// Output file path.
+        #[arg(short = 'o', long)]
+        output: String,
+    },
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    let subscriber = tracing_subscriber::fmt()
+        .with_max_level(tracing::Level::INFO)
+        .with_target(false)
+        .with_level(true)
+        .with_timer(tracing_subscriber::fmt::time::SystemTime)
+        .finish();
+
+    tracing::subscriber::set_global_default(subscriber)
+        .expect("Failed to set global default subscriber");
+
+    let args = Args::parse();
+
+    if let Some(cmd) = &args.command {
+        match cmd {
+            SubCommand::GenerateOpenapi { output } => {
+                generate_openapi_doc(&GenerateOpenapiArgs {
+                    output: output.clone(),
+                })
+                .await?;
+                return Ok(());
+            }
+        }
+    }
+
+    let (sock, nginx_config_dir, sock_perm, sock_gid) = get_args(&args).await?;
+
+    let path = PathBuf::from(&sock);
+    if let Some(dir) = path.parent() {
+        tokio::fs::create_dir_all(dir).await.unwrap_or_else(|err| {
+            error!(
+                "Warning: failed to create socket directory {}: {}",
+                dir.display(),
+                err
+            )
+        });
+        // permissive; set tighter perms in production via image/build steps
+        tokio::fs::set_permissions(dir, std::fs::Permissions::from_mode(0o770))
+            .await
+            .unwrap_or_else(|err| {
+                error!(
+                    "Warning: failed to set permissions on socket directory {}: {}",
+                    dir.display(),
+                    err
+                )
+            });
+    }
+    // If an existing path exists at the socket location, ensure it's a socket
+    match tokio::fs::metadata(&path).await {
+        Ok(md) => {
+            use std::os::unix::fs::FileTypeExt;
+            if md.file_type().is_socket() {
+                tokio::fs::remove_file(&path).await.unwrap_or_else(|err| {
+                    error!(
+                        "Warning: failed to remove existing socket file {}: {}",
+                        path.display(),
+                        err
+                    )
+                });
+            } else {
+                return Err(
+                    format!("Socket path {} exists and is not a socket", path.display()).into(),
+                );
+            }
+        }
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {}
+        Err(e) => {
+            return Err(format!("Failed to stat socket path {}: {}", path.display(), e).into());
+        }
+    }
+
+    // bind using tokio's UnixListener (avoids converting a blocking std listener)
+    let listener = UnixListener::bind(&path).expect("Failed to bind to unix socket");
+    // set socket perms to sock_perm (best-effort)
+    if let Err(err) =
+        tokio::fs::set_permissions(&path, std::fs::Permissions::from_mode(sock_perm)).await
+    {
+        error!(
+            "Warning: failed to set permissions on socket {}: {}",
+            path.display(),
+            err
+        );
+    }
+
+    // set socket gid to sock_gid (best-effort)
+    if !sock_gid.is_empty() {
+        use nix::unistd::{Gid, chown};
+        if let Err(err) = chown(
+            &path,
+            None,
+            Some(Gid::from_raw(
+                sock_gid
+                    .parse()
+                    .map_err(|e| format!("Failed to parse socket GID {}: {}", sock_gid, e))
+                    .unwrap_or_else(|_| nix::unistd::getgid().as_raw()),
+            )),
+        ) {
+            error!(
+                "Warning: failed to set GID on socket {}: {}",
+                path.display(),
+                err
+            );
+        }
+    }
+
+    let scheduler = Arc::new(tokio_cron_scheduler::JobScheduler::new().await?);
+
+    let app = Router::new()
+        .route("/status", get(status))
+        .route("/validate_and_reload", post(validate_and_reload))
+        .route("/validate", post(validate))
+        .route("/write_config", post(write_config))
+        .with_state(NginxService::new(scheduler.clone(), PathBuf::from(nginx_config_dir)).await?);
+
+    scheduler.clone().start().await?;
+
+    info!("Starting yanpm-daemon on unix socket: {}", sock);
+    axum::serve::serve(listener, app)
+        .await
+        .expect("Failed to start axum server");
+
+    info!("Shutting down yanpm-daemon");
+    Ok(())
+}
+
+async fn get_args(
+    args: &Args,
+) -> Result<(String, String, u32, String), Box<dyn std::error::Error + Send + Sync>> {
+    let sock = args.sock.clone();
+    let nginx_config_dir = args.nginx_config_dir.clone();
+    let sock_perm = args.sock_perm.clone();
+    let sock_gid = args.sock_gid.clone();
+
+    if sock_perm.len() != 3 || !sock_perm.chars().all(|c| ('0'..='7').contains(&c)) {
+        return Err(std::io::Error::new(
+            std::io::ErrorKind::InvalidInput,
+            format!(
+                "Invalid socket permission string: {}. Must be a 3-digit octal number.",
+                sock_perm
+            ),
+        )
+        .into());
+    }
+
+    if sock_perm.chars().last().unwrap() > '0' {
+        warn!(
+            "Socket permission string {} allows others to access the socket. This may be a security risk. Consider setting {} to a desired group and using a socket permission string that does not allow others to access the socket.",
+            sock_perm, SOCK_GID_ENV
+        );
+    };
+
+    Ok((
+        sock,
+        nginx_config_dir,
+        u32::from_str_radix(&sock_perm, 8).expect("Failed to parse socket permission string"),
+        sock_gid,
+    ))
+}

apps/agent/src/openapi.rs

@@ -0,0 +1,45 @@
+use tracing::info;
+use utoipa::OpenApi;
+
+pub mod tag {
+    /// nginx
+    pub const NGINX_TAG: &str = "Nginx Agent";
+}
+
+#[derive(utoipa::OpenApi)]
+#[openapi(
+  paths(
+    crate::routes::status,
+    crate::routes::validate,
+    crate::routes::validate_and_reload,
+    crate::routes::write_config,
+  ),
+  components(
+      schemas(crate::routes::StatusResp),
+      schemas(crate::routes::ValidateAndReloadResp),
+      schemas(crate::routes::ValidateBody),
+      schemas(crate::routes::WriteConfigBody),
+      schemas(crate::routes::ValidateAndReloadBody),
+  ),
+  tags(
+      (name = tag::NGINX_TAG, description = "Nginx Agent API"),
+  )
+)]
+struct ApiDoc;
+
+pub struct GenerateOpenapiArgs {
+    pub output: String,
+}
+
+pub async fn generate_openapi_doc(
+    args: &GenerateOpenapiArgs,
+) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
+    info!("Generating OpenAPI documentation...");
+    let doc = ApiDoc::openapi();
+    let json = doc
+        .to_pretty_json()
+        .expect("Failed to serialize OpenAPI doc to JSON");
+    std::fs::write(&args.output, json).expect("Failed to write OpenAPI doc to file");
+    info!("OpenAPI documentation generated at {}", args.output);
+    Ok(())
+}

apps/agent/src/routes.rs

@@ -0,0 +1,167 @@
+use axum::Json;
+use axum::extract::State;
+use axum::http::StatusCode;
+use axum::response::IntoResponse;
+use serde::{Deserialize, Serialize};
+use serde_json::{Value, from_value};
+use std::sync::Arc;
+use tracing::warn;
+
+use crate::commands::NginxService;
+
+#[derive(Serialize, utoipa::ToSchema)]
+pub struct StatusResp {
+    pub ok: bool,
+}
+
+/// Health check endpoint
+#[utoipa::path(
+    get,
+    path = "/status",
+    responses(
+        (status = 200, description = "Status response", body = StatusResp)
+    ),
+    tag = crate::openapi::tag::NGINX_TAG
+)]
+pub async fn status() -> impl IntoResponse {
+    let resp = StatusResp { ok: true };
+    (axum::http::StatusCode::OK, axum::Json(resp))
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+pub struct ValidateAndReloadResp {
+    pub rc: i32,
+    pub ro: String,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+pub struct ValidateBody {
+    config_name: String,
+    timestamp: u64,
+}
+
+#[utoipa::path(
+    post,
+    path = "/validate",
+    request_body = ValidateBody,
+    responses(
+        (status = 200, description = "Validation response", body = serde_json::Value)
+    ),
+    tag = crate::openapi::tag::NGINX_TAG
+)]
+pub async fn validate(
+    State(nginx_controller): State<Arc<NginxService>>,
+    Json(payload): Json<Value>,
+) -> impl IntoResponse {
+    let params: ValidateBody = match from_value(payload) {
+        Ok(req) => req,
+        Err(e) => {
+            warn!("Invalid validate request: {}", e);
+            return (StatusCode::BAD_REQUEST).into_response();
+        }
+    };
+
+    let resp = match nginx_controller
+        .validate(&params.config_name, params.timestamp)
+        .await
+    {
+        Ok(res) => res,
+        Err(e) => {
+            let resp = serde_json::json!({ "error": e.to_string() });
+            return (StatusCode::INTERNAL_SERVER_ERROR, axum::Json(resp)).into_response();
+        }
+    };
+
+    (axum::http::StatusCode::OK, axum::Json(resp)).into_response()
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+pub struct ValidateAndReloadBody {
+    config_name: String,
+    timestamp: u64,
+}
+
+#[utoipa::path(
+    post,
+    path = "/validate_and_reload",
+    request_body = ValidateAndReloadBody,
+    responses(
+        (status = 200, description = "Validate and reload response", body = ValidateAndReloadResp)
+    ),
+    tag = crate::openapi::tag::NGINX_TAG
+)]
+pub async fn validate_and_reload(
+    State(nginx_controller): State<Arc<NginxService>>,
+    Json(payload): Json<Value>,
+) -> impl IntoResponse {
+    let params: ValidateAndReloadBody = match from_value(payload) {
+        Ok(req) => req,
+        Err(e) => {
+            warn!("Invalid validate_and_reload request: {}", e);
+            return (StatusCode::BAD_REQUEST).into_response();
+        }
+    };
+
+    let (code, output) = match nginx_controller
+        .validate_and_reload(&params.config_name, params.timestamp)
+        .await
+    {
+        Ok(res) => res,
+        Err(e) => {
+            let resp = ValidateAndReloadResp {
+                rc: -1,
+                ro: e.to_string(),
+            };
+            return (StatusCode::INTERNAL_SERVER_ERROR, axum::Json(resp)).into_response();
+        }
+    };
+
+    let resp = ValidateAndReloadResp {
+        rc: code,
+        ro: output,
+    };
+    (axum::http::StatusCode::OK, axum::Json(resp)).into_response()
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+pub struct WriteConfigBody {
+    config_name: String,
+    timestamp: u64,
+    content: String,
+}
+
+#[utoipa::path(
+    post,
+    path = "/write_config",
+    request_body = WriteConfigBody,
+    responses(
+        (status = 200, description = "Write config response"),
+        (status = 500, description = "Internal server error", body = serde_json::Value)
+    ),
+    tag = crate::openapi::tag::NGINX_TAG
+)]
+pub async fn write_config(
+    State(nginx_controller): State<Arc<NginxService>>,
+    Json(payload): Json<Value>,
+) -> impl IntoResponse {
+    let body: WriteConfigBody = match from_value(payload) {
+        Ok(req) => req,
+        Err(e) => {
+            warn!("Invalid write_config request: {}", e);
+            return (StatusCode::BAD_REQUEST).into_response();
+        }
+    };
+
+    match nginx_controller
+        .write_config(&body.config_name, body.timestamp, &body.content)
+        .await
+    {
+        Ok(_) => (),
+        Err(e) => {
+            let resp = serde_json::json!({ "error": e.to_string() });
+            return (StatusCode::INTERNAL_SERVER_ERROR, axum::Json(resp)).into_response();
+        }
+    };
+
+    (axum::http::StatusCode::OK,).into_response()
+}

apps/agent/swagger.json

@@ -0,0 +1,215 @@
+{
+  "openapi": "3.1.0",
+  "info": {
+    "title": "yanpm-agent",
+    "description": "",
+    "license": {
+      "name": ""
+    },
+    "version": "0.1.0"
+  },
+  "paths": {
+    "/status": {
+      "get": {
+        "tags": [
+          "Nginx Agent"
+        ],
+        "summary": "Health check endpoint",
+        "operationId": "status",
+        "responses": {
+          "200": {
+            "description": "Status response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/StatusResp"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/validate": {
+      "post": {
+        "tags": [
+          "Nginx Agent"
+        ],
+        "operationId": "validate",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/ValidateBody"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "Validation response",
+            "content": {
+              "application/json": {
+                "schema": {}
+              }
+            }
+          }
+        }
+      }
+    },
+    "/validate_and_reload": {
+      "post": {
+        "tags": [
+          "Nginx Agent"
+        ],
+        "operationId": "validate_and_reload",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/ValidateAndReloadBody"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "Validate and reload response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/ValidateAndReloadResp"
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/write_config": {
+      "post": {
+        "tags": [
+          "Nginx Agent"
+        ],
+        "operationId": "write_config",
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/WriteConfigBody"
+              }
+            }
+          },
+          "required": true
+        },
+        "responses": {
+          "200": {
+            "description": "Write config response"
+          },
+          "500": {
+            "description": "Internal server error",
+            "content": {
+              "application/json": {
+                "schema": {}
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components": {
+    "schemas": {
+      "StatusResp": {
+        "type": "object",
+        "required": [
+          "ok"
+        ],
+        "properties": {
+          "ok": {
+            "type": "boolean"
+          }
+        }
+      },
+      "ValidateAndReloadBody": {
+        "type": "object",
+        "required": [
+          "config_name",
+          "timestamp"
+        ],
+        "properties": {
+          "config_name": {
+            "type": "string"
+          },
+          "timestamp": {
+            "type": "integer",
+            "format": "int64",
+            "minimum": 0
+          }
+        }
+      },
+      "ValidateAndReloadResp": {
+        "type": "object",
+        "required": [
+          "rc",
+          "ro"
+        ],
+        "properties": {
+          "rc": {
+            "type": "integer",
+            "format": "int32"
+          },
+          "ro": {
+            "type": "string"
+          }
+        }
+      },
+      "ValidateBody": {
+        "type": "object",
+        "required": [
+          "config_name",
+          "timestamp"
+        ],
+        "properties": {
+          "config_name": {
+            "type": "string"
+          },
+          "timestamp": {
+            "type": "integer",
+            "format": "int64",
+            "minimum": 0
+          }
+        }
+      },
+      "WriteConfigBody": {
+        "type": "object",
+        "required": [
+          "config_name",
+          "timestamp",
+          "content"
+        ],
+        "properties": {
+          "config_name": {
+            "type": "string"
+          },
+          "content": {
+            "type": "string"
+          },
+          "timestamp": {
+            "type": "integer",
+            "format": "int64",
+            "minimum": 0
+          }
+        }
+      }
+    }
+  },
+  "tags": [
+    {
+      "name": "Nginx Agent",
+      "description": "Nginx Agent API"
+    }
+  ]
+}

apps/api/Cargo.toml

@@ -6,8 +6,10 @@ edition = "2024"
 [dependencies]
 database = { path = "../../public/database" }
 migration = { path = "../../public/migration" }
+agent_client = { path = "../../public/agent-client" }
 
-axum = { version = "0.8.7", features = ["form", "http1", "http2", "json", "matched-path", "original-uri", "query", "tokio", "tower-log", "tracing", "macros"]}
+axum = { version = "0.8.7", features = ["form", "http1", "http2", "json", "matched-path", "original-uri", "query", "tokio", "tower-log", "tracing", "macros"] }
+axum-extra = { version = "0.12.2", features = ["cookie"] }
 async-trait = { version = "0.1.89" }
 chrono = { version = "0.4.42", features = ["clock", "std", "oldtime", "wasmbind", "serde"] }
 config = { version = "0.15.19", features = ["toml", "json", "yaml", "ini", "ron", "json5", "convert-case", "async"] }
@@ -23,3 +25,18 @@ mime_guess = { version = "2.0.5" }
 utoipa = { version = "5.4.0", features = ["macros", "axum_extras", "chrono", "decimal", "uuid", "time", "openapi_extensions"] }
 clap = { version = "4.5.53" }
 once_cell = { version = "1.21.3" }
+argon2 = { version = "0.5.3", features = ["std"] }
+jsonwebtoken = { version = "10.2.0", features = ["rust_crypto"] }
+uuid = { version = "1.19.0", features = ["v4", "serde", "fast-rng"] }
+tower-http = { version = "0.6.8", features = ["cors"] }
+reqwest = { version = "^0.12", features = ["json", "multipart", "stream"] }
+serde_urlencoded = { version = "0.7.1" }
+
+[dev-dependencies]
+tempfile = "3"
+axum-test = "18.4.1"
+agent_client = { path = "../../public/agent-client", features = ["mockall"] }
+mockall = { version = "0.14.0", features = [] }
+
+[lints.clippy]
+unwrap_used = "deny"

apps/api/src/cmd/generate_openapi.rs

@@ -28,7 +28,7 @@ fn action(
     _matches: &clap::ArgMatches,
 ) -> std::pin::Pin<Box<dyn std::future::Future<Output = ()> + Send>> {
     let output_path = _matches.get_one::<String>("output_path");
-    let output_path = output_path.unwrap().to_string();
+    let output_path = output_path.expect("output_path is required").to_string();
 
     Box::pin(async move {
         tracing::subscriber::with_default(log::make_temporary_subscriber(), || {

apps/api/src/cmd/start_server.rs

@@ -11,8 +11,8 @@ use crate::{
     cmd::CliCommand,
     configs::{ProgramSettings, get_program_settings, logging::LoggingSettings},
     log,
-    routes::{self, AppService, AppState},
-    services::settings::SettingsService,
+    routes::{self, AppState},
+    services::get_app_service,
     tasks,
 };
 
@@ -58,6 +58,9 @@ pub async fn start_server() {
 
     tasks::startup::run_startup_tasks(&settings)
         .await
+        .inspect_err(|err| {
+            tracing::error!("Failed to run startup tasks: {}", err);
+        })
         .expect("Failed to run startup tasks");
 
     // setup database connection pool
@@ -78,7 +81,23 @@ pub async fn start_server() {
 
     // build the axum app and run the server...
     info!("Starting application...");
-    let app: Router = routes::get_root_router(Arc::new(get_app_state(&db_connection)));
+    let mut app: Router = routes::get_root_router(
+        Arc::new(get_app_state(&db_connection, &settings)),
+        Arc::new(settings.server.cors.clone()),
+    );
+
+    if settings.server.serve_openapi {
+        info!("Enabling OpenAPI documentation endpoint at /openapi.json");
+        app = app.route(
+            "/openapi.json",
+            axum::routing::get(|| async {
+                use utoipa::OpenApi;
+                let doc = routes::ApiDoc::openapi();
+                doc.to_pretty_json()
+                    .expect("Failed to serialize OpenAPI doc to JSON")
+            }),
+        );
+    }
 
     let address = format!("{}:{}", settings.server.address, settings.server.port);
     info!("Starting server at http://{}", address);
@@ -115,12 +134,14 @@ fn get_global_tracing_subscriber_builder(
     }
 }
 
-fn get_app_state(db_connection: &Arc<sea_orm::DatabaseConnection>) -> AppState {
+fn get_app_state(
+    db_connection: &Arc<sea_orm::DatabaseConnection>,
+    settings: &ProgramSettings,
+) -> AppState {
     AppState {
         database_connection: db_connection.clone(),
-        service: Arc::new(AppService {
-            settings: Arc::new(SettingsService::new(db_connection.clone())),
-        }),
+        config: Arc::new(settings.clone()),
+        service: Arc::new(get_app_service(db_connection, settings)),
     }
 }
 

apps/api/src/configs.rs

@@ -1,3 +1,5 @@
+pub mod agent;
+pub mod auth;
 pub mod database;
 pub mod logging;
 pub mod server;
@@ -10,6 +12,8 @@ use tracing::{debug, error};
 pub trait FromConfig: Sized {
     fn from_config(config: &Config) -> Result<Self, String>;
     fn validate(&self) -> Result<(), String>;
+    #[cfg(test)]
+    fn mock() -> Self;
 }
 
 #[derive(Debug, Clone)]
@@ -17,6 +21,8 @@ pub struct ProgramSettings {
     pub logging: logging::LoggingSettings,
     pub database: database::DatabaseSettings,
     pub server: server::ServerSettings,
+    pub auth: auth::AuthSettings,
+    pub agent: agent::AgentSettings,
 }
 
 impl FromConfig for ProgramSettings {
@@ -25,6 +31,8 @@ impl FromConfig for ProgramSettings {
             logging: logging::LoggingSettings::from_config(_config)?,
             database: database::DatabaseSettings::from_config(_config)?,
             server: server::ServerSettings::from_config(_config)?,
+            auth: auth::AuthSettings::from_config(_config)?,
+            agent: agent::AgentSettings::from_config(_config)?,
         };
         config.validate()?;
         Ok(config)
@@ -34,8 +42,20 @@ impl FromConfig for ProgramSettings {
         self.logging.validate()?;
         self.database.validate()?;
         self.server.validate()?;
+        self.auth.validate()?;
         Ok(())
     }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        ProgramSettings {
+            logging: logging::LoggingSettings::mock(),
+            database: database::DatabaseSettings::mock(),
+            server: server::ServerSettings::mock(),
+            auth: auth::AuthSettings::mock(),
+            agent: agent::AgentSettings::mock(),
+        }
+    }
 }
 
 pub fn get_program_settings() -> ProgramSettings {

apps/api/src/configs/agent.rs

@@ -0,0 +1,58 @@
+use config::Config;
+use tracing::error;
+
+use crate::configs::key::AGENT_SOCK_PATH_KEY;
+
+use super::FromConfig;
+
+#[derive(Debug, Clone)]
+pub struct AgentSettings {
+    pub socket_path: String,
+}
+
+impl FromConfig for AgentSettings {
+    fn from_config(_config: &Config) -> Result<Self, String> {
+        Ok(AgentSettings {
+            socket_path: _config.get_string(AGENT_SOCK_PATH_KEY).map_err(|err| {
+                format!(
+                    "Failed to get {} from configuration. Err: {}",
+                    AGENT_SOCK_PATH_KEY, err
+                )
+            })?,
+        })
+    }
+
+    fn validate(&self) -> Result<(), String> {
+        // ensure socket_path exists and is readable and writable
+        if !std::path::Path::new(&self.socket_path).exists() {
+            let msg = format!("Agent socket path '{}' does not exist", self.socket_path);
+            error!("{}", msg);
+            return Err(msg);
+        }
+        if std::path::Path::new(&self.socket_path)
+            .metadata()
+            .map(|meta| {
+                let permissions = meta.permissions();
+                // Check read and write permissions for the owner
+                !permissions.readonly()
+            })
+            .unwrap_or(false)
+        {
+            Ok(())
+        } else {
+            let msg = format!(
+                "Agent socket path '{}' is not readable/writable",
+                self.socket_path
+            );
+            error!("{}", msg);
+            Err(msg)
+        }
+    }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        AgentSettings {
+            socket_path: "/tmp/agent.sock".to_string(),
+        }
+    }
+}

apps/api/src/configs/auth.rs

@@ -0,0 +1,60 @@
+use config::{Config, ConfigError};
+use tracing::warn;
+
+use crate::configs::key::{
+    AUTH_DEFAULT_ADMIN_PASSWORD_KEY, AUTH_DEFAULT_ADMIN_USERNAME_KEY, AUTH_JWT_SECRET_KEY,
+};
+
+use super::FromConfig;
+
+#[derive(Debug, Clone)]
+pub struct AuthSettings {
+    pub jwt_secret: Option<String>,
+    pub default_admin_username: Option<String>,
+    pub default_admin_password: Option<String>,
+}
+
+impl FromConfig for AuthSettings {
+    fn from_config(_config: &Config) -> Result<Self, String> {
+        Ok(AuthSettings {
+            jwt_secret: _config
+                .get_string(AUTH_JWT_SECRET_KEY)
+                .inspect_err(|err| {
+                    match err {
+                        ConfigError::NotFound(_) => {
+                            warn!(
+                                "{} not found in configuration, A random secret will be generated at runtime.",
+                                AUTH_JWT_SECRET_KEY
+                            );
+                        }
+                        _ => {
+                            warn!(
+                                "Failed to read {} from configuration, A random secret will be generated at runtime: {}",
+                                AUTH_JWT_SECRET_KEY, err
+                            );
+                        }
+                    };
+                })
+                .ok(),
+            default_admin_username: _config
+                .get_string(AUTH_DEFAULT_ADMIN_USERNAME_KEY)
+                .ok(),
+            default_admin_password: _config
+                .get_string(AUTH_DEFAULT_ADMIN_PASSWORD_KEY)
+                .ok(),
+        })
+    }
+
+    fn validate(&self) -> Result<(), String> {
+        Ok(())
+    }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        AuthSettings {
+            jwt_secret: Some("mock_jwt_secret".to_string()),
+            default_admin_username: Some("admin".to_string()),
+            default_admin_password: Some("password".to_string()),
+        }
+    }
+}

apps/api/src/configs/database.rs

@@ -50,4 +50,13 @@ impl FromConfig for DatabaseSettings {
     fn validate(&self) -> Result<(), String> {
         Ok(())
     }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        DatabaseSettings {
+            url: "sqlite::memory:".to_string(),
+            max_connections: 5,
+            migrate_on_startup: true,
+        }
+    }
 }

apps/api/src/configs/key.rs

@@ -3,7 +3,16 @@ pub(crate) const LOGGING_UTC_KEY: &str = "LOGGING.UTC";
 //
 pub(crate) const SERVER_ADDRESS_KEY: &str = "SERVER.ADDRESS";
 pub(crate) const SERVER_PORT_KEY: &str = "SERVER.PORT";
+pub(crate) const SERVER_SERVE_OPENAPI_KEY: &str = "SERVER.SERVE_OPENAPI";
+pub(crate) const SERVER_CORS_ALLOWED_ORIGINS_KEY: &str = "SERVER.CORS.ALLOWED_ORIGINS";
+pub(crate) const SERVER_COOKIES_SECURE_KEY: &str = "SERVER.COOKIES.SECURE";
 //
 pub(crate) const DATABASE_URL_KEY: &str = "DATABASE.URL";
 pub(crate) const DATABASE_MAX_CONNECTIONS_KEY: &str = "DATABASE.MAX_CONNECTIONS";
 pub(crate) const DATABASE_MIGRATE_ON_STARTUP_KEY: &str = "DATABASE.MIGRATION.MIGRATE_ON_STARTUP";
+//
+pub(crate) const AUTH_JWT_SECRET_KEY: &str = "AUTH.JWT_SECRET";
+pub(crate) const AUTH_DEFAULT_ADMIN_USERNAME_KEY: &str = "AUTH.DEFAULT_ADMIN_USERNAME";
+pub(crate) const AUTH_DEFAULT_ADMIN_PASSWORD_KEY: &str = "AUTH.DEFAULT_ADMIN_PASSWORD";
+//
+pub(crate) const AGENT_SOCK_PATH_KEY: &str = "AGENT.SOCK.PATH";

apps/api/src/configs/logging.rs

@@ -49,4 +49,12 @@ impl FromConfig for LoggingSettings {
     fn validate(&self) -> Result<(), String> {
         Ok(())
     }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        LoggingSettings {
+            level: Level::INFO,
+            utc: false,
+        }
+    }
 }

apps/api/src/configs/server.rs

@@ -3,6 +3,10 @@ use std::net::IpAddr;
 use config::{Config, ConfigError};
 use tracing::warn;
 
+use crate::configs::key::{
+    SERVER_COOKIES_SECURE_KEY, SERVER_CORS_ALLOWED_ORIGINS_KEY, SERVER_SERVE_OPENAPI_KEY,
+};
+
 use super::{
     FromConfig,
     key::{SERVER_ADDRESS_KEY, SERVER_PORT_KEY},
@@ -12,6 +16,19 @@ use super::{
 pub struct ServerSettings {
     pub address: IpAddr,
     pub port: u16,
+    pub serve_openapi: bool,
+    pub cors: CORSSettings,
+    pub cookies: CookiesSettings,
+}
+
+#[derive(Debug, Clone)]
+pub struct CORSSettings {
+    pub allowed_origins: Vec<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct CookiesSettings {
+    pub secure: bool,
 }
 
 impl FromConfig for ServerSettings {
@@ -43,6 +60,53 @@ impl FromConfig for ServerSettings {
                 );
                 DEFAULT_PORT
             }) as u16,
+
+            serve_openapi: _config
+                .get_bool(SERVER_SERVE_OPENAPI_KEY)
+                .unwrap_or_else(|err| {
+                    const DEFAULT_SERVE_OPENAPI: bool = false;
+                    warn!(
+                        "{} not set or invalid in configuration, defaulting to {}. Error: {}",
+                        SERVER_SERVE_OPENAPI_KEY, DEFAULT_SERVE_OPENAPI, err
+                    );
+                    DEFAULT_SERVE_OPENAPI
+                }),
+
+            cors: CORSSettings {
+                allowed_origins: _config
+                    .get_array(SERVER_CORS_ALLOWED_ORIGINS_KEY)
+                    .unwrap_or_else(|_| vec![])
+                    .into_iter()
+                    .filter_map(|val| match val.into_string() {
+                        Ok(s) => Some(s),
+                        Err(e) => {
+                            warn!(
+                                "Invalid origin in {} configuration: {}",
+                                SERVER_CORS_ALLOWED_ORIGINS_KEY, e
+                            );
+                            None
+                        }
+                    })
+                    .collect(),
+            },
+
+            cookies: CookiesSettings {
+                secure: _config
+                    .get_bool(SERVER_COOKIES_SECURE_KEY)
+                    .inspect(|is_secure| {
+                        if !*is_secure {
+                            warn!("Cookie 'secure' flag is disabled; this is not recommended in production environments.");
+                        }
+                    })
+                    .unwrap_or_else(|err| {
+                        const DEFAULT_COOKIES_SECURE: bool = true;
+                        warn!(
+                            "{} not set or invalid in configuration, defaulting to {}. Error: {}",
+                            SERVER_COOKIES_SECURE_KEY, DEFAULT_COOKIES_SECURE, err
+                        );
+                        DEFAULT_COOKIES_SECURE
+                    }),
+            },
         })
     }
 
@@ -53,4 +117,17 @@ impl FromConfig for ServerSettings {
         }
         Ok(())
     }
+
+    #[cfg(test)]
+    fn mock() -> Self {
+        ServerSettings {
+            address: "0.0.0.0".parse().expect("Failed to parse mock IP address"),
+            port: 8080,
+            serve_openapi: false,
+            cors: CORSSettings {
+                allowed_origins: vec![],
+            },
+            cookies: CookiesSettings { secure: true },
+        }
+    }
 }

apps/api/src/errors.rs

@@ -1 +1,2 @@
+pub mod api_error;
 pub mod service_error;

apps/api/src/errors/api_error.rs

@@ -0,0 +1,32 @@
+use axum::response::IntoResponse;
+use sea_orm::DbErr;
+use tracing::error;
+
+use crate::errors::service_error::ServiceError;
+
+#[derive(Debug)]
+pub enum ApiError {
+    ServiceError(ServiceError),
+}
+
+impl From<ServiceError> for ApiError {
+    fn from(err: ServiceError) -> Self {
+        error!("Service error occurred: {:?}", err);
+        ApiError::ServiceError(err)
+    }
+}
+
+impl From<DbErr> for ApiError {
+    fn from(err: DbErr) -> Self {
+        ServiceError::from(err).into()
+    }
+}
+
+impl IntoResponse for ApiError {
+    fn into_response(self) -> axum::response::Response {
+        error!("API error occurred: {:?}", self);
+        match self {
+            ApiError::ServiceError(service_error) => service_error.into_response(),
+        }
+    }
+}

apps/api/src/errors/service_error.rs

@@ -1,15 +1,60 @@
-pub type ServiceError = Box<dyn std::error::Error + Send + Sync>;
+use axum::response::IntoResponse;
+use sea_orm::DbErr;
 
-#[allow(dead_code)] // TODO: remove when used
-pub trait IntoServiceError {
-    fn into_service_error(self) -> ServiceError;
+#[derive(Debug)]
+pub enum ServiceError {
+    NotFound(String),
+    DatabaseError(String),
+    Unauthorized(String),
+    InternalError(String),
+    BadRequest(String),
 }
 
-impl<T> IntoServiceError for T
-where
-    T: std::error::Error + Send + Sync + 'static,
-{
-    fn into_service_error(self) -> ServiceError {
-        Box::new(self)
+impl From<Box<dyn std::error::Error + Send + Sync + 'static>> for ServiceError {
+    fn from(err: Box<dyn std::error::Error + Send + Sync + 'static>) -> Self {
+        ServiceError::InternalError(err.to_string())
+    }
+}
+
+impl std::fmt::Display for ServiceError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ServiceError::NotFound(msg) => write!(f, "Not Found: {}", msg),
+            ServiceError::DatabaseError(msg) => write!(f, "Database Error: {}", msg),
+            ServiceError::Unauthorized(msg) => write!(f, "Unauthorized: {}", msg),
+            ServiceError::InternalError(msg) => write!(f, "Internal Error: {}", msg),
+            ServiceError::BadRequest(msg) => write!(f, "Bad Request: {}", msg),
+        }
+    }
+}
+
+impl std::error::Error for ServiceError {}
+
+impl From<DbErr> for ServiceError {
+    fn from(err: DbErr) -> Self {
+        match err {
+            DbErr::RecordNotFound(msg) => ServiceError::NotFound(msg),
+            _ => ServiceError::DatabaseError(err.to_string()),
+        }
+    }
+}
+
+impl IntoResponse for ServiceError {
+    fn into_response(self) -> axum::response::Response {
+        let (status, message) = match &self {
+            ServiceError::NotFound(msg) => (axum::http::StatusCode::NOT_FOUND, msg.clone()),
+            ServiceError::DatabaseError(msg) => {
+                (axum::http::StatusCode::INTERNAL_SERVER_ERROR, msg.clone())
+            }
+            ServiceError::Unauthorized(msg) => (axum::http::StatusCode::UNAUTHORIZED, msg.clone()),
+            ServiceError::InternalError(msg) => {
+                (axum::http::StatusCode::INTERNAL_SERVER_ERROR, msg.clone())
+            }
+            ServiceError::BadRequest(msg) => (axum::http::StatusCode::BAD_REQUEST, msg.clone()),
+        };
+        let body = axum::Json(serde_json::json!({
+            "error": message,
+        }));
+        (status, body).into_response()
     }
 }

apps/api/src/helpers.rs

@@ -0,0 +1,3 @@
+pub mod constants;
+pub mod database;
+pub mod macros;

apps/api/src/helpers/constants.rs

@@ -0,0 +1,3 @@
+pub const ADMIN_INIT_SECRET_KEY: &str = "admin_init_secret";
+//
+pub const JWT_COOKIE_NAME: &str = "session_jwt";

apps/api/src/helpers/database.rs

@@ -0,0 +1,26 @@
+#[macro_export]
+macro_rules! with_conn {
+    // Usage: with_conn!(&connection, tx_option, ident, |conn|-> { ... })
+    ($conn:expr, $tx:expr, $ident:ident, $body:block) => {{
+        if let Some(t) = &$tx {
+            let $ident = t;
+            $body
+        } else {
+            let $ident = &$conn;
+            $body
+        }
+    }};
+}
+
+pub struct PaginationFilter {
+    pub page: u64,
+    pub per_page: u64,
+}
+
+impl PaginationFilter {
+    pub fn get_offset_limit(&self) -> (u64, u64) {
+        let offset = (self.page - 1) * self.per_page;
+        let limit = self.per_page;
+        (offset, limit)
+    }
+}

apps/api/src/helpers/macros.rs

@@ -0,0 +1,9 @@
+#[macro_export]
+macro_rules! set_if_some {
+    ($field:expr) => {
+        match $field {
+            Some(value) => sea_orm::ActiveValue::Set(value),
+            None => sea_orm::ActiveValue::NotSet,
+        }
+    };
+}

apps/api/src/main.rs

@@ -1,6 +1,9 @@
+#![forbid(unsafe_code)]
+
 mod cmd;
 mod configs;
 mod errors;
+mod helpers;
 mod log;
 mod middlewares;
 mod routes;

apps/api/src/middlewares.rs

@@ -1,25 +1,61 @@
+pub mod request_info;
+pub mod require_auth;
+
+use std::{sync::Arc, time::Duration};
+
 use axum::{
     BoxError, Router,
     error_handling::HandleErrorLayer,
-    http::{Method, StatusCode, Uri},
+    http::{HeaderValue, Method, StatusCode, Uri},
 };
-use std::time::Duration;
 use tower::{ServiceBuilder, timeout::TimeoutLayer};
-
+use tower_http::cors::{AllowHeaders, AllowMethods, AllowOrigin, CorsLayer};
 use tracing::warn;
 
+use crate::{configs::server::CORSSettings, routes::AppState};
+
 pub const TIMEOUT_DURATION_SECS: u64 = 30;
 
-pub fn apply_root_middleware(router: Router) -> Router {
+pub fn apply_root_middleware(
+    router: Router,
+    _state: Arc<AppState>,
+    cors_settings: Arc<CORSSettings>,
+) -> Router {
     let timeout_layer = TimeoutLayer::new(Duration::from_secs(TIMEOUT_DURATION_SECS));
 
     let service_builder = ServiceBuilder::new()
         .layer(HandleErrorLayer::new(handle_timeout_error))
-        .layer(timeout_layer);
+        .layer(timeout_layer)
+        .layer(get_cors_layer(cors_settings));
 
     router.layer(service_builder)
 }
 
+pub fn get_cors_layer(cors_settings: Arc<CORSSettings>) -> CorsLayer {
+    let mut cors_layer = CorsLayer::new()
+        .allow_credentials(true)
+        .allow_methods(AllowMethods::mirror_request())
+        .allow_headers(AllowHeaders::mirror_request());
+
+    let allowed_origins = &cors_settings.allowed_origins;
+    if allowed_origins.contains(&"*".to_string()) {
+        cors_layer = cors_layer.allow_origin(AllowOrigin::mirror_request());
+        warn!(
+            "Wildcard origin is found in allowed origins. CORS is configured to allow requests from any origin. Only use this setting in development or if you understand the security implications."
+        );
+    } else {
+        for origin in allowed_origins {
+            if let Ok(header_value) = HeaderValue::from_str(origin) {
+                cors_layer = cors_layer.allow_origin(AllowOrigin::exact(header_value));
+            } else {
+                warn!("Invalid CORS origin: {}", origin);
+            }
+        }
+    }
+
+    cors_layer
+}
+
 pub async fn handle_timeout_error(
     method: Method,
     uri: Uri,

apps/api/src/middlewares/request_info.rs

@@ -0,0 +1,34 @@
+use axum::{extract::FromRequestParts, http::StatusCode};
+use uuid::Uuid;
+
+#[derive(Clone, Debug)]
+pub struct RequestInfo {
+    pub user_id: Option<Uuid>,
+}
+
+pub struct AuthenticatedRequestInfo {
+    pub user_id: Uuid,
+}
+
+impl<S> FromRequestParts<S> for AuthenticatedRequestInfo
+where
+    S: Send + Sync,
+{
+    type Rejection = StatusCode;
+
+    async fn from_request_parts(
+        parts: &mut axum::http::request::Parts,
+        _state: &S,
+    ) -> Result<Self, Self::Rejection> {
+        let request_info = parts
+            .extensions
+            .get::<RequestInfo>()
+            .ok_or(StatusCode::UNAUTHORIZED)?;
+
+        if let Some(user_id) = request_info.user_id {
+            Ok(AuthenticatedRequestInfo { user_id })
+        } else {
+            Err(StatusCode::UNAUTHORIZED)
+        }
+    }
+}

apps/api/src/middlewares/require_auth.rs

@@ -0,0 +1,109 @@
+use std::sync::Arc;
+
+use axum::{
+    extract::State,
+    http::{Request, StatusCode},
+    middleware::Next,
+    response::Response,
+};
+use axum_extra::extract::cookie::CookieJar;
+use tracing::debug;
+use uuid::Uuid;
+
+use crate::{
+    errors::service_error::ServiceError, helpers::constants::JWT_COOKIE_NAME,
+    middlewares::request_info::RequestInfo, routes::AppState,
+};
+
+pub async fn require_auth(
+    cookies: CookieJar,
+    State(state): State<Arc<AppState>>,
+    req: Request<axum::body::Body>,
+    next: Next,
+) -> Result<Response, StatusCode> {
+    // get jwt from cookies
+    let auth_service = &state.service.auth_state.authentication;
+    let token = if let Some(cookie) = cookies.get(JWT_COOKIE_NAME) {
+        cookie.value().to_string()
+    } else {
+        debug!("No JWT cookie found. cookies: {:?}", cookies);
+        return handle_unauthenticated().await;
+    };
+
+    // validate jwt
+    let is_valid = auth_service.is_valid_jwt(&token, None).await;
+    let user_id = match is_valid {
+        Ok(Some(claims)) => claims
+            .sub
+            .parse::<Uuid>()
+            .map_err(|_| StatusCode::UNAUTHORIZED)?,
+        Ok(None) => return handle_unauthenticated().await,
+        Err(err) => {
+            tracing::error!("Error validating JWT: {}", err);
+            return Err(StatusCode::INTERNAL_SERVER_ERROR);
+        }
+    };
+
+    // ensure user exists
+    if let Err(err) = state.service.user.get_user_by_id(user_id, None).await {
+        match err {
+            ServiceError::NotFound(_) => return handle_unauthenticated().await,
+            _ => {
+                tracing::error!("Error fetching user by ID: {}", err);
+                return Err(StatusCode::INTERNAL_SERVER_ERROR);
+            }
+        }
+    }
+
+    let mut req = req;
+    let user = req
+        .extensions_mut()
+        .get_or_insert_with(|| RequestInfo { user_id: None });
+    user.user_id = Some(user_id);
+
+    Ok(next.run(req).await)
+}
+
+async fn handle_unauthenticated() -> Result<Response, StatusCode> {
+    // TODO: log unauthenticated access attempts
+    Err(StatusCode::UNAUTHORIZED)
+}
+
+#[cfg(test)]
+pub mod mock {
+
+    use super::*;
+
+    pub const REQUEST_AUTH_USER_ID_HEADER: &str = "x-mock-authenticated-user-id";
+    pub const REQUEST_AUTH_USER_INVALID_HEADER: &str = "x-mock-authenticated-invalid";
+
+    pub async fn mock_require_auth(
+        req: Request<axum::body::Body>,
+        next: Next,
+    ) -> Result<Response, StatusCode> {
+        let mut req = req;
+        let invalid_present = req
+            .headers()
+            .get(REQUEST_AUTH_USER_INVALID_HEADER)
+            .is_some();
+        let user_id_header = req.headers().get(REQUEST_AUTH_USER_ID_HEADER).cloned();
+
+        if invalid_present {
+            return handle_unauthenticated().await;
+        }
+
+        let user = req
+            .extensions_mut()
+            .get_or_insert_with(|| RequestInfo { user_id: None });
+        user.user_id = Some(if let Some(user_id_header) = user_id_header {
+            let user_id_str = user_id_header
+                .to_str()
+                .map_err(|_| StatusCode::UNAUTHORIZED)?;
+            Uuid::parse_str(user_id_str).map_err(|_| StatusCode::UNAUTHORIZED)?
+        } else {
+            Uuid::new_v4()
+        });
+
+        Ok(next.run(req).await)
+    }
+}

apps/api/src/routes.rs

@@ -8,35 +8,45 @@ use std::sync::Arc;
 use axum::{Extension, Router};
 use migration::sea_orm::DatabaseConnection;
 
-use crate::{middlewares, services::settings::SettingsStore};
+use crate::{
+    configs::{ProgramSettings, server::CORSSettings},
+    middlewares,
+    services::{
+        AppService, ServiceState,
+        auth::authentication::{AuthenticationService, strategies::password::PasswordStrategy},
+    },
+};
 
 #[derive(Clone)]
 pub struct AppState {
-    // TODO: remove dead_code allowances when fields are used
-    #[allow(dead_code)]
     pub database_connection: Arc<DatabaseConnection>,
-    // TODO: remove dead_code allowances when fields are used
-    #[allow(dead_code)]
     pub service: Arc<AppService>,
+    pub config: Arc<ProgramSettings>,
 }
 
-pub type ServiceState<T> = Arc<T>;
-
-pub struct AppService {
-    #[allow(dead_code)] // TODO: remove when used
-    pub settings: ServiceState<dyn SettingsStore>,
+pub struct AuthStrategy {
+    pub password: ServiceState<PasswordStrategy>,
 }
 
-pub fn get_root_router(state: impl Into<Arc<AppState>>) -> Router {
+pub struct AuthState {
+    pub strategy: AuthStrategy,
+    pub authentication: ServiceState<dyn AuthenticationService>,
+}
+
+pub fn get_root_router(
+    state: impl Into<Arc<AppState>>,
+    cors_settings: Arc<CORSSettings>,
+) -> Router {
     let mut router = Router::new();
+    let state = state.into();
 
     router = router
-        .nest("/api", api::get_api_router())
+        .nest("/api", api::get_api_router(state.clone()))
         .merge(view::get_view_router());
 
-    router = middlewares::apply_root_middleware(router);
+    router = middlewares::apply_root_middleware(router, state.clone(), cors_settings);
 
-    router = router.layer(Extension(state.into()));
+    router = router.layer(Extension(state.clone()));
 
     router
 }

apps/api/src/routes/api.rs

@@ -1,13 +1,22 @@
+mod auth;
 mod health;
+mod helper;
 mod openapi;
+mod restricted;
+
+use std::sync::Arc;
+
+use crate::routes::AppState;
 
 pub use self::openapi::ApiDoc;
 
 use axum::{Router, response::IntoResponse, routing::any};
 
-pub fn get_api_router() -> Router {
+pub fn get_api_router(state: Arc<AppState>) -> Router {
     Router::new()
-        .nest("/health", health::get_health_router())
+        .nest("/health", health::get_health_router(state.clone()))
+        .merge(auth::get_basic_auth_router(state.clone()))
+        .merge(restricted::get_restricted_router(state.clone()))
         // explicit fallback for unmatched API routes
         .route("/{*wildcard}", any(api_fallback_handler))
 }

apps/api/src/routes/api/auth.rs

@@ -0,0 +1,15 @@
+pub mod init_admin;
+pub mod login;
+
+use std::sync::Arc;
+
+use axum::{Router, routing::post};
+
+use crate::routes::AppState;
+
+pub fn get_basic_auth_router(state: Arc<AppState>) -> Router {
+    Router::new()
+        .route("/auth/login", post(login::login))
+        .route("/auth/init_admin", post(init_admin::init_admin))
+        .with_state(state)
+}

apps/api/src/routes/api/auth/init_admin.rs

@@ -0,0 +1,143 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::State,
+    http::StatusCode,
+    response::{IntoResponse, Response},
+};
+use database::generated::entities::user;
+use sea_orm::{ColumnTrait, EntityTrait, QueryFilter, TransactionTrait};
+use serde::{Deserialize, Serialize};
+use serde_json::{Value, from_value};
+use tracing::{debug, error, info, warn};
+
+use crate::{
+    helpers::constants::ADMIN_INIT_SECRET_KEY,
+    routes::{AppState, api::openapi::tag::AUTH_TAG},
+    services::auth::user::NewUser,
+};
+
+/// Login request payload
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct AdminInitRequest {
+    username: String,
+    password: String,
+    // The secret key required to initialize the admin user
+    setup_secret: String,
+}
+
+/// Initializes the admin user
+///
+/// Initializes the admin user if no admin user exists and the correct setup secret is provided.
+#[utoipa::path(
+        post,
+        path = "/api/auth/init_admin",
+        request_body = AdminInitRequest,
+        responses(
+            (status = 200, description = "Admin user initialized successfully"),
+            (status = 400, description = "Invalid request payload"),
+            (status = 401, description = "Unauthorized: Admin user already exists or invalid setup secret"),
+            (status = 500, description = "Internal server error"),
+        ),
+        tag = AUTH_TAG,
+    )]
+pub async fn init_admin(
+    State(state): State<Arc<AppState>>,
+    Json(payload): Json<Value>,
+) -> Response {
+    if user::Entity::find()
+        .filter(user::Column::IsAdmin.eq(true))
+        .filter(user::Column::IsActive.eq(true))
+        .one(state.database_connection.as_ref())
+        .await
+        .map_err(|err| {
+            error!("Failed to query for existing admin user: {}", err);
+            StatusCode::INTERNAL_SERVER_ERROR
+        })
+        .unwrap_or(None)
+        .is_some()
+    {
+        warn!("Admin user already exists. Skipping admin initialization.");
+        return (StatusCode::UNAUTHORIZED).into_response();
+    }
+
+    let init_request: AdminInitRequest = match from_value(payload) {
+        Ok(req) => req,
+        Err(e) => {
+            warn!("Invalid login request: {}", e);
+            return (StatusCode::BAD_REQUEST).into_response();
+        }
+    };
+
+    let admin_secret = match state
+        .service
+        .settings
+        .get_setting(ADMIN_INIT_SECRET_KEY)
+        .await
+    {
+        Ok(secret) => secret,
+        Err(e) => {
+            error!(
+                "Failed to retrieve admin initialization secret. Invalid internal state?: {}",
+                e
+            );
+            return (StatusCode::INTERNAL_SERVER_ERROR).into_response();
+        }
+    };
+
+    if init_request.setup_secret != admin_secret {
+        info!("{},{}", init_request.setup_secret, admin_secret);
+        warn!("Invalid admin initialization secret provided.");
+        return (StatusCode::UNAUTHORIZED).into_response();
+    }
+
+    let mut tx = match state.database_connection.begin().await {
+        Ok(tx) => tx,
+        Err(e) => {
+            error!("Failed to start transaction: {}", e);
+            return (StatusCode::INTERNAL_SERVER_ERROR).into_response();
+        }
+    };
+
+    let user = match state
+        .service
+        .user
+        .create_user(
+            NewUser {
+                username: init_request.username,
+                is_admin: true,
+            },
+            Some(&mut tx),
+        )
+        .await
+    {
+        Ok(user) => user,
+        Err(e) => {
+            error!("Failed to initialize admin user: {}", e);
+            return (StatusCode::INTERNAL_SERVER_ERROR).into_response();
+        }
+    };
+
+    debug!("Created admin user with ID: {}", user.id);
+    match state
+        .service
+        .auth_state
+        .strategy
+        .password
+        .create_identity(user.id, &init_request.password, Some(&mut tx))
+        .await
+    {
+        Ok(_) => {}
+        Err(e) => {
+            error!("Failed to create admin user identity: {}", e);
+            return (StatusCode::INTERNAL_SERVER_ERROR).into_response();
+        }
+    };
+
+    tx.commit().await.unwrap_or_else(|e| {
+        error!("Failed to commit transaction: {}", e);
+    });
+
+    (StatusCode::OK).into_response()
+}

apps/api/src/routes/api/auth/login.rs

@@ -0,0 +1,107 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    body::Body,
+    extract::State,
+    http::{StatusCode, header::SET_COOKIE},
+    response::{IntoResponse, Response},
+};
+use serde::{Deserialize, Serialize};
+use serde_json::{Value, from_value};
+use tracing::{error, warn};
+
+use crate::{
+    helpers::constants::JWT_COOKIE_NAME,
+    routes::{AppState, api::openapi::tag::AUTH_TAG},
+};
+
+/// Login request payload
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct LoginRequest {
+    username: String,
+    password: String,
+}
+
+/// Login endpoint
+///
+/// Authenticates a user and returns a JWT in an HttpOnly cookie.
+#[utoipa::path(
+        post,
+        path = "/api/auth/login",
+        request_body = LoginRequest,
+        responses(
+            (status = 200, description = "User authenticated successfully", body = ()),
+            (status = 401, description = "Authentication failed"),
+            (status = 500, description = "Internal server error"),
+        ),
+        tag = AUTH_TAG,
+    )]
+pub async fn login(State(state): State<Arc<AppState>>, Json(payload): Json<Value>) -> Response {
+    let login_request: LoginRequest = match from_value(payload) {
+        Ok(req) => req,
+        Err(e) => {
+            warn!("Invalid login request: {}", e);
+            return (StatusCode::BAD_REQUEST).into_response();
+        }
+    };
+
+    let user_id = match state
+        .service
+        .auth_state
+        .strategy
+        .password
+        .authenticate(&login_request.username, &login_request.password, None)
+        .await
+    {
+        Ok(user_id) => user_id,
+        Err(e) => {
+            warn!(
+                "Authentication failed for user {}: {}",
+                login_request.username, e
+            );
+            return (StatusCode::UNAUTHORIZED).into_response();
+        }
+    };
+
+    let (jwt, claims) = match state
+        .service
+        .auth_state
+        .authentication
+        .generate_jwt(user_id, 3600)
+        .await
+    {
+        Ok(token) => token,
+        Err(e) => {
+            error!("Error generating JWT for user {}: {}", user_id, e);
+            return (StatusCode::INTERNAL_SERVER_ERROR).into_response();
+        }
+    };
+
+    let response_builder = Response::builder()
+        .status(StatusCode::OK)
+        // add jwt as cookie
+        .header(
+            SET_COOKIE,
+            format!(
+                "{}={}; HttpOnly; Path=/; Max-Age={}; SameSite=Strict;{}",
+                JWT_COOKIE_NAME,
+                jwt,
+                claims.exp - claims.iat,
+                if state.config.server.cookies.secure {
+                    " Secure;"
+                } else {
+                    ""
+                }
+            ),
+        )
+        .body(Body::from(()));
+
+    match response_builder {
+        Ok(resp) => resp,
+        Err(e) => {
+            error!("Error building response: {}", e);
+            (StatusCode::INTERNAL_SERVER_ERROR).into_response()
+        }
+    }
+}

apps/api/src/routes/api/health.rs

@@ -5,8 +5,13 @@ use std::sync::Arc;
 
 use axum::{Router, routing::get};
 
-pub fn get_health_router() -> Router {
+use crate::routes::{AppState, api::health::state::AppStateWithHealth};
+
+pub fn get_health_router(app_state: Arc<AppState>) -> Router {
     Router::new()
         .route("/info", get(info::get_health_info))
-        .with_state(Arc::new(state::HealthState::default()))
+        .with_state(Arc::new(AppStateWithHealth {
+            app_state: app_state.clone(),
+            health_state: Arc::new(state::HealthState::default()),
+        }))
 }

apps/api/src/routes/api/health/info.rs

@@ -3,8 +3,9 @@ use std::sync::Arc;
 use axum::{Json, extract::State, http::StatusCode};
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
+use tracing::error;
 
-use crate::routes::api::{health::state::HealthState, openapi::tag::HEALTH_TAG};
+use crate::routes::api::{health::state::AppStateWithHealth, openapi::tag::HEALTH_TAG};
 
 const STATUS_HEALTHY: &str = "healthy";
 const STATUS_UNHEALTHY: &str = "unhealthy";
@@ -20,6 +21,8 @@ pub struct HealthInfo {
     pub up_since: DateTime<Utc>,
     /// List of error messages if unhealthy
     pub errors: Option<Vec<String>>,
+    /// Is initialized
+    pub is_initialized: bool,
 }
 
 /// Health check endpoint
@@ -35,12 +38,23 @@ pub struct HealthInfo {
         tag = HEALTH_TAG,
     )]
 pub async fn get_health_info(
-    State(state): State<Arc<HealthState>>,
+    State(app_state_with_health): State<Arc<AppStateWithHealth>>,
 ) -> (StatusCode, Json<HealthInfo>) {
     #[allow(unused_mut)]
     let mut errors = vec![];
 
     let is_healthy = errors.is_empty();
+    let health_state = &app_state_with_health.health_state;
+    let app_state = &app_state_with_health.app_state;
+
+    let is_initialized = match app_state.service.server_state.is_server_initialized().await {
+        Ok(initialized) => initialized,
+        Err(err) => {
+            errors.push("Failed to determine if server is initialized".to_string());
+            error!("Error checking server initialization status: {}", err);
+            false
+        }
+    };
 
     (
         if is_healthy {
@@ -55,8 +69,9 @@ pub async fn get_health_info(
                 STATUS_UNHEALTHY.into()
             },
             version: env!("CARGO_PKG_VERSION").into(),
-            up_since: *state.get_start_at(),
+            up_since: *health_state.get_start_at(),
             errors: if is_healthy { None } else { Some(errors) },
+            is_initialized,
         }),
     )
 }
@@ -64,29 +79,60 @@ pub async fn get_health_info(
 #[cfg(test)]
 mod test {
     use super::*;
+
+    use crate::configs::FromConfig;
+    use crate::routes::{AppState, api::health::state::HealthState};
+    use crate::services::get_app_service;
+
     use axum::body::to_bytes;
     use axum::{
         Router,
         body::Body,
         http::{Request, StatusCode},
     };
+    use sea_orm::MockDatabase;
     use tower::ServiceExt;
 
     #[tokio::test]
     async fn test_get_health_info() {
         let health_state = Arc::new(HealthState::default());
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+        let db = Arc::new(db);
+
+        let app_state = Arc::new(AppState {
+            database_connection: db.clone(),
+            config: Arc::new(crate::configs::ProgramSettings::mock()),
+            service: Arc::new(get_app_service(
+                &db.clone(),
+                &crate::configs::ProgramSettings::mock(),
+            )),
+        });
+
         let app = Router::new()
             .route("/info", axum::routing::get(get_health_info))
-            .with_state(health_state);
+            .with_state(Arc::new(AppStateWithHealth {
+                app_state: app_state.clone(),
+                health_state: health_state.clone(),
+            }));
 
         let response = app
-            .oneshot(Request::builder().uri("/info").body(Body::empty()).unwrap())
+            .oneshot(
+                Request::builder()
+                    .uri("/info")
+                    .body(Body::empty())
+                    .expect("Failed to build request"),
+            )
             .await
             .unwrap();
 
         assert_eq!(response.status(), StatusCode::OK);
-        let body = to_bytes(response.into_body(), 1024 * 1024).await.unwrap(); // Set limit to 1 MB
-        let health_info: HealthInfo = serde_json::from_slice(&body).unwrap();
+        let body = to_bytes(response.into_body(), 1024 * 1024)
+            .await
+            .expect("Failed to read response body"); // Set limit to 1 MB
+        let health_info: HealthInfo =
+            serde_json::from_slice(&body).expect("Failed to deserialize response body");
         assert_eq!(health_info.status, STATUS_HEALTHY);
         assert_eq!(health_info.version, env!("CARGO_PKG_VERSION"));
         assert!(health_info.errors.is_none());

apps/api/src/routes/api/health/state.rs

@@ -1,5 +1,14 @@
+use std::sync::Arc;
+
 use chrono::{DateTime, Utc};
 
+use crate::routes::AppState;
+
+pub struct AppStateWithHealth {
+    pub app_state: Arc<AppState>,
+    pub health_state: Arc<HealthState>,
+}
+
 pub struct HealthState {
     start_at: DateTime<Utc>,
 }

apps/api/src/routes/api/helper.rs

@@ -0,0 +1 @@
+pub mod pagination;

apps/api/src/routes/api/helper/pagination.rs

@@ -0,0 +1,76 @@
+use axum::{
+    extract::FromRequestParts,
+    http::{StatusCode, request::Parts},
+};
+use serde::{Deserialize, Serialize};
+
+use crate::helpers::database::PaginationFilter;
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema, Clone)]
+/// Pagination parameters for API requests
+pub struct Pagination {
+    /// Page number (1-based)
+    pub page: u32,
+    /// Items per page
+    pub per_page: u32,
+}
+
+impl Default for Pagination {
+    fn default() -> Self {
+        Self {
+            page: 1,
+            per_page: 20,
+        }
+    }
+}
+
+impl From<Pagination> for PaginationFilter {
+    fn from(pagination: Pagination) -> Self {
+        Self {
+            page: pagination.page as u64,
+            per_page: pagination.per_page as u64,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+/// Pagination information included in API responses
+pub struct PaginationInfo {
+    /// Total number of items
+    pub total_items: u64,
+    /// Total number of pages
+    pub total_pages: u32,
+    /// Current page number
+    pub current_page: u32,
+    /// Items per page
+    pub per_page: u32,
+}
+
+/// Extractor for pagination parameters from query string
+pub struct ExtractPagination(pub Pagination);
+
+impl<S> FromRequestParts<S> for ExtractPagination
+where
+    S: Send + Sync,
+{
+    type Rejection = (StatusCode, &'static str);
+
+    async fn from_request_parts(parts: &mut Parts, _state: &S) -> Result<Self, Self::Rejection> {
+        let query = parts.uri.query().unwrap_or("");
+        let pagination: Pagination = serde_urlencoded::from_str(query).unwrap_or_default();
+
+        // validation
+        if pagination.page == 0 {
+            return Err((StatusCode::BAD_REQUEST, "page must be greater than 0"));
+        }
+
+        if pagination.per_page < 1 || pagination.per_page > 100 {
+            return Err((
+                StatusCode::BAD_REQUEST,
+                "per_page must be between 1 and 100",
+            ));
+        }
+
+        Ok(ExtractPagination(pagination))
+    }
+}

apps/api/src/routes/api/openapi.rs

@@ -1,18 +1,57 @@
 pub mod tag {
     /// Health tag constant
     pub const HEALTH_TAG: &str = "Health";
+    pub const AUTH_TAG: &str = "Authentication";
+    pub const USER_TAG: &str = "User";
+    pub const NGINX_TAG: &str = "Nginx";
 }
 
 #[derive(utoipa::OpenApi)]
 #[openapi(
   paths(
-    crate::routes::api::health::info::get_health_info
+    crate::routes::api::health::info::get_health_info,
+    // Authentication paths
+    crate::routes::api::auth::login::login,
+    crate::routes::api::auth::init_admin::init_admin,
+    // User management paths
+    crate::routes::api::restricted::user::me::get_user_info,
+    // Nginx upstream management
+    crate::routes::api::restricted::nginx::upstream::create_upstream::create_upstream,
+    crate::routes::api::restricted::nginx::upstream::create_upstream_target::add_upstream_target,
+    crate::routes::api::restricted::nginx::upstream::get_upstream::get_upstream_list,
+    crate::routes::api::restricted::nginx::upstream::get_upstream::get_upstream,
+    crate::routes::api::restricted::nginx::upstream::get_upstream_target::get_upstream_target,
+    crate::routes::api::restricted::nginx::upstream::update_upstream::update_upstream,
+    crate::routes::api::restricted::nginx::upstream::update_upstream_target::update_upstream_target,
+    crate::routes::api::restricted::nginx::upstream::remove_upstream::remove_upstream,
+    crate::routes::api::restricted::nginx::upstream::remove_upstream_target::remove_upstream_target,
   ),
   components(
-      schemas(crate::routes::api::health::info::HealthInfo) // Register any schemas used in your paths
+      schemas(crate::routes::api::health::info::HealthInfo),
+      // Authentication schemas
+      schemas(crate::routes::api::auth::login::LoginRequest),
+      schemas(crate::routes::api::auth::init_admin::AdminInitRequest),
+      // User management schemas
+      schemas(crate::routes::api::restricted::user::me::UserInfo),
+      // Nginx upstream schemas
+      schemas(crate::routes::api::restricted::nginx::upstream::create_upstream::CreateUpstreamRequestBody),
+      schemas(crate::routes::api::restricted::nginx::upstream::create_upstream_target::CreateUpstreamTargetInfo),
+      schemas(crate::routes::api::restricted::nginx::upstream::get_upstream::GetUpstreamParams),
+      schemas(crate::routes::api::restricted::nginx::upstream::get_upstream_target::GetUpstreamTargetsParams),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpstreamTargetInfo),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpstreamInfoResponse),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpstreamListResponse),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpstreamTargetInfoResponse),
+      schemas(crate::routes::api::restricted::nginx::upstream::update_upstream::UpdateUpstreamRequestBody),
+      schemas(crate::routes::api::restricted::nginx::upstream::update_upstream_target::UpdateUpstreamTargetRequestBody),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpdateUpstreamInfoResponse),
+      schemas(crate::routes::api::restricted::nginx::upstream::info::response::UpdateUpstreamTargetInfoResponse),
   ),
   tags(
-      (name = tag::HEALTH_TAG, description = "Health information API")
+      (name = tag::HEALTH_TAG, description = "Health information API"),
+      (name = tag::AUTH_TAG, description = "Authentication API"),
+      (name = tag::USER_TAG, description = "User management API"),
+      (name = tag::NGINX_TAG, description = "Nginx management API")
   )
 )]
 pub struct ApiDoc;

apps/api/src/routes/api/restricted.rs

@@ -0,0 +1,18 @@
+pub mod nginx;
+pub mod user;
+
+use std::sync::Arc;
+
+use axum::Router;
+
+use crate::{middlewares::require_auth::require_auth, routes::AppState};
+
+pub fn get_restricted_router(state: Arc<AppState>) -> Router {
+    Router::new()
+        .nest("/user", user::get_user_router(state.clone()))
+        .nest("/nginx", nginx::get_nginx_router(state.clone()))
+        .layer(axum::middleware::from_fn_with_state(
+            state.clone(),
+            require_auth,
+        ))
+}

apps/api/src/routes/api/restricted/nginx.rs

@@ -0,0 +1,11 @@
+pub mod upstream;
+
+use std::sync::Arc;
+
+use axum::Router;
+
+use crate::routes::AppState;
+
+pub fn get_nginx_router(state: Arc<AppState>) -> Router {
+    Router::new().merge(upstream::get_upstream_router(state.clone()))
+}

apps/api/src/routes/api/restricted/nginx/upstream.rs

@@ -0,0 +1,43 @@
+pub mod create_upstream;
+pub mod create_upstream_target;
+pub mod get_upstream;
+pub mod get_upstream_target;
+pub mod info;
+pub mod remove_upstream;
+pub mod remove_upstream_target;
+pub mod update_upstream;
+pub mod update_upstream_target;
+
+use std::sync::Arc;
+
+use axum::{
+    Router,
+    routing::{get, post},
+};
+
+use crate::routes::AppState;
+
+pub fn get_upstream_router(state: Arc<AppState>) -> Router {
+    Router::new()
+        .route(
+            "/upstreams",
+            get(get_upstream::get_upstream_list).post(create_upstream::create_upstream),
+        )
+        .route(
+            "/upstreams/{upstream_id}",
+            get(get_upstream::get_upstream)
+                .patch(update_upstream::update_upstream)
+                .delete(remove_upstream::remove_upstream),
+        )
+        .route(
+            "/upstreams/{upstream_id}/targets",
+            post(create_upstream_target::add_upstream_target),
+        )
+        .route(
+            "/upstream_targets/{upstream_target_id}",
+            get(get_upstream_target::get_upstream_target)
+                .patch(update_upstream_target::update_upstream_target)
+                .delete(remove_upstream_target::remove_upstream_target),
+        )
+        .with_state(state)
+}

apps/api/src/routes/api/restricted/nginx/upstream/create_upstream.rs

@@ -0,0 +1,367 @@
+use std::sync::Arc;
+
+use axum::{Json, extract::State, response::Result as AxumResult};
+use sea_orm::TransactionTrait;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{
+        AppState,
+        api::{
+            openapi::tag::NGINX_TAG,
+            restricted::nginx::upstream::info::response::UpstreamInfoResponse,
+        },
+    },
+    services::nginx::info::upstream::UpstreamCreateInfo,
+};
+
+#[derive(serde::Deserialize, utoipa::ToSchema, serde::Serialize)]
+pub struct UpstreamTargetInfo {
+    pub host: String,
+    pub port: i64,
+    pub weight: Option<i64>,
+    pub is_backup: Option<bool>,
+    pub enabled: Option<bool>,
+}
+
+pub struct ConcreteUpstreamTargetInfo {
+    pub host: String,
+    pub port: i64,
+    pub weight: i64,
+    pub is_backup: bool,
+    pub enabled: bool,
+}
+
+impl From<UpstreamTargetInfo> for ConcreteUpstreamTargetInfo {
+    fn from(info: UpstreamTargetInfo) -> Self {
+        Self {
+            host: info.host,
+            port: info.port,
+            weight: info.weight.unwrap_or(1),
+            is_backup: info.is_backup.unwrap_or(false),
+            enabled: info.enabled.unwrap_or(true),
+        }
+    }
+}
+
+#[derive(serde::Deserialize, utoipa::ToSchema, serde::Serialize)]
+pub struct CreateUpstreamRequestBody {
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: Option<String>,
+    pub sticky_session: Option<bool>,
+    pub upstream_targets: Vec<UpstreamTargetInfo>,
+}
+
+struct ConcreteCreateUpstreamRequestBody {
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: String,
+    pub sticky_session: bool,
+    pub upstream_targets: Vec<ConcreteUpstreamTargetInfo>,
+}
+
+impl From<CreateUpstreamRequestBody> for ConcreteCreateUpstreamRequestBody {
+    fn from(payload: CreateUpstreamRequestBody) -> Self {
+        Self {
+            name: payload.name,
+            protocol: payload.protocol,
+            algorithm: payload
+                .algorithm
+                .unwrap_or_else(|| "round_robin".to_string()),
+            sticky_session: payload.sticky_session.unwrap_or(false),
+            upstream_targets: payload
+                .upstream_targets
+                .into_iter()
+                .map(|target| target.into())
+                .collect(),
+        }
+    }
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    post,
+    path = "/api/nginx/upstreams",
+    request_body = CreateUpstreamRequestBody,
+    responses(
+        (status = 200, description = "Upstream created successfully", body = UpstreamInfoResponse),
+        (status = 401, description = "Unauthorized"),
+        (status = 422, description = "Invalid request"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn create_upstream(
+    request_info: AuthenticatedRequestInfo,
+    State(state): State<Arc<AppState>>,
+    Json(payload): Json<CreateUpstreamRequestBody>,
+) -> AxumResult<Json<UpstreamInfoResponse>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+    let concrete_payload: ConcreteCreateUpstreamRequestBody = payload.into();
+
+    let create_info = UpstreamCreateInfo {
+        name: concrete_payload.name,
+        protocol: concrete_payload.protocol,
+        algorithm: concrete_payload.algorithm,
+        sticky_session: concrete_payload.sticky_session,
+        created_by: Some(request_info.user_id),
+        upstream_targets: concrete_payload
+            .upstream_targets
+            .into_iter()
+            .map(
+                |target| crate::services::nginx::info::upstream_target::UpstreamTargetCreateInfo {
+                    target_host: target.host,
+                    target_port: target.port,
+                    weight: target.weight,
+                    is_backup: target.is_backup,
+                    enabled: target.enabled,
+                    upstream_id: uuid::Uuid::nil(), // Placeholder, will be set in service
+                },
+            )
+            .collect(),
+    };
+
+    let mut tx = state.database_connection.begin().await?;
+    let upstream_info = upstream_service
+        .create_upstream(create_info, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(upstream_info.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        routes::api::restricted::nginx::upstream::{
+            create_upstream::{CreateUpstreamRequestBody, UpstreamTargetInfo as ReqTarget},
+            get_upstream_router,
+        },
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ))
+    }
+
+    #[tokio::test]
+    async fn handler_create_upstream_succeeds_returns_created() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "new_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_id = uuid::Uuid::new_v4();
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        // service will likely perform an insert and then query to return created models
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![up_model.clone()]])
+            .append_query_results(vec![vec![target_model.clone()]])
+            // additional query result for regenerate_and_apply_config -> generate_config
+            // `find_with_related` returns rows of `(upstream, Option<target>)` which
+            // the mock DB expects as `(Model, Option<Model>)` per row.
+            .append_query_results(vec![vec![(up_model.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamRequestBody {
+            name: "new_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: vec![ReqTarget {
+                host: "127.0.0.1".to_string(),
+                port: 8080,
+                weight: None,
+                is_backup: None,
+                enabled: None,
+            }],
+        };
+
+        let res = server.post("/upstreams").json(&payload).await;
+
+        res.assert_status_ok();
+        let text = res.text();
+        let body: crate::routes::api::restricted::nginx::upstream::info::response::UpstreamInfoResponse =
+            serde_json::from_str(&text).expect("failed to parse json");
+
+        assert_eq!(body.id, up_id);
+        assert_eq!(body.name, "new_upstream");
+        assert_eq!(body.protocol, "http");
+        assert_eq!(body.upstream_targets.len(), 1);
+        assert_eq!(body.upstream_targets[0].id, target_id);
+    }
+
+    #[tokio::test]
+    async fn handler_create_upstream_invalid_payload_returns_bad_request() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        // missing required fields -> send empty object
+        let res = server.post("/upstreams").json(&serde_json::json!({})).await;
+        res.assert_status(StatusCode::UNPROCESSABLE_ENTITY);
+    }
+
+    #[tokio::test]
+    async fn handler_create_upstream_agent_error_returns_internal() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "new_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_id = uuid::Uuid::new_v4();
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        // configure mock agent to error on apply
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![up_model.clone()]])
+            .append_query_results(vec![vec![target_model.clone()]])
+            .append_query_results(vec![vec![(up_model.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ));
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamRequestBody {
+            name: "new_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: vec![ReqTarget {
+                host: "127.0.0.1".to_string(),
+                port: 8080,
+                weight: None,
+                is_backup: None,
+                enabled: None,
+            }],
+        };
+
+        let res = server.post("/upstreams").json(&payload).await;
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+
+    #[tokio::test]
+    async fn handler_create_upstream_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamRequestBody {
+            name: "new_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: vec![ReqTarget {
+                host: "127.0.0.1".to_string(),
+                port: 8080,
+                weight: None,
+                is_backup: None,
+                enabled: None,
+            }],
+        };
+
+        let res = server
+            .post("/upstreams")
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/create_upstream_target.rs

@@ -0,0 +1,310 @@
+use std::sync::Arc;
+
+use axum::{Json, extract::State, response::Result as AxumResult};
+use sea_orm::TransactionTrait;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{
+        AppState,
+        api::{
+            openapi::tag::NGINX_TAG,
+            restricted::nginx::upstream::info::response::UpstreamTargetInfoResponse,
+        },
+    },
+    services::nginx::info::upstream_target::UpstreamTargetCreateInfo,
+};
+
+#[derive(serde::Deserialize, utoipa::ToSchema, serde::Serialize)]
+pub struct CreateUpstreamTargetInfo {
+    pub upstream_id: uuid::Uuid,
+    pub host: String,
+    pub port: i64,
+    pub weight: Option<i64>,
+    pub is_backup: Option<bool>,
+    pub enabled: Option<bool>,
+}
+
+pub struct ConcreteCreateUpstreamTargetInfo {
+    pub upstream_id: uuid::Uuid,
+    pub host: String,
+    pub port: i64,
+    pub weight: i64,
+    pub is_backup: bool,
+    pub enabled: bool,
+}
+
+impl From<CreateUpstreamTargetInfo> for ConcreteCreateUpstreamTargetInfo {
+    fn from(info: CreateUpstreamTargetInfo) -> Self {
+        Self {
+            upstream_id: info.upstream_id,
+            host: info.host,
+            port: info.port,
+            weight: info.weight.unwrap_or(1),
+            is_backup: info.is_backup.unwrap_or(false),
+            enabled: info.enabled.unwrap_or(true),
+        }
+    }
+}
+
+#[axum::debug_handler]
+#[utoipa::path(
+    post,
+    path = "/api/nginx/upstreams/{upstream_id}/targets",
+    request_body = CreateUpstreamTargetInfo,
+    responses(
+        (status = 200, description = "Upstream target created successfully", body = UpstreamTargetInfoResponse),
+        (status = 401, description = "Unauthorized"),
+        (status = 422, description = "Invalid request"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn add_upstream_target(
+    _request_info: AuthenticatedRequestInfo,
+    State(state): State<Arc<AppState>>,
+    Json(payload): Json<CreateUpstreamTargetInfo>,
+) -> AxumResult<Json<UpstreamTargetInfoResponse>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+    let concrete_payload: ConcreteCreateUpstreamTargetInfo = payload.into();
+
+    let create_info = UpstreamTargetCreateInfo {
+        weight: concrete_payload.weight,
+        is_backup: concrete_payload.is_backup,
+        enabled: concrete_payload.enabled,
+        target_host: concrete_payload.host,
+        target_port: concrete_payload.port,
+        upstream_id: concrete_payload.upstream_id,
+    };
+
+    let mut tx = state.database_connection.begin().await?;
+    let upstream_info = upstream_service
+        .create_upstream_target(create_info, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(upstream_info.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        routes::api::restricted::nginx::upstream::{
+            create_upstream_target::CreateUpstreamTargetInfo, get_upstream_router,
+        },
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ))
+    }
+
+    #[tokio::test]
+    async fn handler_add_upstream_target_agent_error_returns_internal() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let target_id = uuid::Uuid::new_v4();
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        // configure mock agent to return an error on apply
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![target_model.clone()]])
+            .append_query_results(vec![vec![(up_model.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ));
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamTargetInfo {
+            upstream_id: up_id,
+            host: "127.0.0.1".to_string(),
+            port: 8080,
+            weight: None,
+            is_backup: None,
+            enabled: None,
+        };
+
+        let res = server
+            .post(&format!("/upstreams/{}/targets", up_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+
+    #[tokio::test]
+    async fn handler_add_upstream_target_succeeds_returns_created() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let target_id = uuid::Uuid::new_v4();
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![target_model.clone()]])
+            // additional query result for regenerate_and_apply_config -> generate_config
+            .append_query_results(vec![vec![(up_model.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamTargetInfo {
+            upstream_id: up_id,
+            host: "127.0.0.1".to_string(),
+            port: 8080,
+            weight: None,
+            is_backup: None,
+            enabled: None,
+        };
+
+        let res = server
+            .post(&format!("/upstreams/{}/targets", up_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status_ok();
+        let text = res.text();
+        let body: crate::routes::api::restricted::nginx::upstream::info::response::UpstreamTargetInfoResponse =
+            serde_json::from_str(&text).expect("failed to parse json");
+
+        assert_eq!(body.id, target_id);
+        assert_eq!(body.host, "127.0.0.1");
+        assert_eq!(body.port, 8080);
+        assert_eq!(body.upstream_id, up_id);
+    }
+
+    #[tokio::test]
+    async fn handler_add_upstream_target_invalid_payload_returns_bad_request() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server
+            .post(&format!("/upstreams/{}/targets", uuid::Uuid::new_v4()))
+            .json(&serde_json::json!({}))
+            .await;
+
+        res.assert_status(StatusCode::UNPROCESSABLE_ENTITY);
+    }
+
+    #[tokio::test]
+    async fn handler_add_upstream_target_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = CreateUpstreamTargetInfo {
+            upstream_id: uuid::Uuid::new_v4(),
+            host: "127.0.0.1".to_string(),
+            port: 8080,
+            weight: None,
+            is_backup: None,
+            enabled: None,
+        };
+
+        let res = server
+            .post(&format!("/upstreams/{}/targets", payload.upstream_id))
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/get_upstream.rs

@@ -0,0 +1,343 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, Query, State},
+    response::Result as AxumResult,
+};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::{
+    errors::{api_error::ApiError, service_error::ServiceError},
+    routes::{
+        AppState,
+        api::{
+            helper::pagination::{ExtractPagination, PaginationInfo},
+            openapi::tag::NGINX_TAG,
+            restricted::nginx::upstream::info::response::{
+                UpstreamInfoResponse, UpstreamListResponse,
+            },
+        },
+    },
+    services::nginx::upstream::GetUpstreamOptions,
+};
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct GetUpstreamParams {
+    pub include_targets: Option<bool>,
+}
+
+pub struct ConcreteGetUpstreamParams {
+    pub include_targets: bool,
+}
+
+impl From<GetUpstreamParams> for ConcreteGetUpstreamParams {
+    fn from(params: GetUpstreamParams) -> Self {
+        Self {
+            include_targets: params.include_targets.unwrap_or(false),
+        }
+    }
+}
+
+#[utoipa::path(
+    get,
+    path = "/api/nginx/upstreams",
+    responses(
+        (status = 200, description = "List upstreams", body = UpstreamListResponse),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn get_upstream_list(
+    ExtractPagination(pagination): ExtractPagination,
+    State(state): State<Arc<AppState>>,
+) -> AxumResult<Json<UpstreamListResponse>, ServiceError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+
+    let (upstreams_res, upstream_count_res) = tokio::join!(
+        upstream_service.get_upstreams(
+            Some(pagination.clone().into()),
+            Some(GetUpstreamOptions {
+                include_targets: true,
+                filter_by_enabled: false,
+            }),
+            None,
+        ),
+        upstream_service.get_total_upstreams(None, None),
+    );
+
+    let upstreams = upstreams_res?;
+    let upstream_count = upstream_count_res?;
+
+    //
+    Ok(Json(UpstreamListResponse {
+        items: upstreams.into_iter().map(|u| u.into()).collect(),
+        pagination: PaginationInfo {
+            total_items: upstream_count,
+            total_pages: if upstream_count == 0 {
+                0
+            } else {
+                (upstream_count as f32 / pagination.per_page as f32).ceil() as u32
+            },
+            current_page: pagination.page,
+            per_page: pagination.per_page,
+        },
+    }))
+}
+
+#[utoipa::path(
+    get,
+    path = "/api/nginx/upstreams/{upstream_id}",
+    responses(
+        (status = 200, description = "Get upstream info", body = UpstreamInfoResponse),
+        (status = 404, description = "Not found"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn get_upstream(
+    Path(upstream_id): Path<Uuid>,
+    Query(params): Query<GetUpstreamParams>,
+    State(_state): State<Arc<AppState>>,
+) -> AxumResult<Json<UpstreamInfoResponse>, ApiError> {
+    let concrete_params: ConcreteGetUpstreamParams = params.into();
+    let upstream_service = &_state.service.nginx.get_upstream_service();
+    let upstream_info = if concrete_params.include_targets {
+        upstream_service
+            .get_upstream(
+                upstream_id,
+                Some(GetUpstreamOptions {
+                    include_targets: true,
+                    filter_by_enabled: false,
+                }),
+                None,
+            )
+            .await?
+    } else {
+        upstream_service
+            .get_upstream(upstream_id, None, None)
+            .await?
+    };
+
+    //
+    Ok(Json(upstream_info.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::{collections::BTreeMap, sync::Arc};
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase, Value};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        routes::api::restricted::nginx::upstream::{
+            get_upstream_router, info::response::UpstreamInfoResponse,
+        },
+        services::get_app_service,
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let app_service = get_app_service(&Arc::new(db.clone()), &program_settings);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state)
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_list_returns_list() {
+        let u1 = upstream::Model {
+            id: uuid::Uuid::new_v4(),
+            name: "u1".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+        let u2 = upstream::Model {
+            id: uuid::Uuid::new_v4(),
+            name: "u2".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![
+                (u1.clone(), None::<upstream_target::Model>),
+                (u2.clone(), None::<upstream_target::Model>),
+            ]])
+            .append_query_results(vec![vec![BTreeMap::from([(
+                "count".to_string(),
+                Value::BigInt(Some(2)),
+            )])]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.get("/upstreams").await;
+        res.assert_status_ok();
+        let body = res.json::<UpstreamListResponse>();
+        assert_eq!(body.items.len(), 2);
+        assert_eq!(body.pagination.current_page, 1u32);
+        assert_eq!(body.pagination.total_pages, 1u32);
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_with_targets_returns_targets() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "with_targets".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "least_conn".to_string(),
+            sticky_session: true,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_model = upstream_target::Model {
+            id: uuid::Uuid::new_v4(),
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            // find_by_id -> returns upstream model
+            .append_query_results(vec![vec![up_model.clone()]])
+            // find targets -> returns the target(s)
+            .append_query_results(vec![vec![target_model.clone()]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let url = format!("/upstreams/{}?include_targets=true", up_id);
+        let res = server.get(&url).await;
+        res.assert_status_ok();
+        let body = res.json::<UpstreamInfoResponse>();
+        assert_eq!(body.id, up_id);
+        assert_eq!(body.upstream_targets.len(), 1);
+        assert_eq!(body.upstream_targets[0].target_host, "127.0.0.1");
+    }
+
+    #[tokio::test]
+    async fn extractor_pagination_validation_rejects_bad_values() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .append_query_results(vec![vec![BTreeMap::from([(
+                "count".to_string(),
+                Value::BigInt(Some(0)),
+            )])]])
+            .into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        // page = 0 should be rejected
+        let res = server.get("/upstreams?page=0&per_page=10").await;
+        res.assert_status(StatusCode::BAD_REQUEST);
+
+        // per_page out of range should be rejected
+        let res = server.get("/upstreams?page=1&per_page=0").await;
+        res.assert_status(StatusCode::BAD_REQUEST);
+
+        // valid values accepted
+        let res = server.get("/upstreams?page=2&per_page=5").await;
+        res.assert_status_ok();
+        let body = res.json::<UpstreamListResponse>();
+        assert_eq!(body.pagination.current_page, 2u32);
+        assert_eq!(body.pagination.per_page, 5u32);
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_not_found_returns_service_error() {
+        let up_id = uuid::Uuid::new_v4();
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let url = format!("/upstreams/{}?include_targets=false", up_id);
+        let res = server.get(&url).await;
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_without_targets_returns_info() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "simple_up".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            // find_by_id -> returns upstream model
+            .append_query_results(vec![vec![up_model.clone()]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        // include_targets omitted -> should not include targets
+        let url = format!("/upstreams/{}", up_id);
+        let res = server.get(&url).await;
+        res.assert_status_ok();
+        let body = res.json::<UpstreamInfoResponse>();
+        assert_eq!(body.id, up_id);
+        assert!(body.upstream_targets.is_empty());
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_list_empty_returns_empty_items() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .append_query_results(vec![vec![BTreeMap::from([(
+                "count".to_string(),
+                Value::BigInt(Some(0)),
+            )])]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.get("/upstreams?page=3&per_page=10").await;
+        res.assert_status_ok();
+        let body = res.json::<UpstreamListResponse>();
+        assert_eq!(body.items.len(), 0);
+        assert_eq!(body.pagination.current_page, 3u32);
+        assert_eq!(body.pagination.per_page, 10u32);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/get_upstream_target.rs

@@ -0,0 +1,193 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, Query, State},
+    response::Result as AxumResult,
+};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::{
+    errors::api_error::ApiError,
+    routes::{
+        AppState,
+        api::{
+            openapi::tag::NGINX_TAG,
+            restricted::nginx::upstream::info::response::UpstreamTargetInfo,
+        },
+    },
+};
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct GetUpstreamTargetsParams {
+    pub include_upstream: Option<bool>,
+}
+
+pub struct ConcreteGetUpstreamTargetsParams {
+    pub include_upstream: bool,
+}
+
+impl From<GetUpstreamTargetsParams> for ConcreteGetUpstreamTargetsParams {
+    fn from(params: GetUpstreamTargetsParams) -> Self {
+        Self {
+            include_upstream: params.include_upstream.unwrap_or(false),
+        }
+    }
+}
+
+#[utoipa::path(
+    get,
+    path = "/api/nginx/upstream_targets/{upstream_target_id}",
+    responses(
+        (status = 200, description = "Get upstream target info", body = UpstreamTargetInfo),
+        (status = 404, description = "Not found"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn get_upstream_target(
+    Path(upstream_target_id): Path<Uuid>,
+    Query(params): Query<GetUpstreamTargetsParams>,
+    State(_state): State<Arc<AppState>>,
+) -> AxumResult<Json<UpstreamTargetInfo>, ApiError> {
+    let concrete_params: ConcreteGetUpstreamTargetsParams = params.into();
+    let upstream_service = &_state.service.nginx.get_upstream_service();
+    let upstream_target_info = upstream_service
+        .get_upstream_target(
+            upstream_target_id,
+            if concrete_params.include_upstream {
+                Some(crate::services::nginx::upstream::GetUpstreamTargetOptions {
+                    include_upstream: true,
+                })
+            } else {
+                None
+            },
+            None,
+        )
+        .await?;
+    Ok(Json(upstream_target_info.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::configs::{FromConfig, ProgramSettings};
+
+    use crate::routes::api::restricted::nginx::upstream::get_upstream_router;
+    use crate::services::get_app_service;
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let app_service = get_app_service(&Arc::new(db.clone()), &program_settings);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state)
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_target_with_upstream_returns_upstream() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "with_targets".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "least_conn".to_string(),
+            sticky_session: true,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_id = uuid::Uuid::new_v4();
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            // query returns joined (upstream_target, upstream)
+            .append_query_results(vec![vec![(target_model.clone(), Some(up_model.clone()))]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let url = format!("/upstream_targets/{}?include_upstream=true", target_id);
+        let res = server.get(&url).await;
+        res.assert_status_ok();
+        let text = res.text();
+        let body: UpstreamTargetInfo = serde_json::from_str(&text).expect("failed to parse json");
+        assert_eq!(body.upstream_id, up_id);
+        assert!(body.upstream.is_some());
+        let upstream = body.upstream.expect("upstream to be present");
+        assert_eq!(upstream.id, up_id);
+        assert_eq!(upstream.name, "with_targets");
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_target_without_upstream_returns_info() {
+        let target_id = uuid::Uuid::new_v4();
+
+        let target_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "10.0.0.1".to_string(),
+            target_port: 9090,
+            weight: 5,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![target_model.clone()]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let url = format!("/upstream_targets/{}", target_id);
+        let res = server.get(&url).await;
+        res.assert_status_ok();
+        let text = res.text();
+        let body: UpstreamTargetInfo = serde_json::from_str(&text).expect("failed to parse json");
+        assert_eq!(body.id, target_id);
+        assert!(body.upstream.is_none());
+    }
+
+    #[tokio::test]
+    async fn handler_get_upstream_target_not_found_returns_service_error() {
+        let target_id = uuid::Uuid::new_v4();
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let url = format!("/upstream_targets/{}?include_upstream=false", target_id);
+        let res = server.get(&url).await;
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/info.rs

@@ -0,0 +1 @@
+pub mod response;

apps/api/src/routes/api/restricted/nginx/upstream/info/response.rs

@@ -0,0 +1,232 @@
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::routes::api::helper::pagination::PaginationInfo;
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamTargetInfo {
+    pub id: uuid::Uuid,
+    pub target_host: String,
+    pub target_port: i64,
+    pub enabled: bool,
+    pub is_backup: bool,
+    pub weight: i32,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_id: Uuid,
+    pub upstream: Option<UpstreamBasicInfo>,
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamBasicInfo {
+    pub id: Uuid,
+    pub name: String,
+    pub protocol: String,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+impl From<crate::services::nginx::info::upstream_target::UpstreamTargetInfo>
+    for UpstreamTargetInfo
+{
+    fn from(info: crate::services::nginx::info::upstream_target::UpstreamTargetInfo) -> Self {
+        Self {
+            id: info.id,
+            target_host: info.target_host,
+            target_port: info.target_port,
+            enabled: info.enabled,
+            is_backup: info.is_backup,
+            weight: info.weight as i32,
+            //
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+            //
+            upstream_id: info.upstream_id,
+            upstream: info.upstream.map(|u| UpstreamBasicInfo {
+                id: u.id,
+                name: u.name,
+                protocol: u.protocol,
+                created_at: u.created_at,
+                updated_at: u.updated_at,
+            }),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamTargetBasicInfo {
+    pub id: uuid::Uuid,
+    pub target_host: String,
+    pub target_port: i64,
+    pub enabled: bool,
+    pub is_backup: bool,
+    pub weight: i32,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+impl From<crate::services::nginx::info::upstream_target::UpstreamTargetInfo>
+    for UpstreamTargetBasicInfo
+{
+    fn from(info: crate::services::nginx::info::upstream_target::UpstreamTargetInfo) -> Self {
+        Self {
+            id: info.id,
+            target_host: info.target_host,
+            target_port: info.target_port,
+            enabled: info.enabled,
+            is_backup: info.is_backup,
+            weight: info.weight as i32,
+            //
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamInfoResponse {
+    pub id: uuid::Uuid,
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: String,
+    pub sticky_session: bool,
+    pub created_by: Option<uuid::Uuid>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_targets: Vec<UpstreamTargetBasicInfo>,
+}
+
+impl From<crate::services::nginx::info::upstream::UpstreamInfo> for UpstreamInfoResponse {
+    fn from(info: crate::services::nginx::info::upstream::UpstreamInfo) -> Self {
+        Self {
+            id: info.id,
+            name: info.name,
+            protocol: info.protocol,
+            algorithm: info.algorithm,
+            sticky_session: info.sticky_session,
+            created_by: info.created_by,
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+            upstream_targets: info
+                .upstream_targets
+                .into_iter()
+                .map(|t| t.into())
+                .collect(),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamListResponse {
+    pub items: Vec<UpstreamInfoResponse>,
+    pub pagination: PaginationInfo,
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpstreamTargetInfoResponse {
+    pub id: uuid::Uuid,
+    pub host: String,
+    pub port: i64,
+    pub enabled: bool,
+    pub is_backup: bool,
+    pub weight: i32,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_id: Uuid,
+}
+
+impl From<crate::services::nginx::info::upstream_target::UpstreamTargetInfo>
+    for UpstreamTargetInfoResponse
+{
+    fn from(info: crate::services::nginx::info::upstream_target::UpstreamTargetInfo) -> Self {
+        Self {
+            id: info.id,
+            host: info.target_host,
+            port: info.target_port,
+            enabled: info.enabled,
+            is_backup: info.is_backup,
+            weight: info.weight as i32,
+            //
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+            //
+            upstream_id: info.upstream_id,
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpdateUpstreamInfoResponse {
+    pub id: uuid::Uuid,
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: String,
+    pub sticky_session: bool,
+    pub created_by: Option<uuid::Uuid>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_targets: Vec<UpstreamTargetBasicInfo>,
+}
+
+impl From<crate::services::nginx::info::upstream::UpstreamInfo> for UpdateUpstreamInfoResponse {
+    fn from(info: crate::services::nginx::info::upstream::UpstreamInfo) -> Self {
+        Self {
+            id: info.id,
+            name: info.name,
+            protocol: info.protocol,
+            algorithm: info.algorithm,
+            sticky_session: info.sticky_session,
+            created_by: info.created_by,
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+            upstream_targets: info
+                .upstream_targets
+                .into_iter()
+                .map(|t| t.into())
+                .collect(),
+        }
+    }
+}
+
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UpdateUpstreamTargetInfoResponse {
+    pub id: uuid::Uuid,
+    pub host: String,
+    pub port: i64,
+    pub enabled: bool,
+    pub is_backup: bool,
+    pub weight: i32,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_id: Uuid,
+}
+
+impl From<crate::services::nginx::info::upstream_target::UpstreamTargetInfo>
+    for UpdateUpstreamTargetInfoResponse
+{
+    fn from(info: crate::services::nginx::info::upstream_target::UpstreamTargetInfo) -> Self {
+        Self {
+            id: info.id,
+            host: info.target_host,
+            port: info.target_port,
+            enabled: info.enabled,
+            is_backup: info.is_backup,
+            weight: info.weight as i32,
+            //
+            created_at: info.created_at,
+            updated_at: info.updated_at,
+            upstream_id: info.upstream_id,
+        }
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/remove_upstream.rs

@@ -0,0 +1,238 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, State},
+    response::Result as AxumResult,
+};
+use sea_orm::TransactionTrait;
+use uuid::Uuid;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{AppState, api::openapi::tag::NGINX_TAG},
+};
+
+#[utoipa::path(
+    delete,
+    path = "/api/nginx/upstreams/{upstream_id}",
+    responses(
+        (status = 200, description = "Upstream removed successfully", body = ()),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Not found"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn remove_upstream(
+    _request_info: AuthenticatedRequestInfo,
+    Path(upstream_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> AxumResult<Json<()>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+
+    let mut tx = state.database_connection.begin().await?;
+    upstream_service
+        .delete_upstream(upstream_id, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase, MockExecResult};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        routes::api::restricted::nginx::upstream::get_upstream_router,
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ))
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_succeeds_returns_ok() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let existing = upstream::Model {
+            id: up_id,
+            name: "todelete".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_model = upstream_target::Model {
+            id: uuid::Uuid::new_v4(),
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]])
+            .append_exec_results(vec![
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+            ])
+            // additional query result for regenerate_and_apply_config -> generate_config
+            .append_query_results(vec![vec![(existing.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.delete(&format!("/upstreams/{}", up_id)).await;
+
+        res.assert_status_ok();
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_agent_error_returns_internal() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let existing = upstream::Model {
+            id: up_id,
+            name: "todelete".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_model = upstream_target::Model {
+            id: uuid::Uuid::new_v4(),
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]])
+            .append_exec_results(vec![
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+            ])
+            .append_query_results(vec![vec![(existing.clone(), Some(target_model.clone()))]])
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ));
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.delete(&format!("/upstreams/{}", up_id)).await;
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server
+            .delete(&format!("/upstreams/{}", uuid::Uuid::new_v4()))
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_not_found_returns_not_found() {
+        let empty_results: Vec<Vec<upstream::Model>> = vec![Vec::<upstream::Model>::new()];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(empty_results)
+            .into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server
+            .delete(&format!("/upstreams/{}", uuid::Uuid::new_v4()))
+            .await;
+
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/remove_upstream_target.rs

@@ -0,0 +1,230 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, State},
+    response::Result as AxumResult,
+};
+use sea_orm::TransactionTrait;
+use uuid::Uuid;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{AppState, api::openapi::tag::NGINX_TAG},
+};
+
+#[utoipa::path(
+    delete,
+    path = "/api/nginx/upstream_targets/{upstream_target_id}",
+    responses(
+        (status = 200, description = "Upstream target removed successfully", body = ()),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Not found"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn remove_upstream_target(
+    _request_info: AuthenticatedRequestInfo,
+    Path(upstream_target_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+) -> AxumResult<Json<()>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+
+    let mut tx = state.database_connection.begin().await?;
+    upstream_service
+        .delete_upstream_target(upstream_target_id, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase, MockExecResult};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        routes::api::restricted::nginx::upstream::get_upstream_router,
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ))
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_target_succeeds_returns_ok() {
+        let ut_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream_target::Model {
+            id: ut_id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        // first find_by_id, then delete (delete typically doesn't return models)
+        let up_model = upstream::Model {
+            id: current_model.upstream_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let first: Vec<Vec<upstream_target::Model>> = vec![vec![current_model.clone()]];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_exec_results(vec![MockExecResult {
+                rows_affected: 1,
+                last_insert_id: 0,
+            }])
+            // additional query result for regenerate_and_apply_config -> generate_config
+            .append_query_results(vec![vec![(up_model.clone(), Some(current_model.clone()))]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.delete(&format!("/upstream_targets/{}", ut_id)).await;
+
+        res.assert_status_ok();
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_target_agent_error_returns_internal() {
+        let ut_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream_target::Model {
+            id: ut_id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = upstream::Model {
+            id: current_model.upstream_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let first: Vec<Vec<upstream_target::Model>> = vec![vec![current_model.clone()]];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_exec_results(vec![MockExecResult {
+                rows_affected: 1,
+                last_insert_id: 0,
+            }])
+            .append_query_results(vec![vec![(up_model.clone(), Some(current_model.clone()))]])
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ));
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server.delete(&format!("/upstream_targets/{}", ut_id)).await;
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_target_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server
+            .delete(&format!("/upstream_targets/{}", uuid::Uuid::new_v4()))
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+
+    #[tokio::test]
+    async fn handler_remove_upstream_target_not_found_returns_not_found() {
+        let empty_results: Vec<Vec<upstream_target::Model>> =
+            vec![Vec::<upstream_target::Model>::new()];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(empty_results)
+            .into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let res = server
+            .delete(&format!("/upstream_targets/{}", uuid::Uuid::new_v4()))
+            .await;
+
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/update_upstream.rs

@@ -0,0 +1,318 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, State},
+    response::Result as AxumResult,
+};
+use sea_orm::TransactionTrait;
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{
+        AppState, api::openapi::tag::NGINX_TAG,
+        api::restricted::nginx::upstream::info::response::UpdateUpstreamInfoResponse,
+    },
+    services::nginx::info::upstream::UpdateUpstreamInfo,
+};
+
+#[derive(Deserialize, utoipa::ToSchema, Serialize)]
+pub struct UpstreamTargetBasicUpdateInfo {
+    pub id: i64,
+    pub enabled: bool,
+}
+
+#[derive(Deserialize, utoipa::ToSchema, Serialize)]
+pub struct UpdateUpstreamRequestBody {
+    pub name: Option<String>,
+    pub protocol: Option<String>,
+    pub algorithm: Option<String>,
+    pub sticky_session: Option<bool>,
+    // only updates upstream targets' enabled status for now
+    pub upstream_targets: Option<Vec<UpstreamTargetBasicUpdateInfo>>,
+}
+
+impl From<UpdateUpstreamRequestBody> for UpdateUpstreamInfo {
+    fn from(val: UpdateUpstreamRequestBody) -> Self {
+        Self {
+            name: val.name,
+            protocol: val.protocol,
+            algorithm: val.algorithm,
+            sticky_session: val.sticky_session,
+            //
+            upstream_targets: None,
+        }
+    }
+}
+
+#[utoipa::path(
+    patch,
+    path = "/api/nginx/upstreams/{upstream_id}",
+    request_body = UpdateUpstreamRequestBody,
+    responses(
+        (status = 200, description = "Upstream updated successfully", body = UpdateUpstreamInfoResponse),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Not found"),
+        (status = 422, description = "Invalid request"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn update_upstream(
+    _request_info: AuthenticatedRequestInfo,
+    Path(upstream_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+    Json(payload): Json<UpdateUpstreamRequestBody>,
+) -> AxumResult<Json<UpdateUpstreamInfoResponse>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+    let update_info: UpdateUpstreamInfo = payload.into();
+
+    let mut tx = state.database_connection.begin().await?;
+    let r = upstream_service
+        .update_upstream(upstream_id, update_info, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(r.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use super::UpdateUpstreamRequestBody;
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        routes::api::restricted::nginx::upstream::get_upstream_router,
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+        get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ))
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_succeeds_returns_ok() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream::Model {
+            id: up_id,
+            name: "old_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let updated_model = upstream::Model {
+            id: up_id,
+            name: "updated_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        // first find_by_id, then update returns updated model
+        let up_model = current_model.clone();
+        let first: Vec<Vec<upstream::Model>> = vec![vec![current_model.clone()]];
+        let second: Vec<Vec<upstream::Model>> = vec![vec![updated_model.clone()]];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_query_results(second)
+            // additional query result for regenerate_and_apply_config -> generate_config
+            .append_query_results(vec![vec![(
+                up_model.clone(),
+                Option::<upstream_target::Model>::None,
+            )]])
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamRequestBody {
+            name: Some("updated_upstream".to_string()),
+            protocol: None,
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: None,
+        };
+
+        let res = server
+            .patch(&format!("/upstreams/{}", up_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status_ok();
+        let text = res.text();
+        let body: crate::routes::api::restricted::nginx::upstream::info::response::UpdateUpstreamInfoResponse =
+            serde_json::from_str(&text).expect("failed to parse json");
+
+        assert_eq!(body.id, up_id);
+        assert_eq!(body.name, "updated_upstream");
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_agent_error_returns_internal() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream::Model {
+            id: up_id,
+            name: "old_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let updated_model = upstream::Model {
+            id: up_id,
+            name: "updated_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: Some(uuid::Uuid::new_v4()),
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = current_model.clone();
+
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let first: Vec<Vec<upstream::Model>> = vec![vec![current_model.clone()]];
+        let second: Vec<Vec<upstream::Model>> = vec![vec![updated_model.clone()]];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_query_results(second)
+            .append_query_results(vec![vec![(
+                up_model.clone(),
+                Option::<upstream_target::Model>::None,
+            )]])
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = get_upstream_router(state).layer(axum::middleware::from_fn(
+            crate::middlewares::require_auth::mock::mock_require_auth,
+        ));
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamRequestBody {
+            name: Some("updated_upstream".to_string()),
+            protocol: None,
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: None,
+        };
+
+        let res = server
+            .patch(&format!("/upstreams/{}", up_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamRequestBody {
+            name: Some("updated_upstream".to_string()),
+            protocol: None,
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: None,
+        };
+
+        let res = server
+            .patch(&format!("/upstreams/{}", uuid::Uuid::new_v4()))
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_not_found_returns_not_found() {
+        let empty_results: Vec<Vec<upstream::Model>> = vec![Vec::<upstream::Model>::new()];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(empty_results)
+            .into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamRequestBody {
+            name: Some("updated_upstream".to_string()),
+            protocol: None,
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: None,
+        };
+
+        let res = server
+            .patch(&format!("/upstreams/{}", uuid::Uuid::new_v4()))
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+}

apps/api/src/routes/api/restricted/nginx/upstream/update_upstream_target.rs

@@ -0,0 +1,348 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::{Path, State},
+    response::Result as AxumResult,
+};
+use sea_orm::TransactionTrait;
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::{
+    errors::api_error::ApiError,
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{
+        AppState, api::openapi::tag::NGINX_TAG,
+        api::restricted::nginx::upstream::info::response::UpdateUpstreamTargetInfoResponse,
+    },
+    services::nginx::info::upstream_target::UpdateUpstreamTargetInfo,
+};
+
+#[derive(Deserialize, utoipa::ToSchema, Serialize)]
+pub struct UpdateUpstreamTargetRequestBody {
+    pub host: Option<String>,
+    pub port: Option<i64>,
+    pub enabled: Option<bool>,
+    pub is_backup: Option<bool>,
+    pub weight: Option<i32>,
+}
+
+impl From<UpdateUpstreamTargetRequestBody> for UpdateUpstreamTargetInfo {
+    fn from(val: UpdateUpstreamTargetRequestBody) -> Self {
+        Self {
+            target_host: val.host,
+            target_port: val.port,
+            enabled: val.enabled,
+            is_backup: val.is_backup,
+            weight: val.weight.map(|w| w as i64),
+        }
+    }
+}
+
+#[utoipa::path(
+    patch,
+    path = "/api/nginx/upstream_targets/{upstream_target_id}",
+    request_body = UpdateUpstreamTargetRequestBody,
+    responses(
+        (status = 200, description = "Upstream target updated successfully", body = UpdateUpstreamTargetInfoResponse),
+        (status = 401, description = "Unauthorized"),
+        (status = 404, description = "Not found"),
+        (status = 422, description = "Invalid request"),
+        (status = 500, description = "Internal server error"),
+    ),
+    tag = NGINX_TAG,
+)]
+pub async fn update_upstream_target(
+    _request_info: AuthenticatedRequestInfo,
+    Path(upstream_target_id): Path<Uuid>,
+    State(state): State<Arc<AppState>>,
+    Json(payload): Json<UpdateUpstreamTargetRequestBody>,
+) -> AxumResult<Json<UpdateUpstreamTargetInfoResponse>, ApiError> {
+    let upstream_service = &state.service.nginx.get_upstream_service();
+    let update_info: UpdateUpstreamTargetInfo = payload.into();
+
+    let mut tx = state.database_connection.begin().await?;
+    let r = upstream_service
+        .update_upstream_target(upstream_target_id, update_info, Some(&mut tx))
+        .await?;
+
+    state
+        .service
+        .nginx
+        .regenerate_and_apply_config(state.service.agent_client.clone(), Some(&mut tx))
+        .await?;
+
+    tx.commit().await?;
+
+    Ok(Json(r.into()))
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use axum::http::StatusCode;
+    use axum::routing::patch;
+    use axum_test::TestServer;
+    use sea_orm::{DatabaseBackend, DatabaseConnection, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    use super::UpdateUpstreamTargetRequestBody;
+    use crate::{
+        configs::{FromConfig, ProgramSettings},
+        middlewares::require_auth::mock::REQUEST_AUTH_USER_INVALID_HEADER,
+        services::{agent_client::MockAgentService, get_mock_app_service},
+    };
+
+    fn get_router_with_state(db: DatabaseConnection) -> axum::Router {
+        let program_settings = ProgramSettings::mock();
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| Ok(()));
+        let mock_agent = Arc::new(mock);
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        axum::Router::new()
+            .route(
+                "/upstream_targets/{upstream_target_id}",
+                patch(crate::routes::api::restricted::nginx::upstream::update_upstream_target::update_upstream_target),
+            )
+            .with_state(state)
+            .layer(axum::middleware::from_fn(
+                crate::middlewares::require_auth::mock::mock_require_auth,
+            ))
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_target_succeeds_returns_ok() {
+        let target_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let updated_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: current_model.upstream_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8081,
+            weight: 2,
+            is_backup: false,
+            enabled: false,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = upstream::Model {
+            id: current_model.upstream_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let first: Vec<Vec<upstream_target::Model>> = vec![vec![current_model.clone()]];
+        let second: Vec<Vec<upstream_target::Model>> = vec![vec![updated_model.clone()]];
+        // additional query result for regenerate_and_apply_config -> generate_config
+        let third: Vec<Vec<(upstream::Model, Option<upstream_target::Model>)>> =
+            vec![vec![(up_model.clone(), Some(updated_model.clone()))]];
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_query_results(second)
+            .append_query_results(third)
+            .into_connection();
+
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamTargetRequestBody {
+            host: None,
+            port: Some(8081),
+            enabled: Some(false),
+            is_backup: None,
+            weight: Some(2),
+        };
+
+        let res = server
+            .patch(&format!("/upstream_targets/{}", target_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status_ok();
+        let text = res.text();
+        let body: crate::routes::api::restricted::nginx::upstream::info::response::UpdateUpstreamTargetInfoResponse =
+            serde_json::from_str(&text).expect("failed to parse json");
+
+        assert_eq!(body.id, target_id);
+        assert_eq!(body.port, 8081);
+        assert!(!body.enabled);
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_target_unauthenticated_returns_unauthorized() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite).into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamTargetRequestBody {
+            host: None,
+            port: Some(8081),
+            enabled: Some(false),
+            is_backup: None,
+            weight: Some(2),
+        };
+
+        let res = server
+            .patch(&format!("/upstream_targets/{}", uuid::Uuid::new_v4()))
+            .add_header(REQUEST_AUTH_USER_INVALID_HEADER, "true")
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::UNAUTHORIZED);
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_target_not_found_returns_not_found() {
+        let empty_results: Vec<Vec<upstream_target::Model>> =
+            vec![Vec::<upstream_target::Model>::new()];
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(empty_results)
+            .into_connection();
+        let router = get_router_with_state(db.clone());
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamTargetRequestBody {
+            host: None,
+            port: Some(8081),
+            enabled: Some(false),
+            is_backup: None,
+            weight: Some(2),
+        };
+
+        let res = server
+            .patch(&format!("/upstream_targets/{}", uuid::Uuid::new_v4()))
+            .json(&payload)
+            .await;
+
+        res.assert_status(StatusCode::NOT_FOUND);
+    }
+
+    #[tokio::test]
+    async fn handler_update_upstream_target_agent_error_returns_internal() {
+        let target_id = uuid::Uuid::new_v4();
+
+        let current_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let updated_model = upstream_target::Model {
+            id: target_id,
+            upstream_id: current_model.upstream_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8081,
+            weight: 2,
+            is_backup: false,
+            enabled: false,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let up_model = upstream::Model {
+            id: current_model.upstream_id,
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let mut mock = MockAgentService::new();
+        mock.expect_validate().returning(|_cfg| Ok(()));
+        mock.expect_apply().returning(|_cfg| {
+            Err(
+                crate::services::agent_client::AgentError::ApplicationFailed(
+                    "internal".to_string(),
+                    "Failed to communicate with the agent.".to_string(),
+                ),
+            )
+        });
+        let mock_agent = Arc::new(mock);
+
+        let first: Vec<Vec<upstream_target::Model>> = vec![vec![current_model.clone()]];
+        let second: Vec<Vec<upstream_target::Model>> = vec![vec![updated_model.clone()]];
+        let third: Vec<Vec<(upstream::Model, Option<upstream_target::Model>)>> =
+            vec![vec![(up_model.clone(), Some(updated_model.clone()))]];
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(first)
+            .append_query_results(second)
+            .append_query_results(third)
+            .into_connection();
+
+        let program_settings = ProgramSettings::mock();
+        let app_service =
+            get_mock_app_service(&Arc::new(db.clone()), &program_settings, mock_agent);
+        let state = Arc::new(crate::routes::AppState {
+            database_connection: Arc::new(db),
+            service: Arc::new(app_service),
+            config: Arc::new(program_settings),
+        });
+
+        let router = axum::Router::new()
+            .route(
+                "/upstream_targets/{upstream_target_id}",
+                axum::routing::patch(crate::routes::api::restricted::nginx::upstream::update_upstream_target::update_upstream_target),
+            )
+            .with_state(state)
+            .layer(axum::middleware::from_fn(
+                crate::middlewares::require_auth::mock::mock_require_auth,
+            ));
+
+        let server = TestServer::new(router).expect("failed to create test server");
+
+        let payload = UpdateUpstreamTargetRequestBody {
+            host: None,
+            port: Some(8081),
+            enabled: Some(false),
+            is_backup: None,
+            weight: Some(2),
+        };
+
+        let res = server
+            .patch(&format!("/upstream_targets/{}", target_id))
+            .json(&payload)
+            .await;
+
+        res.assert_status(axum::http::StatusCode::INTERNAL_SERVER_ERROR);
+    }
+}

apps/api/src/routes/api/restricted/user.rs

@@ -0,0 +1,13 @@
+pub mod me;
+
+use std::sync::Arc;
+
+use axum::Router;
+
+use crate::routes::AppState;
+
+pub fn get_user_router(state: Arc<AppState>) -> Router {
+    Router::new()
+        .route("/me", axum::routing::get(me::get_user_info))
+        .with_state(state)
+}

apps/api/src/routes/api/restricted/user/me.rs

@@ -0,0 +1,58 @@
+use std::sync::Arc;
+
+use axum::{
+    Json,
+    extract::State,
+    http::StatusCode,
+    response::{IntoResponse, Response},
+};
+use serde::{Deserialize, Serialize};
+use tracing::error;
+
+use crate::{
+    middlewares::request_info::AuthenticatedRequestInfo,
+    routes::{AppState, api::openapi::tag::USER_TAG},
+};
+
+/// System health information
+#[derive(Serialize, Deserialize, utoipa::ToSchema)]
+pub struct UserInfo {
+    /// User ID
+    pub id: uuid::Uuid,
+    /// Username
+    pub username: String,
+}
+
+/// Get current user information
+///
+/// Returns the information of the currently authenticated user.
+#[utoipa::path(
+        get,
+        path = "/api/user/me",
+        responses(
+            (status = 200, description = "User information retrieved successfully", body = UserInfo),
+            (status = 401, description = "Unauthorized"),
+            (status = 500, description = "Internal server error"),
+        ),
+        tag = USER_TAG,
+    )]
+pub async fn get_user_info(
+    State(app_state): State<Arc<AppState>>,
+    request_info: AuthenticatedRequestInfo,
+) -> Response {
+    let user_id = request_info.user_id;
+
+    match app_state.service.user.get_user_by_id(user_id, None).await {
+        Ok(user) => {
+            let user_info = UserInfo {
+                id: user.id,
+                username: user.username,
+            };
+            (StatusCode::OK, Json(user_info)).into_response()
+        }
+        Err(err) => {
+            error!("Error fetching user info: {}", err);
+            (StatusCode::INTERNAL_SERVER_ERROR).into_response()
+        }
+    }
+}

apps/api/src/services.rs

@@ -1 +1,85 @@
+pub mod agent_client;
+pub mod auth;
+pub mod nginx;
+pub mod server_state;
 pub mod settings;
+
+use std::sync::Arc;
+
+use ::agent_client::apis::configuration::Configuration;
+
+#[cfg(test)]
+use crate::services::agent_client::MockAgentService;
+use crate::{
+    configs::ProgramSettings,
+    routes::{self, AuthState},
+    services::{
+        agent_client::{AgentService, AgentServiceImpl},
+        auth::{
+            authentication::{AuthenticationServiceImpl, strategies::password::PasswordStrategy},
+            user::{UserService, UserServiceImpl},
+        },
+        nginx::NginxService,
+        server_state::{ServerStateService, ServerStateStore},
+        settings::{SettingsService, SettingsStore},
+    },
+};
+
+pub type ServiceState<T> = Arc<T>;
+
+pub struct AppService {
+    pub settings: ServiceState<dyn SettingsStore>,
+    pub auth_state: AuthState,
+    pub user: ServiceState<dyn UserService>,
+    pub server_state: ServiceState<dyn ServerStateStore>,
+    #[allow(dead_code)]
+    pub nginx: ServiceState<NginxService>,
+    #[allow(dead_code)]
+    pub agent_client: ServiceState<dyn AgentService>,
+}
+
+pub fn get_app_service(
+    db_connection: &Arc<sea_orm::DatabaseConnection>,
+    settings: &ProgramSettings,
+) -> AppService {
+    AppService {
+        server_state: Arc::new(ServerStateService::new(db_connection.clone())),
+        settings: Arc::new(SettingsService::new(db_connection.clone())),
+        auth_state: routes::AuthState {
+            strategy: routes::AuthStrategy {
+                password: Arc::new(PasswordStrategy::new(db_connection.clone())),
+            },
+            authentication: Arc::new(AuthenticationServiceImpl::new(
+                settings.auth.jwt_secret.clone(),
+            )),
+        },
+        user: Arc::new(UserServiceImpl::new(db_connection.clone())),
+        nginx: Arc::new(NginxService::new(db_connection.clone())),
+        agent_client: Arc::new(AgentServiceImpl::new(Configuration::from(
+            settings.agent.clone(),
+        ))),
+    }
+}
+
+#[cfg(test)]
+pub fn get_mock_app_service(
+    db_connection: &Arc<sea_orm::DatabaseConnection>,
+    settings: &ProgramSettings,
+    mock_agent: Arc<MockAgentService>,
+) -> AppService {
+    AppService {
+        server_state: Arc::new(ServerStateService::new(db_connection.clone())),
+        settings: Arc::new(SettingsService::new(db_connection.clone())),
+        auth_state: routes::AuthState {
+            strategy: routes::AuthStrategy {
+                password: Arc::new(PasswordStrategy::new(db_connection.clone())),
+            },
+            authentication: Arc::new(AuthenticationServiceImpl::new(
+                settings.auth.jwt_secret.clone(),
+            )),
+        },
+        user: Arc::new(UserServiceImpl::new(db_connection.clone())),
+        nginx: Arc::new(NginxService::new(db_connection.clone())),
+        agent_client: mock_agent,
+    }
+}

apps/api/src/services/agent_client.rs

@@ -0,0 +1,263 @@
+use std::{os::unix::fs::FileTypeExt, sync::Arc};
+
+use agent_client::{
+    apis::{
+        Api, ApiClient, Error as ApiError, ResponseContent,
+        configuration::Configuration,
+        nginx_agent_api::{ValidateAndReloadParams, ValidateParams, WriteConfigParams},
+    },
+    models::{ValidateAndReloadBody, ValidateBody, WriteConfigBody},
+};
+use tracing::{error, warn};
+
+use crate::{configs::agent::AgentSettings, errors::service_error::ServiceError};
+
+#[derive(Debug)]
+pub enum AgentError {
+    // (internal messages, user-facing messages)
+    #[allow(dead_code)]
+    ValidationFailed(String, String),
+    // (internal messages, user-facing messages)
+    ApplicationFailed(String, String),
+}
+
+impl From<AgentError> for ServiceError {
+    fn from(err: AgentError) -> Self {
+        error!("Agent error occurred: {:?}", err);
+        match err {
+            AgentError::ValidationFailed(_internal, user) => ServiceError::InternalError(user),
+            AgentError::ApplicationFailed(_internal, user) => ServiceError::InternalError(user),
+        }
+    }
+}
+
+impl<T: std::fmt::Debug> From<ResponseContent<T>> for AgentError {
+    fn from(err: ResponseContent<T>) -> Self {
+        let ResponseContent {
+            status,
+            content,
+            entity,
+        } = err;
+        {
+            let entity_str = entity
+                .map(|e| format!("{:?}", e))
+                .unwrap_or_else(|| "<empty>".to_string());
+            AgentError::ApplicationFailed(
+                format!(
+                    "Agent responded with error status {}: {}, entity: {}",
+                    status, content, entity_str
+                ),
+                "Agent reported an error during operation.".to_string(),
+            )
+        }
+    }
+}
+
+impl<T: std::fmt::Debug> From<ApiError<T>> for AgentError {
+    fn from(err: ApiError<T>) -> Self {
+        match err {
+            ApiError::ResponseError(resp) => AgentError::from(resp),
+            ApiError::Io(err) => AgentError::ApplicationFailed(
+                format!("IO error during agent communication: {}", err),
+                "Failed to communicate with the agent.".to_string(),
+            ),
+            ApiError::Reqwest(err) => AgentError::ApplicationFailed(
+                format!("Reqwest error during agent communication: {}", err),
+                "Failed to communicate with the agent.".to_string(),
+            ),
+            ApiError::Serde(err) => AgentError::ApplicationFailed(
+                format!("Serialization error during agent communication: {}", err),
+                "Failed to communicate with the agent.".to_string(),
+            ),
+        }
+    }
+}
+
+#[cfg_attr(test, mockall::automock)]
+#[async_trait::async_trait]
+pub trait AgentService: Send + Sync {
+    #[allow(dead_code)]
+    fn get_client(&self) -> Arc<ApiClient>;
+
+    // TODO: improve error handling and reporting, error reasons
+    // validate configurations that has been created/updated before the given timestamp
+    #[allow(dead_code)]
+    async fn validate(&self, config: &str) -> Result<(), AgentError>;
+    // validate and apply configurations that has been created/updated before the given timestamp
+    async fn apply(&self, config: &str) -> Result<(), AgentError>;
+}
+
+pub struct AgentServiceImpl {
+    client: Arc<ApiClient>,
+}
+
+impl AgentServiceImpl {
+    pub fn new(config: impl Into<Arc<Configuration>>) -> Self {
+        let client = ApiClient::new(config.into());
+        AgentServiceImpl {
+            client: Arc::new(client),
+        }
+    }
+}
+
+impl From<AgentSettings> for Configuration {
+    fn from(settings: AgentSettings) -> Self {
+        let mut config = Configuration::default();
+        let mut builder = reqwest::Client::builder();
+
+        let url = settings.socket_path;
+        // check if the url is a unix socket path
+        let is_socket = std::fs::metadata(&url).is_ok_and(|m| m.file_type().is_socket());
+        if is_socket || url.starts_with("unix://") {
+            builder = builder.unix_socket(url.to_string());
+            config.client = builder.build().expect("Failed to build reqwest client");
+        } else {
+            warn!("AgentSettings contains a non-unix socket path: {}", url);
+            config.base_path = url;
+        }
+
+        config
+    }
+}
+
+#[async_trait::async_trait]
+impl AgentService for AgentServiceImpl {
+    fn get_client(&self) -> Arc<ApiClient> {
+        Arc::clone(&self.client)
+    }
+
+    async fn validate(&self, config: &str) -> Result<(), AgentError> {
+        let timestamp = chrono::Utc::now().timestamp_millis();
+        let name = Self::get_config_name(true);
+        self._validate(&name, timestamp, config).await
+    }
+
+    async fn apply(&self, config: &str) -> Result<(), AgentError> {
+        let timestamp = chrono::Utc::now().timestamp_millis();
+        let name = Self::get_config_name(false);
+        self._validate(&name, timestamp, config).await?;
+        self._apply(&name, timestamp).await
+    }
+}
+
+impl AgentServiceImpl {
+    fn get_config_name(is_validate_only: bool) -> String {
+        format!(
+            "nginx_config_{}{}",
+            if is_validate_only {
+                "validation_"
+            } else {
+                "application_"
+            },
+            uuid::Uuid::new_v4()
+        )
+    }
+
+    async fn _validate(&self, name: &str, timestamp: i64, config: &str) -> Result<(), AgentError> {
+        let api = self.client.nginx_agent_api();
+
+        api.write_config(WriteConfigParams {
+            write_config_body: WriteConfigBody {
+                config_name: name.to_string(),
+                content: config.to_string(),
+                timestamp,
+            },
+        })
+        .await?;
+
+        api.validate(ValidateParams {
+            validate_body: ValidateBody {
+                config_name: name.to_string(),
+                timestamp,
+            },
+        })
+        .await?;
+
+        Ok(())
+    }
+
+    async fn _apply(&self, name: &str, timestamp: i64) -> Result<(), AgentError> {
+        let api = self.client.nginx_agent_api();
+        api.validate_and_reload(ValidateAndReloadParams {
+            validate_and_reload_body: ValidateAndReloadBody {
+                config_name: name.to_string(),
+                timestamp,
+            },
+        })
+        .await?;
+
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use agent_client::{
+        apis::{Api, nginx_agent_api::StatusSuccess},
+        models::StatusResp,
+    };
+    use axum::{http::StatusCode, response::Json};
+    use std::time::Duration;
+    use tempfile::tempdir;
+    use tokio::time::sleep;
+
+    #[test]
+    fn test_agent_service_creation() {
+        let config = Configuration::default();
+        let service = AgentServiceImpl::new(config);
+        let client = service.get_client();
+        assert!(Arc::ptr_eq(&client, &service.client));
+    }
+
+    #[tokio::test]
+    async fn test_agent_socket_support() {
+        // create temporary socket path
+        let dir = tempdir().expect("Failed to create temp dir");
+        let socket_path = dir.path().join("agent.sock");
+
+        // create axum app with a simple /status route
+        let app = axum::Router::new().route(
+            "/status",
+            axum::routing::get(|| async {
+                let result: (StatusCode, StatusResp) = (StatusCode::OK, StatusResp { ok: true });
+
+                (result.0, Json(result.1))
+            }),
+        );
+
+        // bind tokio unix listener and serve in background
+        let listener =
+            tokio::net::UnixListener::bind(&socket_path).expect("Failed to bind to unix socket");
+        let server_fut = axum::serve::serve(listener, app);
+        let _srv = tokio::spawn(async move {
+            let _ = server_fut.await;
+        });
+
+        // give server a moment to start
+        sleep(Duration::from_millis(50)).await;
+
+        let client: ApiClient = ApiClient::new(Arc::new(Configuration {
+            base_path: "http://localhost".to_string(),
+            client: reqwest::Client::builder()
+                .unix_socket(socket_path.clone())
+                .build()
+                .expect("Failed to build reqwest client"),
+            ..Default::default()
+        }));
+
+        let res = client
+            .nginx_agent_api()
+            .status()
+            .await
+            .expect("Failed to get status");
+        let body = res.entity.expect("Response entity is missing");
+
+        assert!(res.status.is_success());
+        if let StatusSuccess::Status200(body) = body {
+            assert!(body.ok);
+        } else {
+            panic!("Unexpected response body");
+        }
+    }
+}

apps/api/src/services/auth.rs

@@ -0,0 +1,2 @@
+pub mod authentication;
+pub mod user;

apps/api/src/services/auth/authentication.rs

@@ -0,0 +1,319 @@
+pub mod strategies;
+
+use std::{collections::HashSet, sync::Arc};
+
+use argon2::password_hash::{SaltString, rand_core::OsRng};
+use jsonwebtoken::{
+    DecodingKey, EncodingKey, Header, Validation, decode, encode,
+    errors::ErrorKind::{ExpiredSignature, InvalidSignature, InvalidSubject, InvalidToken},
+};
+use sea_orm::prelude::Uuid;
+use serde::{Deserialize, Serialize};
+use tokio::sync::RwLock;
+
+use crate::errors::service_error::ServiceError;
+
+// Number of requests between invalidation cache cleanups
+#[allow(dead_code)] // TODO: remove when used
+const INVALIDATE_CACHE_CLEANUP_INTERVAL_REQUESTS: usize = 100; // Cleanup every 100 for invalidation checks
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct Claims {
+    // Subject - user ID
+    pub sub: String,
+    // Issued at as UNIX timestamp
+    pub iat: u64,
+    // Expiration time as UNIX timestamp
+    pub exp: u64,
+}
+
+#[async_trait::async_trait]
+pub trait AuthenticationService: Send + Sync {
+    async fn generate_jwt(
+        &self,
+        user_id: Uuid,
+        duration_secs: u64,
+    ) -> Result<(String, Claims), ServiceError>;
+    async fn is_valid_jwt(
+        &self,
+        token: &str,
+        target_sub: Option<String>,
+    ) -> Result<Option<Claims>, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn parse_jwt(&self, token: &str) -> Result<Claims, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn invalidate_jwt(&self, token: &str) -> Result<(), ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn refresh_jwt(&self, token: &str, duration_secs: u64) -> Result<String, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn logout(&self, token: &str) -> Result<(), ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn cleanup_invalidation_cache(&self);
+}
+
+#[derive(Eq, Hash, PartialEq)]
+struct InvalidationEntry {
+    token: String,
+    invalidated_at: u64,
+    valid_until: u64,
+}
+
+pub struct AuthenticationServiceImpl {
+    secret: String,
+    #[allow(dead_code)] // TODO: remove when used
+    invalidation_cache: Arc<RwLock<HashSet<InvalidationEntry>>>,
+    #[allow(dead_code)] // TODO: remove when used
+    cache_cleanup_counter: Arc<RwLock<usize>>,
+}
+
+impl AuthenticationServiceImpl {
+    pub fn new(secret: Option<String>) -> Self {
+        let secret = secret.unwrap_or_else(|| {
+            // generate a random secret if none is provided
+            SaltString::generate(&mut OsRng).as_str().to_owned()
+        });
+
+        Self {
+            secret,
+            invalidation_cache: Arc::new(RwLock::new(HashSet::new())),
+            cache_cleanup_counter: Arc::new(RwLock::new(0)),
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl AuthenticationService for AuthenticationServiceImpl {
+    async fn generate_jwt(
+        &self,
+        user_id: Uuid,
+        duration_secs: u64,
+    ) -> Result<(String, Claims), ServiceError> {
+        let header = Header::default();
+        let expiration = chrono::Utc::now()
+            .checked_add_signed(chrono::Duration::seconds(duration_secs as i64))
+            .ok_or(ServiceError::InternalError(
+                "Invalid expiration time".into(),
+            ))?
+            .timestamp() as u64;
+        let claims = Claims {
+            sub: user_id.to_string(),
+            iat: chrono::Utc::now().timestamp() as u64,
+            exp: expiration,
+        };
+        let token = encode(
+            &header,
+            &claims,
+            &EncodingKey::from_secret(self.secret.as_ref()),
+        )
+        .map_err(|e| ServiceError::InternalError(format!("JWT generation error: {}", e)))?;
+        Ok((token, claims))
+    }
+
+    async fn is_valid_jwt(
+        &self,
+        token: &str,
+        target_sub: Option<String>,
+    ) -> Result<Option<Claims>, ServiceError> {
+        let mut validation = Validation::default();
+        // disable leeway for strict expiration checking
+        validation.leeway = 0;
+        if let Some(expected_sub) = target_sub {
+            validation.sub = Some(expected_sub);
+        }
+        let decoding_key = DecodingKey::from_secret(self.secret.as_ref());
+        match decode::<Claims>(token, &decoding_key, &validation) {
+            Ok(data) => Ok(Some(data.claims)),
+            Err(err) => match *err.kind() {
+                InvalidToken | InvalidSubject | ExpiredSignature | InvalidSignature => Ok(None),
+                _ => Err(ServiceError::InternalError(format!(
+                    "JWT validation error: {}",
+                    err
+                ))),
+            },
+        }
+    }
+
+    async fn parse_jwt(&self, token: &str) -> Result<Claims, ServiceError> {
+        let decoding_key = DecodingKey::from_secret(self.secret.as_ref());
+        let token_data = decode::<Claims>(token, &decoding_key, &Validation::default())
+            .map_err(|e| ServiceError::InternalError(format!("JWT parsing error: {}", e)))?;
+        Ok(token_data.claims)
+    }
+
+    async fn invalidate_jwt(&self, token: &str) -> Result<(), ServiceError> {
+        let claims = self.parse_jwt(token).await?;
+        let valid_until = claims.exp;
+        let invalidated_at = chrono::Utc::now().timestamp() as u64;
+        let entry = InvalidationEntry {
+            token: token.to_string(),
+            invalidated_at,
+            valid_until,
+        };
+
+        {
+            self.invalidation_cache.write().await.insert(entry);
+        }
+        //
+        if self.cache_cleanup_counter.read().await.wrapping_add(1)
+            % INVALIDATE_CACHE_CLEANUP_INTERVAL_REQUESTS
+            == 0
+        {
+            self.cleanup_invalidation_cache().await;
+        }
+        //
+        Ok(())
+    }
+
+    async fn refresh_jwt(&self, token: &str, duration_secs: u64) -> Result<String, ServiceError> {
+        let claims = self.parse_jwt(token).await?;
+        let user_id = Uuid::parse_str(&claims.sub).map_err(|e| {
+            ServiceError::InternalError(format!("Invalid user ID in JWT claims: {}", e))
+        })?;
+        let (new_token, _) = self.generate_jwt(user_id, duration_secs).await?;
+        Ok(new_token)
+    }
+
+    async fn logout(&self, token: &str) -> Result<(), ServiceError> {
+        self.invalidate_jwt(token).await
+    }
+
+    async fn cleanup_invalidation_cache(&self) {
+        let now = chrono::Utc::now().timestamp() as u64;
+        let mut cache = self.invalidation_cache.write().await;
+        cache.retain(|entry| entry.valid_until > now);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::time::{Duration, sleep};
+
+    #[tokio::test]
+    async fn test_jwt_generation_and_validation() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let user_id = Uuid::new_v4();
+        let (token, _) = service
+            .generate_jwt(user_id, 60)
+            .await
+            .expect("Failed to generate jwt");
+
+        let valid = service
+            .is_valid_jwt(&token, None)
+            .await
+            .expect("Failed to validate jwt");
+        assert!(valid.is_some(), "Generated token should be valid");
+        let claims = service
+            .parse_jwt(&token)
+            .await
+            .expect("Failed to parse jwt");
+        assert_eq!(claims.sub, user_id.to_string());
+    }
+
+    #[tokio::test]
+    async fn test_jwt_validation_with_wrong_subject() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let user_id = Uuid::new_v4();
+        let (token, _) = service
+            .generate_jwt(user_id, 60)
+            .await
+            .expect("Failed to generate jwt");
+
+        let other_sub = Uuid::new_v4().to_string();
+        let valid = service
+            .is_valid_jwt(&token, Some(other_sub))
+            .await
+            .expect("jwt is not valid");
+        assert!(
+            valid.is_none(),
+            "Token should be invalid for a different subject"
+        );
+    }
+
+    #[tokio::test]
+    async fn test_parse_jwt_invalid_token() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let res = service.parse_jwt("not_a_token").await;
+        assert!(matches!(res, Err(ServiceError::InternalError(_))));
+    }
+
+    #[tokio::test]
+    async fn test_refresh_jwt() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let user_id = Uuid::new_v4();
+        let (token, _) = service
+            .generate_jwt(user_id, 60)
+            .await
+            .expect("Failed to generate jwt");
+        let new_token = service
+            .refresh_jwt(&token, 120)
+            .await
+            .expect("Failed to refresh jwt");
+
+        let claims = service
+            .parse_jwt(&new_token)
+            .await
+            .expect("Failed to parse refreshed jwt");
+        assert_eq!(claims.sub, user_id.to_string());
+        assert_eq!(claims.exp - claims.iat, 120);
+    }
+
+    #[tokio::test]
+    async fn test_is_valid_jwt_expired() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let user_id = Uuid::new_v4();
+        let (token, claims) = service
+            .generate_jwt(user_id, 1)
+            .await
+            .expect("Failed to generate jwt");
+        sleep(Duration::from_secs(2)).await;
+
+        let valid = service
+            .is_valid_jwt(&token, None)
+            .await
+            .expect("Failed to validate jwt");
+        assert!(
+            valid.is_none(),
+            "Token should be expired and thus invalid. Current time: {:?}. Diff: {}",
+            chrono::Utc::now(),
+            chrono::Utc::now().timestamp() - claims.exp as i64
+        );
+    }
+
+    #[tokio::test]
+    async fn test_invalidate_and_cleanup() {
+        let service = AuthenticationServiceImpl::new(Some("secret".to_string()));
+
+        let user_id = Uuid::new_v4();
+        let (token, _) = service
+            .generate_jwt(user_id, 1)
+            .await
+            .expect("Failed to generate jwt");
+
+        service
+            .invalidate_jwt(&token)
+            .await
+            .expect("Failed to invalidate jwt");
+
+        // ensure entry is present
+        {
+            let cache = service.invalidation_cache.read().await;
+            assert!(cache.iter().any(|e| e.token == token));
+        }
+
+        // wait until token validity ends and cleanup
+        sleep(Duration::from_secs(2)).await;
+        service.cleanup_invalidation_cache().await;
+
+        let cache = service.invalidation_cache.read().await;
+        assert!(
+            cache.is_empty(),
+            "Cleanup should remove expired invalidation entries"
+        );
+    }
+}

apps/api/src/services/auth/authentication/strategies.rs

@@ -0,0 +1 @@
+pub mod password;

apps/api/src/services/auth/authentication/strategies/password.rs

@@ -0,0 +1,490 @@
+use std::sync::Arc;
+
+use crate::{errors::service_error::ServiceError, with_conn};
+use argon2::{
+    Argon2,
+    password_hash::{PasswordHash, PasswordHasher, PasswordVerifier, SaltString, rand_core::OsRng},
+};
+use database::generated::entities::{user, user_identity};
+use sea_orm::{
+    ColumnTrait, DatabaseConnection, DatabaseTransaction, EntityTrait, IntoActiveModel,
+    QueryFilter, prelude::Uuid,
+};
+
+pub struct PasswordStrategy {
+    connection: Arc<DatabaseConnection>,
+}
+
+const MAX_PASSWORD_LENGTH: usize = 32;
+const PASSWORD_PROVIDER: &str = "password";
+
+impl PasswordStrategy {
+    pub fn new(connection: Arc<DatabaseConnection>) -> Self {
+        Self { connection }
+    }
+
+    pub async fn authenticate(
+        &self,
+        username: &str,
+        password: &str,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<Uuid, ServiceError> {
+        // Find user by username
+        let user = with_conn!(&*self.connection, tx, conn, {
+            user::Entity::find()
+                .filter(user::Column::Name.eq(username))
+                .one(*conn)
+                .await?
+                .ok_or_else(|| {
+                    ServiceError::Unauthorized("Invalid username or password".to_string())
+                })?
+        });
+        // Get user's identity
+        let identity = with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::find()
+                .filter(user_identity::Column::UserId.eq(user.id))
+                .one(*conn)
+                .await?
+                .ok_or_else(|| {
+                    ServiceError::Unauthorized("Invalid username or password".to_string())
+                })?
+        });
+
+        // Check if revoked
+        if identity.is_revoked {
+            return Err(ServiceError::Unauthorized("Account is revoked".to_string()));
+        }
+
+        // Verify password
+        let password_hash = identity
+            .password_hash
+            .ok_or_else(|| ServiceError::InternalError("Invalid password hash".to_string()))?;
+        let parsed_hash = PasswordHash::new(&password_hash)
+            .map_err(|_| ServiceError::InternalError("Invalid password hash".to_string()))?;
+
+        Argon2::default()
+            .verify_password(password.as_bytes(), &parsed_hash)
+            .map_err(|_| ServiceError::Unauthorized("Invalid username or password".to_string()))?;
+
+        Ok(user.id)
+    }
+    #[allow(dead_code)] // TODO: remove when used
+    pub async fn revoke_identity(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        let mut identity = with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::find()
+                .filter(user_identity::Column::UserId.eq(user_id))
+                .one(*conn)
+                .await?
+                .ok_or_else(|| ServiceError::NotFound("User identity not found".to_string()))?
+        });
+
+        identity.is_revoked = true;
+
+        with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::update(identity.into_active_model())
+                .exec(*conn)
+                .await
+                .map_err(ServiceError::from)
+        })?;
+
+        Ok(())
+    }
+
+    pub async fn create_identity(
+        &self,
+        user_id: Uuid,
+        password: &str,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        Self::is_valid_password(password).map_err(ServiceError::BadRequest)?;
+
+        // If an identity already exists for this user/provider, treat as success.
+        // This also allows tests using MockDatabase to provide a query result
+        // for an existing identity without requiring an insert exec result.
+        let existing = with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::find()
+                .filter(user_identity::Column::UserId.eq(user_id))
+                .filter(user_identity::Column::Provider.eq(PASSWORD_PROVIDER.to_string()))
+                .one(*conn)
+                .await?
+        });
+
+        if existing.is_some() {
+            return Err(ServiceError::BadRequest(
+                "Identity already exists".to_string(),
+            ));
+        }
+
+        let password_hash = Argon2::default()
+            .hash_password(password.as_bytes(), &SaltString::generate(&mut OsRng))
+            .map_err(|_| ServiceError::InternalError("Failed to hash password".to_string()))?
+            .to_string();
+
+        let new_identity = user_identity::ActiveModel {
+            id: sea_orm::ActiveValue::Set(Uuid::new_v4()),
+            user_id: sea_orm::ActiveValue::Set(user_id),
+            provider: sea_orm::ActiveValue::Set(PASSWORD_PROVIDER.to_string()),
+            password_hash: sea_orm::ActiveValue::Set(Some(password_hash)),
+            metadata: sea_orm::ActiveValue::Set(None),
+            is_revoked: sea_orm::ActiveValue::Set(false),
+            ..Default::default()
+        };
+
+        with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::insert(new_identity)
+                .exec(*conn)
+                .await
+                .map_err(ServiceError::from)
+        })?;
+
+        Ok(())
+    }
+    #[allow(dead_code)] // TODO: remove when used
+    pub async fn update_password(
+        &self,
+        user_id: Uuid,
+        new_password: &str,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        Self::is_valid_password(new_password).map_err(ServiceError::BadRequest)?;
+
+        let password_hash = Argon2::default()
+            .hash_password(new_password.as_bytes(), &SaltString::generate(&mut OsRng))
+            .map_err(|_| ServiceError::InternalError("Failed to hash password".to_string()))?
+            .to_string();
+
+        let mut identity = with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::find()
+                .filter(user_identity::Column::UserId.eq(user_id))
+                .one(*conn)
+                .await?
+                .ok_or_else(|| ServiceError::NotFound("User identity not found".to_string()))?
+        });
+
+        identity.password_hash = Some(password_hash);
+        identity.password_changed_at = Some(chrono::Utc::now());
+
+        with_conn!(&*self.connection, tx, conn, {
+            user_identity::Entity::update(identity.into_active_model())
+                .exec(*conn)
+                .await
+                .map_err(ServiceError::from)
+        })?;
+
+        Ok(())
+    }
+
+    fn is_valid_password(password: &str) -> Result<(), String> {
+        if password.is_empty() {
+            return Err("Password cannot be empty".to_string());
+        }
+        if password.len() > MAX_PASSWORD_LENGTH {
+            return Err(format!(
+                "Password cannot be longer than {} characters",
+                MAX_PASSWORD_LENGTH
+            ));
+        }
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use database::generated::entities::{user, user_identity};
+    use sea_orm::MockDatabase;
+
+    #[test]
+    fn ensure_send_sync() {
+        fn assert_send_sync<T: Send + Sync>() {}
+        assert_send_sync::<PasswordStrategy>();
+    }
+
+    #[test]
+    fn password_validation() {
+        let valid_password = "ValidPassword123!";
+        let long_password = "a".repeat(129);
+
+        assert!(PasswordStrategy::is_valid_password(valid_password).is_ok());
+        assert!(PasswordStrategy::is_valid_password(long_password.as_str()).is_err());
+    }
+
+    #[tokio::test]
+    async fn authenticate_user_not_found() {
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy
+            .authenticate("nonexistent_user", "password", None)
+            .await;
+
+        assert!(matches!(result, Err(ServiceError::Unauthorized(_))));
+    }
+
+    #[tokio::test]
+    async fn authenticate_invalid_password() {
+        let user_id = Uuid::new_v4();
+        let password_hash = Argon2::default()
+            .hash_password(
+                "CorrectPassword".as_bytes(),
+                &SaltString::generate(&mut OsRng),
+            )
+            .expect("Failed to hash password")
+            .to_string();
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![user::Model {
+                id: user_id,
+                name: "test_user".to_string(),
+                is_active: true,
+                is_admin: false,
+                created_at: chrono::Utc::now(),
+                updated_at: chrono::Utc::now(),
+                deleted_at: None,
+                last_login_at: None,
+            }]])
+            .append_query_results(vec![vec![user_identity::Model {
+                id: Uuid::new_v4(),
+                user_id,
+                email: None,
+                provider: PASSWORD_PROVIDER.to_string(),
+                password_hash: Some(password_hash),
+                metadata: None,
+                is_revoked: false,
+                revoked_at: None,
+                created_at: chrono::Utc::now(),
+                updated_at: chrono::Utc::now(),
+                password_changed_at: None,
+            }]])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy
+            .authenticate("test_user", "InvalidPassword", None)
+            .await;
+
+        assert!(matches!(result, Err(ServiceError::Unauthorized(_))));
+    }
+
+    #[tokio::test]
+    async fn authenticate_success() {
+        let user_id = Uuid::new_v4();
+        let password_hash = Argon2::default()
+            .hash_password(
+                "CorrectPassword".as_bytes(),
+                &SaltString::generate(&mut OsRng),
+            )
+            .expect("Failed to hash password")
+            .to_string();
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![user::Model {
+                id: user_id,
+                name: "test_user".to_string(),
+                is_active: true,
+                is_admin: false,
+                created_at: chrono::Utc::now(),
+                updated_at: chrono::Utc::now(),
+                deleted_at: None,
+                last_login_at: None,
+            }]])
+            .append_query_results(vec![vec![user_identity::Model {
+                id: Uuid::new_v4(),
+                user_id,
+                email: None,
+                provider: PASSWORD_PROVIDER.to_string(),
+                password_hash: Some(password_hash),
+                metadata: None,
+                is_revoked: false,
+                revoked_at: None,
+                created_at: chrono::Utc::now(),
+                updated_at: chrono::Utc::now(),
+                password_changed_at: None,
+            }]])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy
+            .authenticate("test_user", "CorrectPassword", None)
+            .await;
+
+        assert!(matches!(result, Ok(id) if id == user_id));
+    }
+
+    #[tokio::test]
+    async fn revoke_identity_not_found() {
+        let user_id = Uuid::new_v4();
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy.revoke_identity(user_id, None).await;
+
+        assert!(matches!(result, Err(ServiceError::NotFound(_))));
+    }
+
+    #[tokio::test]
+    async fn revoke_identity_success() {
+        let user_id = Uuid::new_v4();
+        let identity = user_identity::Model {
+            id: Uuid::new_v4(),
+            user_id,
+            email: None,
+            provider: PASSWORD_PROVIDER.to_string(),
+            password_hash: None,
+            metadata: None,
+            is_revoked: false,
+            revoked_at: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+            password_changed_at: None,
+        };
+
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![
+                vec![identity.clone()],
+                vec![user_identity::Model {
+                    is_revoked: true,
+                    ..identity
+                }],
+            ])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy.revoke_identity(user_id, None).await;
+
+        assert!(result.is_ok());
+    }
+
+    #[tokio::test]
+    async fn create_identity_invalid_password() {
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite).into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy.create_identity(Uuid::new_v4(), "", None).await;
+
+        assert!(matches!(result, Err(ServiceError::BadRequest(_))));
+    }
+
+    #[tokio::test]
+    async fn create_identity_success() {
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            // No existing identity
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            // Insert exec result (mock exec result for insert)
+            .append_exec_results(vec![sea_orm::MockExecResult {
+                rows_affected: 1,
+                last_insert_id: 0,
+            }])
+            // Return inserted identity for any subsequent queries
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy
+            .create_identity(Uuid::new_v4(), "ValidPass1!", None)
+            .await;
+
+        assert!(
+            result.is_ok(),
+            "Failed to create identity, error: {:?}",
+            result.err()
+        );
+    }
+
+    #[tokio::test]
+    async fn create_identity_existing() {
+        let user_id = Uuid::new_v4();
+        let identity = user_identity::Model {
+            id: Uuid::new_v4(),
+            user_id,
+            email: None,
+            provider: PASSWORD_PROVIDER.to_string(),
+            password_hash: Some("hash".to_string()),
+            metadata: None,
+            is_revoked: false,
+            revoked_at: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+            password_changed_at: None,
+        };
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![identity]])
+            .into_connection();
+        let strategy = PasswordStrategy::new(Arc::new(db));
+        let result = strategy.create_identity(user_id, "ValidPass1!", None).await;
+        assert!(matches!(result, Err(ServiceError::BadRequest(_))));
+    }
+
+    #[tokio::test]
+    async fn update_password_not_found() {
+        let user_id = Uuid::new_v4();
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy.update_password(user_id, "NewPass1!", None).await;
+
+        assert!(matches!(result, Err(ServiceError::NotFound(_))));
+    }
+
+    #[tokio::test]
+    async fn update_password_success() {
+        let user_id = Uuid::new_v4();
+        let identity = user_identity::Model {
+            id: Uuid::new_v4(),
+            user_id,
+            email: None,
+            provider: PASSWORD_PROVIDER.to_string(),
+            password_hash: Some("old_hash".to_string()),
+            metadata: None,
+            is_revoked: false,
+            revoked_at: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+            password_changed_at: None,
+        };
+
+        let db = MockDatabase::new(sea_orm::DatabaseBackend::Sqlite)
+            .append_query_results(vec![
+                vec![identity],
+                vec![user_identity::Model {
+                    id: Uuid::new_v4(),
+                    user_id,
+                    email: None,
+                    provider: PASSWORD_PROVIDER.to_string(),
+                    password_hash: Some("new_hash".to_string()),
+                    metadata: None,
+                    is_revoked: false,
+                    revoked_at: None,
+                    created_at: chrono::Utc::now(),
+                    updated_at: chrono::Utc::now(),
+                    password_changed_at: None,
+                }],
+            ])
+            .into_connection();
+
+        let strategy = PasswordStrategy::new(Arc::new(db));
+
+        let result = strategy.update_password(user_id, "NewPass1!", None).await;
+
+        assert!(
+            result.is_ok(),
+            "Failed to update password, error: {:?}",
+            result.err()
+        );
+    }
+}

apps/api/src/services/auth/user.rs

@@ -0,0 +1,217 @@
+use std::sync::Arc;
+
+use database::generated::entities::user::{
+    self, ActiveModel as UserActiveModel, Model as UserModel,
+};
+use sea_orm::{
+    ActiveModelTrait, ActiveValue, ColumnTrait, DatabaseConnection, DatabaseTransaction, DbErr,
+    EntityTrait, IntoActiveModel, QueryFilter, prelude::Uuid,
+};
+
+use crate::{errors::service_error::ServiceError, with_conn};
+
+#[async_trait::async_trait]
+pub trait UserService: Send + Sync {
+    async fn get_user_by_id(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn is_admin(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<bool, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn user_exists(
+        &self,
+        username: &str,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<bool, ServiceError>;
+    async fn create_user(
+        &self,
+        user: NewUser,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn update_user(
+        &self,
+        user_id: Uuid,
+        user: UpdateUser,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError>;
+    #[allow(dead_code)] // TODO: remove when used
+    async fn delete_user(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError>;
+}
+
+pub struct User {
+    pub id: Uuid,
+    pub username: String,
+    #[allow(dead_code)] // TODO: remove when used
+    pub is_admin: bool,
+}
+
+impl From<UserModel> for User {
+    fn from(model: UserModel) -> Self {
+        Self {
+            id: model.id,
+            username: model.name,
+            is_admin: model.is_admin,
+        }
+    }
+}
+
+pub struct NewUser {
+    pub username: String,
+    pub is_admin: bool,
+}
+
+pub struct UpdateUser {
+    #[allow(dead_code)] // TODO: remove when used
+    pub username: Option<String>,
+    #[allow(dead_code)] // TODO: remove when used
+    pub is_admin: Option<bool>,
+    #[allow(dead_code)] // TODO: remove when used
+    pub is_active: Option<bool>,
+}
+
+impl UpdateUser {
+    #[allow(dead_code)] // TODO: remove when used
+    fn apply_to_active_model(&self, model: &mut UserActiveModel) {
+        if let Some(username) = &self.username {
+            model.name = ActiveValue::Set(username.clone());
+        }
+        if let Some(is_admin) = self.is_admin {
+            model.is_admin = ActiveValue::Set(is_admin);
+        }
+        if let Some(is_active) = self.is_active {
+            model.is_active = ActiveValue::Set(is_active);
+        }
+    }
+}
+
+pub struct UserServiceImpl {
+    connection: Arc<DatabaseConnection>,
+}
+
+impl UserServiceImpl {
+    pub fn new(connection: Arc<DatabaseConnection>) -> Self {
+        Self { connection }
+    }
+
+    async fn get_user_by_id_from_db(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UserModel, ServiceError> {
+        let user = with_conn!(&*self.connection, tx, conn, {
+            user::Entity::find_by_id(user_id).one(*conn).await
+        });
+
+        match user {
+            Err(err) => Err(ServiceError::from(err)),
+            Ok(None) => Err(ServiceError::NotFound(format!(
+                "User with id '{}' not found",
+                user_id
+            ))),
+            Ok(Some(record)) => Ok(record),
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl UserService for UserServiceImpl {
+    async fn get_user_by_id(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError> {
+        let user = self.get_user_by_id_from_db(user_id, tx).await?;
+        Ok(User::from(user))
+    }
+
+    async fn is_admin(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<bool, ServiceError> {
+        let user = self.get_user_by_id(user_id, tx).await?;
+        Ok(user.is_admin)
+    }
+
+    async fn user_exists(
+        &self,
+        username: &str,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<bool, ServiceError> {
+        let user = with_conn!(&*self.connection, tx, conn, {
+            user::Entity::find()
+                .filter(user::Column::Name.eq(username))
+                .one(*conn)
+                .await
+        });
+
+        match user {
+            Err(err) => match err {
+                DbErr::RecordNotFound(_) => Ok(false),
+                _ => Err(ServiceError::from(err)),
+            },
+            Ok(None) => Ok(false),
+            Ok(Some(_)) => Ok(true),
+        }
+    }
+
+    async fn create_user(
+        &self,
+        user: NewUser,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError> {
+        let user_active_model = UserActiveModel {
+            id: ActiveValue::Set(Uuid::new_v4()),
+            name: ActiveValue::Set(user.username),
+            is_admin: ActiveValue::Set(user.is_admin),
+            is_active: ActiveValue::Set(true),
+            ..Default::default()
+        };
+
+        let user_model = with_conn!(&*self.connection, tx, conn, {
+            user_active_model.insert(*conn).await
+        })?;
+
+        Ok(User::from(user_model))
+    }
+
+    async fn update_user(
+        &self,
+        user_id: Uuid,
+        update_user: UpdateUser,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<User, ServiceError> {
+        let existing_user = self.get_user_by_id_from_db(user_id, tx).await?;
+
+        let mut user_active_model = existing_user.into_active_model();
+        update_user.apply_to_active_model(&mut user_active_model);
+
+        let user_model = user_active_model.update(&*self.connection).await?;
+
+        Ok(User::from(user_model))
+    }
+
+    async fn delete_user(
+        &self,
+        user_id: Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        let user = self.get_user_by_id_from_db(user_id, tx).await?;
+
+        let user_active_model = user.into_active_model();
+        user_active_model.delete(&*self.connection).await?;
+
+        Ok(())
+    }
+}

apps/api/src/services/nginx.rs

@@ -0,0 +1,86 @@
+pub mod builder;
+pub mod info;
+pub mod traits;
+
+pub mod upstream;
+
+use std::sync::Arc;
+
+use sea_orm::{DatabaseConnection, DatabaseTransaction};
+
+use crate::{
+    errors::service_error::ServiceError,
+    services::{
+        agent_client::AgentService,
+        nginx::{
+            builder::{NginxConfigBuilder, NginxConfigProvider},
+            upstream::{UpstreamService, UpstreamServiceImpl},
+        },
+    },
+};
+
+pub struct NginxService {
+    #[allow(dead_code)]
+    connection: Arc<DatabaseConnection>,
+    //
+    upstream_service: Arc<dyn UpstreamService>,
+}
+
+impl NginxService {
+    pub fn new(connection: Arc<DatabaseConnection>) -> Self {
+        Self {
+            connection: connection.clone(),
+            //
+            upstream_service: Arc::new(UpstreamServiceImpl::new(connection.clone())),
+        }
+    }
+
+    pub fn get_upstream_service(&self) -> Arc<dyn UpstreamService> {
+        self.upstream_service.clone()
+    }
+
+    #[allow(dead_code)]
+    pub async fn validate_config(
+        &self,
+        agent: Arc<dyn AgentService>,
+        config: &str,
+    ) -> Result<(), ServiceError> {
+        agent.validate(config).await?;
+
+        Ok(())
+    }
+
+    pub async fn apply_changes(
+        &self,
+        agent: Arc<dyn AgentService>,
+        config: &str,
+    ) -> Result<(), ServiceError> {
+        agent.apply(config).await?;
+
+        Ok(())
+    }
+
+    pub async fn generate_config(
+        &self,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<String, ServiceError> {
+        let mut builder = NginxConfigBuilder::default();
+        self.upstream_service
+            .generate_config(&mut builder, tx)
+            .await?;
+
+        Ok(builder.to_nginx_config(None))
+    }
+
+    pub async fn regenerate_and_apply_config(
+        &self,
+        agent: Arc<dyn AgentService>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        let config = self.generate_config(tx).await?;
+
+        self.apply_changes(agent, &config).await?;
+
+        Ok(())
+    }
+}

apps/api/src/services/nginx/builder.rs

@@ -0,0 +1,43 @@
+use crate::services::nginx::info::upstream::UpstreamInfo;
+
+pub const INDENT_SIZE: usize = 2;
+
+pub trait NginxConfigProvider {
+    fn to_nginx_config(&self, indent: Option<usize>) -> String;
+}
+
+#[derive(Default)]
+pub struct NginxConfigBuilder {
+    upstreams: Vec<UpstreamInfo>,
+}
+
+impl NginxConfigBuilder {
+    pub fn add_upstream(&mut self, upstream: UpstreamInfo) {
+        self.upstreams.push(upstream);
+    }
+
+    pub fn add_upstreams(&mut self, upstreams: Vec<UpstreamInfo>) {
+        for upstream in upstreams {
+            self.add_upstream(upstream);
+        }
+    }
+}
+
+impl NginxConfigProvider for NginxConfigBuilder {
+    fn to_nginx_config(&self, indent: Option<usize>) -> String {
+        let mut config = format!(
+            "# Nginx Config Generated by YANPM at {}",
+            chrono::Utc::now()
+        );
+
+        for upstream in &self.upstreams {
+            config.push('\n');
+            config.push_str(&upstream.to_nginx_config(indent));
+        }
+
+        // TODO: Add other sections like servers, locations, etc.
+        // trailing newline for file ending
+        config.push('\n');
+        config
+    }
+}

apps/api/src/services/nginx/info.rs

@@ -0,0 +1,2 @@
+pub mod upstream;
+pub mod upstream_target;

apps/api/src/services/nginx/info/upstream.rs

@@ -0,0 +1,219 @@
+use chrono::{DateTime, Utc};
+
+use database::generated::entities::{upstream, upstream_target};
+use sea_orm::ActiveValue::{Set, Unchanged};
+use tracing::warn;
+use uuid::Uuid;
+
+use crate::{
+    services::nginx::{
+        builder::{INDENT_SIZE, NginxConfigProvider},
+        info::upstream_target as upstream_target_info,
+        traits::indentable::Indentable,
+    },
+    set_if_some,
+};
+
+const PLACEHOLDER_TARGET: &str = "server 127.0.0.1:65535 down; # placeholder target";
+
+#[derive(Clone)]
+pub struct UpstreamInfo {
+    pub id: Uuid,
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: String,
+    pub sticky_session: bool,
+    pub created_by: Option<Uuid>,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_targets: Vec<upstream_target_info::UpstreamTargetInfo>,
+}
+
+pub struct UpstreamCreateInfo {
+    pub name: String,
+    pub protocol: String,
+    pub algorithm: String,
+    pub sticky_session: bool,
+    pub created_by: Option<Uuid>,
+    //
+    pub upstream_targets: Vec<upstream_target_info::UpstreamTargetCreateInfo>,
+}
+
+#[derive(Clone)]
+pub struct UpdateUpstreamInfo {
+    pub name: Option<String>,
+    pub protocol: Option<String>,
+    pub algorithm: Option<String>,
+    pub sticky_session: Option<bool>,
+    //
+    pub upstream_targets: Option<Vec<(Uuid, bool)>>,
+}
+
+impl NginxConfigProvider for UpstreamInfo {
+    fn to_nginx_config(&self, indent: Option<usize>) -> String {
+        let targets_config: Vec<String> = self
+            .upstream_targets
+            .iter()
+            .map(|target| target.to_nginx_config(Some(indent.unwrap_or(0) + INDENT_SIZE)))
+            .collect();
+
+        let mut targets_config_str = {
+            let config_str = match self.algorithm.as_str() {
+                "least-conn" => "least_conn",
+                "ip-hash" => "ip_hash",
+                "round-robin" => "",
+                v => {
+                    // TODO: allow arbitrary algorithms via config extensions/plugins
+                    warn!(
+                        "Unknown upstream algorithm '{}', defaulting to 'round-robin'",
+                        v
+                    );
+                    ""
+                }
+            }
+            .to_string();
+            // TODO: add support for sticky session / checking for nginx sticky module existence
+            // if self.sticky_session {
+            //   config_str.push_str("sticky")
+            // }
+            if config_str.trim().is_empty() {
+                String::new()
+            } else {
+                config_str + ";"
+            }
+        }
+        .indent(indent.unwrap_or(0) + INDENT_SIZE * 2);
+        targets_config_str.push('\n');
+
+        targets_config_str.push_str(
+            &(if targets_config.is_empty() {
+                // add placeholder if no targets
+                PLACEHOLDER_TARGET.to_string()
+            } else {
+                // normal targets
+                targets_config.join("\n")
+            }
+            .indent(indent.unwrap_or(0) + INDENT_SIZE)),
+        );
+
+        // add placeholder if all targets are backup
+        if self.upstream_targets.iter().all(|v| v.is_backup) {
+            targets_config_str.push('\n');
+            targets_config_str
+                .push_str(&PLACEHOLDER_TARGET.indent(indent.unwrap_or(0) + INDENT_SIZE));
+        }
+
+        format!("upstream {} {{\n{}\n}}", self.name, targets_config_str).indent(indent.unwrap_or(0))
+    }
+}
+
+impl From<UpstreamCreateInfo> for (upstream::ActiveModel, Vec<upstream_target::ActiveModel>) {
+    fn from(val: UpstreamCreateInfo) -> (upstream::ActiveModel, Vec<upstream_target::ActiveModel>) {
+        let upstream_uuid = Uuid::new_v4();
+        let upstream = upstream::ActiveModel {
+            id: sea_orm::ActiveValue::Set(upstream_uuid),
+            name: sea_orm::ActiveValue::Set(val.name),
+            protocol: sea_orm::ActiveValue::Set(val.protocol),
+            algorithm: sea_orm::ActiveValue::Set(val.algorithm),
+            sticky_session: sea_orm::ActiveValue::Set(val.sticky_session),
+            created_by: sea_orm::ActiveValue::Set(val.created_by),
+            created_at: sea_orm::ActiveValue::Set(chrono::Utc::now()),
+            updated_at: sea_orm::ActiveValue::Set(chrono::Utc::now()),
+        };
+        let upstream_targets = val
+            .upstream_targets
+            .into_iter()
+            .map(|target| {
+                let mut active_model: upstream_target::ActiveModel = target.into();
+                active_model.upstream_id = sea_orm::ActiveValue::Set(upstream_uuid);
+                active_model
+            })
+            .collect();
+        (upstream, upstream_targets)
+    }
+}
+
+impl From<upstream::Model> for UpstreamInfo {
+    fn from(model: upstream::Model) -> Self {
+        Self {
+            id: model.id,
+            name: model.name,
+            protocol: model.protocol,
+            algorithm: model.algorithm,
+            sticky_session: model.sticky_session,
+            created_by: model.created_by,
+            created_at: model.created_at,
+            updated_at: model.updated_at,
+            upstream_targets: Vec::new(),
+        }
+    }
+}
+
+impl From<(upstream::Model, Option<Vec<upstream_target::Model>>)> for UpstreamInfo {
+    fn from(data: (upstream::Model, Option<Vec<upstream_target::Model>>)) -> Self {
+        let (upstream_model, upstream_target_models) = data;
+        if let Some(targets) = upstream_target_models {
+            UpstreamInfo::from((upstream_model, targets))
+        } else {
+            UpstreamInfo::from(upstream_model)
+        }
+    }
+}
+
+impl From<(upstream::Model, Vec<upstream_target::Model>)> for UpstreamInfo {
+    fn from(data: (upstream::Model, Vec<upstream_target::Model>)) -> Self {
+        let (upstream_model, upstream_target_models) = data;
+
+        Self {
+            id: upstream_model.id,
+            name: upstream_model.name,
+            protocol: upstream_model.protocol,
+            algorithm: upstream_model.algorithm,
+            sticky_session: upstream_model.sticky_session,
+            created_by: upstream_model.created_by,
+            created_at: upstream_model.created_at,
+            updated_at: upstream_model.updated_at,
+            upstream_targets: upstream_target_models
+                .into_iter()
+                .map(upstream_target_info::UpstreamTargetInfo::from)
+                .collect(),
+        }
+    }
+}
+
+impl From<UpstreamInfo> for (upstream::ActiveModel, Vec<upstream_target::ActiveModel>) {
+    fn from(val: UpstreamInfo) -> Self {
+        (
+            upstream::ActiveModel {
+                id: sea_orm::ActiveValue::Set(val.id),
+                name: sea_orm::ActiveValue::Set(val.name),
+                protocol: sea_orm::ActiveValue::Set(val.protocol),
+                algorithm: sea_orm::ActiveValue::Set(val.algorithm),
+                sticky_session: sea_orm::ActiveValue::Set(val.sticky_session),
+                created_by: sea_orm::ActiveValue::Set(val.created_by),
+                created_at: sea_orm::ActiveValue::Set(val.created_at),
+                updated_at: sea_orm::ActiveValue::Set(val.updated_at),
+            },
+            val.upstream_targets
+                .into_iter()
+                .map(|target| target.into())
+                .collect(),
+        )
+    }
+}
+
+impl UpdateUpstreamInfo {
+    pub fn apply_to_model(self, current_model: upstream::Model) -> upstream::ActiveModel {
+        upstream::ActiveModel {
+            id: Unchanged(current_model.id),
+            name: set_if_some!(self.name),
+            protocol: set_if_some!(self.protocol),
+            algorithm: set_if_some!(self.algorithm),
+            sticky_session: set_if_some!(self.sticky_session),
+            created_by: Unchanged(current_model.created_by),
+            created_at: Unchanged(current_model.created_at),
+            updated_at: Set(chrono::Utc::now()),
+        }
+    }
+}

apps/api/src/services/nginx/info/upstream_target.rs

@@ -0,0 +1,161 @@
+use chrono::{DateTime, Utc};
+
+use sea_orm::ActiveValue::{Set, Unchanged};
+use uuid::Uuid;
+
+use database::generated::entities::{upstream, upstream_target};
+
+use crate::{
+    services::nginx::{builder::NginxConfigProvider, traits::indentable::Indentable},
+    set_if_some,
+};
+
+#[derive(Clone)]
+pub struct UpstreamTargetInfo {
+    pub id: uuid::Uuid,
+    pub target_host: String,
+    pub target_port: i64,
+    pub weight: i64,
+    pub is_backup: bool,
+    pub enabled: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    //
+    pub upstream_id: uuid::Uuid,
+    pub upstream: Option<UpstreamBasicInfo>,
+}
+
+#[derive(Clone)]
+pub struct UpdateUpstreamTargetInfo {
+    pub target_host: Option<String>,
+    pub target_port: Option<i64>,
+    pub weight: Option<i64>,
+    pub is_backup: Option<bool>,
+    pub enabled: Option<bool>,
+}
+
+#[derive(Clone)]
+pub struct UpstreamBasicInfo {
+    pub id: uuid::Uuid,
+    pub name: String,
+    pub protocol: String,
+    //
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+pub struct UpstreamTargetCreateInfo {
+    pub target_host: String,
+    pub target_port: i64,
+    pub weight: i64,
+    pub is_backup: bool,
+    pub enabled: bool,
+    //
+    pub upstream_id: uuid::Uuid,
+}
+
+impl From<upstream_target::Model> for UpstreamTargetInfo {
+    fn from(model: upstream_target::Model) -> Self {
+        Self {
+            id: model.id,
+            target_host: model.target_host,
+            target_port: model.target_port,
+            weight: model.weight,
+            is_backup: model.is_backup,
+            enabled: model.enabled,
+            created_at: model.created_at,
+            updated_at: model.updated_at,
+            upstream_id: model.upstream_id,
+            upstream: None,
+        }
+    }
+}
+
+impl From<(upstream_target::Model, upstream::Model)> for UpstreamTargetInfo {
+    fn from(data: (upstream_target::Model, upstream::Model)) -> Self {
+        let (target_model, up_model) = data;
+        Self {
+            id: target_model.id,
+            target_host: target_model.target_host,
+            target_port: target_model.target_port,
+            weight: target_model.weight,
+            is_backup: target_model.is_backup,
+            enabled: target_model.enabled,
+            created_at: target_model.created_at,
+            updated_at: target_model.updated_at,
+            upstream_id: target_model.upstream_id,
+            upstream: Some(UpstreamBasicInfo {
+                id: up_model.id,
+                name: up_model.name,
+                protocol: up_model.protocol,
+                created_at: up_model.created_at,
+                updated_at: up_model.updated_at,
+            }),
+        }
+    }
+}
+
+impl From<UpstreamTargetInfo> for upstream_target::ActiveModel {
+    fn from(val: UpstreamTargetInfo) -> Self {
+        upstream_target::ActiveModel {
+            id: Set(val.id),
+            target_host: Set(val.target_host),
+            target_port: Set(val.target_port),
+            weight: Set(val.weight),
+            is_backup: Set(val.is_backup),
+            enabled: Set(val.enabled),
+            created_at: Set(val.created_at),
+            updated_at: Set(val.updated_at),
+            upstream_id: Set(val.upstream_id),
+        }
+    }
+}
+
+impl From<UpstreamTargetCreateInfo> for upstream_target::ActiveModel {
+    fn from(val: UpstreamTargetCreateInfo) -> Self {
+        upstream_target::ActiveModel {
+            id: Set(Uuid::new_v4()),
+            target_host: Set(val.target_host),
+            target_port: Set(val.target_port),
+            weight: Set(val.weight),
+            is_backup: Set(val.is_backup),
+            enabled: Set(val.enabled),
+            created_at: Set(chrono::Utc::now()),
+            updated_at: Set(chrono::Utc::now()),
+            upstream_id: Set(val.upstream_id),
+        }
+    }
+}
+
+impl NginxConfigProvider for UpstreamTargetInfo {
+    fn to_nginx_config(&self, indent: Option<usize>) -> String {
+        format!(
+            "server {}:{} weight={}{}{};",
+            self.target_host,
+            self.target_port,
+            self.weight,
+            if self.is_backup { " backup" } else { "" },
+            if !self.enabled { " down" } else { "" },
+        )
+        .indent(indent.unwrap_or(0))
+    }
+}
+
+impl UpdateUpstreamTargetInfo {
+    pub fn apply_to_model(
+        self,
+        current_model: upstream_target::Model,
+    ) -> upstream_target::ActiveModel {
+        upstream_target::ActiveModel {
+            id: Unchanged(current_model.id),
+            target_host: set_if_some!(self.target_host),
+            target_port: set_if_some!(self.target_port),
+            weight: set_if_some!(self.weight),
+            is_backup: set_if_some!(self.is_backup),
+            enabled: set_if_some!(self.enabled),
+            created_at: Unchanged(current_model.created_at),
+            updated_at: Set(chrono::Utc::now()),
+            upstream_id: Unchanged(current_model.upstream_id),
+        }
+    }
+}

apps/api/src/services/nginx/traits.rs

@@ -0,0 +1 @@
+pub mod indentable;

apps/api/src/services/nginx/traits/indentable.rs

@@ -0,0 +1,31 @@
+pub trait Indentable<T> {
+    fn indent(&self, spaces: T) -> String;
+}
+
+impl Indentable<usize> for &str {
+    fn indent(&self, spaces: usize) -> String {
+        let indent_str = " ".repeat(spaces);
+        self.lines()
+            .map(|line| format!("{}{}", indent_str, line))
+            .collect::<Vec<String>>()
+            .join("\n")
+    }
+}
+
+impl Indentable<Option<usize>> for String {
+    fn indent(&self, spaces: Option<usize>) -> String {
+        self.as_str().indent(spaces.unwrap_or(0))
+    }
+}
+
+impl Indentable<usize> for String {
+    fn indent(&self, spaces: usize) -> String {
+        self.as_str().indent(spaces)
+    }
+}
+
+impl Indentable<Option<usize>> for &str {
+    fn indent(&self, spaces: Option<usize>) -> String {
+        self.indent(spaces.unwrap_or(0))
+    }
+}

apps/api/src/services/nginx/upstream.rs

@@ -0,0 +1,881 @@
+use std::sync::Arc;
+
+use sea_orm::{
+    ActiveModelTrait, ColumnTrait, DatabaseConnection, DatabaseTransaction, EntityTrait, ExprTrait,
+    FromQueryResult, ModelTrait, QueryFilter, QuerySelect, QueryTrait, TransactionTrait,
+};
+
+use database::generated::entities::{upstream, upstream_target};
+
+use crate::{
+    errors::service_error::ServiceError,
+    helpers::database::PaginationFilter,
+    services::nginx::{
+        builder::NginxConfigBuilder,
+        info::{
+            upstream::{UpdateUpstreamInfo, UpstreamCreateInfo, UpstreamInfo},
+            upstream_target::{
+                UpdateUpstreamTargetInfo, UpstreamTargetCreateInfo, UpstreamTargetInfo,
+            },
+        },
+    },
+    with_conn,
+};
+
+#[async_trait::async_trait]
+pub trait UpstreamService: Send + Sync {
+    async fn create_upstream(
+        &self,
+        create_info: UpstreamCreateInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError>;
+    async fn get_total_upstreams(
+        &self,
+        options: Option<UpstreamTotalCountOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<u64, ServiceError>;
+    async fn get_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        options: Option<GetUpstreamOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError>;
+    async fn get_upstreams(
+        &self,
+        pagination: Option<PaginationFilter>,
+        options: Option<GetUpstreamOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<Vec<UpstreamInfo>, ServiceError>;
+    async fn update_upstream(
+        &self,
+        id: uuid::Uuid,
+        upstream: UpdateUpstreamInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError>;
+    async fn delete_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError>;
+    async fn create_upstream_target(
+        &self,
+        create_info: UpstreamTargetCreateInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError>;
+    async fn get_upstream_target(
+        &self,
+        target_id: uuid::Uuid,
+        options: Option<GetUpstreamTargetOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError>;
+    #[allow(dead_code)]
+    async fn get_upstream_targets_by_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<Vec<UpstreamTargetInfo>, ServiceError>;
+    async fn update_upstream_target(
+        &self,
+        id: uuid::Uuid,
+        target: UpdateUpstreamTargetInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError>;
+    async fn delete_upstream_target(
+        &self,
+        target_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError>;
+    async fn generate_config(
+        &self,
+        builder: &mut NginxConfigBuilder,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError>;
+}
+
+pub struct UpstreamServiceImpl {
+    connection: Arc<DatabaseConnection>,
+}
+
+#[derive(Default)]
+pub struct GetUpstreamOptions {
+    pub include_targets: bool,
+    pub filter_by_enabled: bool,
+}
+
+#[allow(dead_code)]
+pub struct UpstreamTotalCountOptions {}
+
+#[derive(Default)]
+pub struct GetUpstreamTargetOptions {
+    pub include_upstream: bool,
+}
+
+impl UpstreamServiceImpl {
+    pub fn new(connection: Arc<DatabaseConnection>) -> Self {
+        Self { connection }
+    }
+}
+
+#[async_trait::async_trait]
+impl UpstreamService for UpstreamServiceImpl {
+    async fn create_upstream(
+        &self,
+        create_info: UpstreamCreateInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError> {
+        let (upstream_model, upstream_target_models): (
+            upstream::ActiveModel,
+            Vec<upstream_target::ActiveModel>,
+        ) = create_info.into();
+
+        // If a transaction was provided use it, otherwise create and own one here.
+        let mut maybe_owned_tx: Option<DatabaseTransaction> = None;
+        let tx_ref: Option<&mut DatabaseTransaction> = if let Some(tx) = tx {
+            Some(tx)
+        } else {
+            maybe_owned_tx = Some(self.connection.begin().await?);
+            maybe_owned_tx.as_mut()
+        };
+
+        let r = with_conn!(&*self.connection, tx_ref, conn, {
+            let created_upstream = upstream_model.insert(*conn).await?;
+            let created_targets = upstream_target::Entity::insert_many(
+                upstream_target_models
+                    .into_iter()
+                    .map(|mut model| {
+                        model.upstream_id = sea_orm::ActiveValue::Set(created_upstream.id);
+                        model
+                    })
+                    .collect::<Vec<upstream_target::ActiveModel>>(),
+            )
+            .exec_with_returning(*conn)
+            .await?;
+            (created_upstream, created_targets)
+        });
+
+        // Commit only if we created the transaction here (we own it).
+        if let Some(t) = maybe_owned_tx.take() {
+            t.commit().await?;
+        }
+        Ok(r.into())
+    }
+
+    async fn get_total_upstreams(
+        &self,
+        _options: Option<UpstreamTotalCountOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<u64, ServiceError> {
+        #[derive(Debug, FromQueryResult)]
+        struct CountResult {
+            // The field name must match the column alias in the query
+            count: i64,
+        }
+        let count_info = with_conn!(&*self.connection, tx, conn, {
+            upstream::Entity::find()
+                .select_only()
+                .column_as(upstream::Column::Id, "count")
+                .into_model::<CountResult>()
+                .one(*conn)
+                .await?
+        });
+        Ok(count_info.map_or(0, |c| c.count) as u64)
+    }
+
+    async fn get_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        options: Option<GetUpstreamOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError> {
+        let concrete_options = options.unwrap_or_default();
+        let info: UpstreamInfo = if concrete_options.include_targets {
+            let (up_model, targets) = with_conn!(&*self.connection, tx, conn, {
+                let up = upstream::Entity::find_by_id(upstream_id)
+                    .one(*conn)
+                    .await?
+                    .ok_or(ServiceError::NotFound(format!(
+                        "Upstream with id {} not found",
+                        upstream_id
+                    )))?;
+                let targets = upstream_target::Entity::find()
+                    .filter(upstream_target::Column::UpstreamId.eq(upstream_id))
+                    .apply_if(Some(concrete_options.filter_by_enabled), |query, _v| {
+                        query.filter(upstream_target::Column::Enabled.eq(true))
+                    })
+                    .all(*conn)
+                    .await?;
+                (up, targets)
+            });
+            (up_model, targets).into()
+        } else {
+            with_conn!(&*self.connection, tx, conn, {
+                upstream::Entity::find_by_id(upstream_id)
+                    .one(*conn)
+                    .await?
+                    .ok_or(ServiceError::NotFound(format!(
+                        "Upstream with id {} not found",
+                        upstream_id
+                    )))?
+            })
+            .into()
+        };
+        Ok(info)
+    }
+
+    async fn get_upstreams(
+        &self,
+        pagination: Option<PaginationFilter>,
+        options: Option<GetUpstreamOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<Vec<UpstreamInfo>, ServiceError> {
+        let r = with_conn!(&*self.connection, tx, conn, {
+            let find_query = upstream::Entity::find();
+            let find_query = if let Some(pagination) = pagination {
+                let (offset, limit) = pagination.get_offset_limit();
+                find_query.offset(offset).limit(limit)
+            } else {
+                find_query
+            };
+            let find_query = match options {
+                Some(opts) => {
+                    if opts.include_targets && opts.filter_by_enabled {
+                        find_query.filter(
+                            upstream_target::Column::Enabled
+                                .eq(true)
+                                .or(upstream_target::Column::Id.is_null()),
+                        )
+                    } else {
+                        find_query
+                    }
+                }
+                _ => find_query,
+            };
+            find_query
+                .find_with_related(upstream_target::Entity)
+                .all(*conn)
+                .await?
+        });
+
+        Ok(r.into_iter().map(|m| m.into()).collect())
+    }
+
+    async fn update_upstream(
+        &self,
+        id: uuid::Uuid,
+        upstream: UpdateUpstreamInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamInfo, ServiceError> {
+        // If a transaction was provided use it, otherwise create and own one here.
+        let mut maybe_owned_tx: Option<DatabaseTransaction> = None;
+        let tx_ref: Option<&mut DatabaseTransaction> = if let Some(tx) = tx {
+            Some(tx)
+        } else {
+            maybe_owned_tx = Some(self.connection.begin().await?);
+            maybe_owned_tx.as_mut()
+        };
+
+        let current_model = with_conn!(&*self.connection, tx_ref, conn, {
+            upstream::Entity::find_by_id(id)
+                .one(*conn)
+                .await?
+                .ok_or(ServiceError::NotFound(format!(
+                    "Upstream with id {} not found",
+                    id
+                )))?
+        });
+        let upstream_active_model = upstream.clone().apply_to_model(current_model);
+
+        let r = with_conn!(&*self.connection, tx_ref, conn, {
+            let updated_upstream_model = upstream_active_model.update(*conn).await?;
+
+            // update upstream targets if any
+            if let Some(targets) = upstream.upstream_targets {
+                for (target_id, enabled) in targets.into_iter() {
+                    let target_model = upstream_target::Entity::find_by_id(target_id)
+                        .one(*conn)
+                        .await?
+                        .ok_or(ServiceError::NotFound(format!(
+                            "Upstream target with id {} not found",
+                            target_id
+                        )))?;
+                    let mut target_active_model: upstream_target::ActiveModel = target_model.into();
+                    target_active_model.enabled = sea_orm::ActiveValue::Set(enabled);
+
+                    target_active_model.update(*conn).await?;
+                    Ok::<(), ServiceError>(())?;
+                }
+            }
+
+            updated_upstream_model
+        });
+
+        // Commit
+        if let Some(t) = maybe_owned_tx.take() {
+            t.commit().await?;
+        }
+        Ok(r.into())
+    }
+
+    async fn delete_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        let model = with_conn!(&*self.connection, tx, conn, {
+            upstream::Entity::find_by_id(upstream_id)
+                .one(*conn)
+                .await?
+                .ok_or(ServiceError::NotFound(format!(
+                    "Upstream with id {} not found",
+                    upstream_id
+                )))?
+        });
+        with_conn!(&*self.connection, tx, conn, {
+            // delete all targets belonging to the upstream
+            upstream_target::Entity::delete_many()
+                .filter(upstream_target::Column::UpstreamId.eq(upstream_id))
+                .exec(*conn)
+                .await?;
+            model.delete(*conn).await?;
+            Ok(())
+        })
+    }
+
+    //
+    //
+    async fn create_upstream_target(
+        &self,
+        create_info: UpstreamTargetCreateInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError> {
+        let model: upstream_target::ActiveModel = create_info.into();
+        let r = with_conn!(&*self.connection, tx, conn, { model.insert(*conn).await? });
+        Ok(r.into())
+    }
+
+    async fn get_upstream_target(
+        &self,
+        target_id: uuid::Uuid,
+        options: Option<GetUpstreamTargetOptions>,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError> {
+        let concrete_options = options.unwrap_or_default();
+        let info: UpstreamTargetInfo = if concrete_options.include_upstream {
+            match with_conn!(&*self.connection, tx, conn, {
+                upstream_target::Entity::find_by_id(target_id)
+                    .find_also_related(upstream::Entity)
+                    .one(*conn)
+                    .await?
+            }) {
+                Some((target_model, Some(upstream_model))) => (target_model, upstream_model).into(),
+                Some((_target_model, None)) => {
+                    return Err(ServiceError::InternalError(format!(
+                        "Inconsistent data: Upstream target with id {} has no associated upstream",
+                        target_id
+                    )));
+                }
+                None => {
+                    return Err(ServiceError::NotFound(format!(
+                        "Upstream target with id {} not found",
+                        target_id
+                    )));
+                }
+            }
+        } else {
+            with_conn!(&*self.connection, tx, conn, {
+                upstream_target::Entity::find_by_id(target_id)
+                    .one(*conn)
+                    .await?
+                    .ok_or(ServiceError::NotFound(format!(
+                        "Upstream target with id {} not found",
+                        target_id
+                    )))?
+            })
+            .into()
+        };
+        Ok(info)
+    }
+
+    async fn get_upstream_targets_by_upstream(
+        &self,
+        upstream_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<Vec<UpstreamTargetInfo>, ServiceError> {
+        let r = with_conn!(&*self.connection, tx, conn, {
+            upstream_target::Entity::find()
+                .filter(upstream_target::Column::UpstreamId.eq(upstream_id))
+                .all(*conn)
+                .await?
+        });
+        Ok(r.into_iter().map(|m| m.into()).collect())
+    }
+
+    async fn update_upstream_target(
+        &self,
+        id: uuid::Uuid,
+        target: UpdateUpstreamTargetInfo,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<UpstreamTargetInfo, ServiceError> {
+        let current_model = with_conn!(&*self.connection, tx, conn, {
+            upstream_target::Entity::find_by_id(id)
+                .one(*conn)
+                .await?
+                .ok_or(ServiceError::NotFound(format!(
+                    "Upstream target with id {} not found",
+                    id
+                )))?
+        });
+        let active_model = target.apply_to_model(current_model);
+
+        let r = with_conn!(&*self.connection, tx, conn, {
+            active_model.update(*conn).await?
+        });
+        Ok(r.into())
+    }
+
+    async fn delete_upstream_target(
+        &self,
+        target_id: uuid::Uuid,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        let model = with_conn!(&*self.connection, tx, conn, {
+            upstream_target::Entity::find_by_id(target_id)
+                .one(*conn)
+                .await?
+                .ok_or(ServiceError::NotFound(format!(
+                    "Upstream target with id {} not found",
+                    target_id
+                )))?
+        });
+        with_conn!(&*self.connection, tx, conn, {
+            model.delete(*conn).await?;
+            Ok(())
+        })
+    }
+
+    async fn generate_config(
+        &self,
+        builder: &mut NginxConfigBuilder,
+        tx: Option<&mut DatabaseTransaction>,
+    ) -> Result<(), ServiceError> {
+        // get all upstreams and their targets
+        let upstreams = with_conn!(&*self.connection, tx, conn, {
+            upstream::Entity::find()
+                .find_with_related(upstream_target::Entity)
+                .all(*conn)
+                .await?
+        });
+        let upstreams_info = upstreams
+            .into_iter()
+            .map(|(up_model, target_models)| (up_model, target_models).into())
+            .collect::<Vec<UpstreamInfo>>();
+        builder.add_upstreams(upstreams_info);
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::Arc;
+
+    use sea_orm::MockExecResult;
+    use sea_orm::{DatabaseBackend, MockDatabase};
+
+    use database::generated::entities::{upstream, upstream_target};
+
+    #[tokio::test]
+    async fn create_upstream_returns_info() {
+        let up_model = upstream::Model {
+            id: uuid::Uuid::new_v4(),
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![up_model.clone()]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let create_info = crate::services::nginx::info::upstream::UpstreamCreateInfo {
+            name: "test_upstream".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "round_robin".to_string(),
+            sticky_session: false,
+            created_by: None,
+            upstream_targets: Vec::new(),
+        };
+
+        let res = svc.create_upstream(create_info, None).await;
+        assert!(res.is_ok());
+        let info = res.expect("Failed to create upstream");
+        assert_eq!(info.name, "test_upstream");
+    }
+
+    #[tokio::test]
+    async fn get_upstream_with_targets_returns_targets() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let up_model = upstream::Model {
+            id: up_id,
+            name: "with_targets".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "least_conn".to_string(),
+            sticky_session: true,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let target_model = upstream_target::Model {
+            id: uuid::Uuid::new_v4(),
+            upstream_id: up_id,
+            target_host: "127.0.0.1".to_string(),
+            target_port: 8080,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            // find_by_id -> returns upstream model
+            .append_query_results(vec![vec![up_model.clone()]])
+            // find targets -> returns the target(s)
+            .append_query_results(vec![vec![target_model.clone()]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc
+            .get_upstream(
+                up_id,
+                Some(GetUpstreamOptions {
+                    include_targets: true,
+                    filter_by_enabled: false,
+                }),
+                None,
+            )
+            .await;
+
+        assert!(res.is_ok());
+        let info = res.expect("Failed to get upstream with targets");
+        assert_eq!(info.id, up_id);
+        assert_eq!(info.upstream_targets.len(), 1);
+        assert_eq!(info.upstream_targets[0].target_host, "127.0.0.1");
+    }
+
+    #[tokio::test]
+    async fn get_upstream_not_found_returns_not_found() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc.get_upstream(uuid::Uuid::new_v4(), None, None).await;
+
+        assert!(matches!(res, Err(ServiceError::NotFound(_))));
+    }
+
+    #[tokio::test]
+    async fn get_upstreams_returns_list() {
+        let u1 = upstream::Model {
+            id: uuid::Uuid::new_v4(),
+            name: "u1".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+        let u2 = upstream::Model {
+            id: uuid::Uuid::new_v4(),
+            name: "u2".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![
+                (u1.clone(), None::<upstream_target::Model>),
+                (u2.clone(), None::<upstream_target::Model>),
+            ]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc.get_upstreams(None, None, None).await;
+        assert!(res.is_ok());
+        let list = res.expect("Failed to get upstreams");
+        assert_eq!(list.len(), 2);
+    }
+
+    #[tokio::test]
+    async fn get_upstream_targets_by_upstream_returns_targets() {
+        let up_id = uuid::Uuid::new_v4();
+
+        let t = upstream_target::Model {
+            id: uuid::Uuid::new_v4(),
+            upstream_id: up_id,
+            target_host: "10.0.0.1".to_string(),
+            target_port: 80,
+            weight: 10,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![t.clone()]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc.get_upstream_targets_by_upstream(up_id, None).await;
+        assert!(res.is_ok());
+        let targets = res.expect("Failed to get upstream targets");
+        assert_eq!(targets.len(), 1);
+        assert_eq!(targets[0].target_host, "10.0.0.1");
+    }
+
+    #[tokio::test]
+    async fn update_upstream_success() {
+        let id = uuid::Uuid::new_v4();
+        let existing = upstream::Model {
+            id,
+            name: "old".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+        let updated = upstream::Model {
+            id,
+            name: "new".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: existing.created_at,
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]]) // find_by_id
+            .append_query_results(vec![vec![updated.clone()]]) // update result
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let update_info = crate::services::nginx::info::upstream::UpdateUpstreamInfo {
+            name: None,
+            protocol: None,
+            algorithm: None,
+            sticky_session: None,
+            upstream_targets: None,
+        };
+        let res = svc.update_upstream(id, update_info, None).await;
+        assert!(res.is_ok());
+        let got = res.expect("Failed to update upstream");
+        assert_eq!(got.name, "new");
+    }
+
+    #[tokio::test]
+    async fn update_upstream_not_found() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc
+            .update_upstream(
+                uuid::Uuid::new_v4(),
+                crate::services::nginx::info::upstream::UpdateUpstreamInfo {
+                    name: None,
+                    protocol: None,
+                    algorithm: None,
+                    sticky_session: None,
+
+                    upstream_targets: None,
+                },
+                None,
+            )
+            .await;
+
+        assert!(matches!(res, Err(ServiceError::NotFound(_))));
+    }
+
+    #[tokio::test]
+    async fn delete_upstream_success() {
+        let id = uuid::Uuid::new_v4();
+        let existing = upstream::Model {
+            id,
+            name: "todelete".to_string(),
+            protocol: "http".to_string(),
+            algorithm: "rr".to_string(),
+            sticky_session: false,
+            created_by: None,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]])
+            .append_exec_results(vec![
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+                MockExecResult {
+                    rows_affected: 1,
+                    last_insert_id: 0,
+                },
+            ])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc.delete_upstream(id, None).await;
+        assert!(res.is_ok());
+    }
+
+    #[tokio::test]
+    async fn delete_upstream_not_found() {
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![Vec::<sea_orm::MockRow>::new()])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let res = svc.delete_upstream(uuid::Uuid::new_v4(), None).await;
+        assert!(matches!(res, Err(ServiceError::NotFound(_))));
+    }
+
+    #[tokio::test]
+    async fn create_upstream_target_success() {
+        let id = uuid::Uuid::new_v4();
+        let upstream_id = uuid::Uuid::new_v4();
+        let created = upstream_target::Model {
+            id,
+            upstream_id,
+            target_host: "1.2.3.4".to_string(),
+            target_port: 8080,
+            weight: 5,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![created.clone()]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let create_info = crate::services::nginx::info::upstream_target::UpstreamTargetCreateInfo {
+            target_host: "1.2.3.4".to_string(),
+            target_port: 8080,
+            weight: 5,
+            is_backup: false,
+            enabled: true,
+            upstream_id,
+        };
+
+        let res = svc.create_upstream_target(create_info, None).await;
+        assert!(res.is_ok());
+        let t = res.expect("Failed to create target");
+        assert_eq!(t.target_host, "1.2.3.4");
+    }
+
+    #[tokio::test]
+    async fn update_upstream_target_success() {
+        let id = uuid::Uuid::new_v4();
+        let existing = upstream_target::Model {
+            id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "old".to_string(),
+            target_port: 80,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+        let updated = upstream_target::Model {
+            id,
+            upstream_id: existing.upstream_id,
+            target_host: "new".to_string(),
+            target_port: 80,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: existing.created_at,
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]])
+            .append_query_results(vec![vec![updated.clone()]])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+
+        let update_info = crate::services::nginx::info::upstream_target::UpdateUpstreamTargetInfo {
+            target_host: None,
+            target_port: None,
+            weight: None,
+            is_backup: None,
+            enabled: None,
+        };
+        let res = svc.update_upstream_target(id, update_info, None).await;
+        assert!(res.is_ok());
+        let got = res.expect("Failed to update target");
+        assert_eq!(got.target_host, "new");
+    }
+
+    #[tokio::test]
+    async fn delete_upstream_target_success() {
+        let id = uuid::Uuid::new_v4();
+        let existing = upstream_target::Model {
+            id,
+            upstream_id: uuid::Uuid::new_v4(),
+            target_host: "del".to_string(),
+            target_port: 80,
+            weight: 1,
+            is_backup: false,
+            enabled: true,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+
+        let db = MockDatabase::new(DatabaseBackend::Sqlite)
+            .append_query_results(vec![vec![existing.clone()]])
+            .append_exec_results(vec![MockExecResult {
+                rows_affected: 1,
+                last_insert_id: 0,
+            }])
+            .into_connection();
+
+        let svc = UpstreamServiceImpl::new(Arc::new(db));
+        let res = svc.delete_upstream_target(id, None).await;
+        assert!(res.is_ok());
+    }
+}

apps/api/src/services/server_state.rs

@@ -0,0 +1,36 @@
+use std::sync::Arc;
+
+use sea_orm::{DatabaseConnection, prelude::*};
+
+use crate::errors::service_error::ServiceError;
+
+#[async_trait::async_trait]
+pub trait ServerStateStore: Send + Sync {
+    async fn is_server_initialized(&self) -> Result<bool, ServiceError>;
+}
+
+pub struct ServerStateService {
+    connection: Arc<DatabaseConnection>,
+}
+
+impl ServerStateService {
+    pub fn new(connection: Arc<DatabaseConnection>) -> Self {
+        Self { connection }
+    }
+}
+
+#[async_trait::async_trait]
+impl ServerStateStore for ServerStateService {
+    async fn is_server_initialized(&self) -> Result<bool, ServiceError> {
+        // For example, check if any admin user exists to determine if the server is initialized
+        let admin_exists = database::generated::entities::user::Entity::find()
+            .filter(database::generated::entities::user::Column::IsAdmin.eq(true))
+            .filter(database::generated::entities::user::Column::IsActive.eq(true))
+            .one(&*self.connection)
+            .await
+            .map_err(ServiceError::from)?
+            .is_some();
+
+        Ok(admin_exists)
+    }
+}

apps/api/src/services/settings.rs

@@ -7,18 +7,15 @@ use sea_orm::{
     IntoActiveModel, QueryFilter,
 };
 
-use crate::errors::service_error::{IntoServiceError, ServiceError};
+use crate::errors::service_error::ServiceError;
 
 #[async_trait::async_trait]
 pub trait SettingsStore: Send + Sync {
-    #[allow(dead_code)] // TODO: remove when used
     async fn get_setting(&self, key: &str) -> Result<String, ServiceError>;
-    #[allow(dead_code)] // TODO: remove when used
     async fn set_setting(&self, key: &str, value: String) -> Result<(), ServiceError>;
 }
 
 pub struct SettingsService {
-    #[allow(dead_code)] // TODO: remove when used
     connection: Arc<DatabaseConnection>,
 }
 
@@ -37,11 +34,11 @@ impl SettingsStore for SettingsService {
             .await;
 
         match setting {
-            Err(err) => Err(err.into_service_error()),
-            Ok(None) => Err(
-                DbErr::RecordNotFound(format!("Setting with key '{}' not found", key))
-                    .into_service_error(),
-            ),
+            Err(err) => Err(ServiceError::from(err)),
+            Ok(None) => Err(ServiceError::from(DbErr::RecordNotFound(format!(
+                "Setting with key '{}' not found",
+                key
+            )))),
             Ok(Some(record)) => Ok(record.value),
         }
     }
@@ -62,7 +59,7 @@ impl SettingsStore for SettingsService {
             new_record
                 .insert(&*self.connection)
                 .await
-                .map_err(|err| err.into_service_error())
+                .map_err(ServiceError::from)
         };
 
         match existing {
@@ -71,19 +68,20 @@ impl SettingsStore for SettingsService {
                     handle_not_found(key.to_string(), value).await?;
                 }
                 _ => {
-                    return Err(Box::new(err));
+                    return Err(ServiceError::from(err));
                 }
             },
             Ok(None) => {
                 handle_not_found(key.to_string(), value).await?;
             }
-            Ok(Some(mut record)) => {
-                record.value = value;
-                record
-                    .into_active_model()
+            Ok(Some(record)) => {
+                let mut record_active_model = record.into_active_model();
+                record_active_model.value = ActiveValue::Set(value);
+                record_active_model.updated_at = ActiveValue::Set(chrono::Utc::now());
+                record_active_model
                     .update(&*self.connection)
                     .await
-                    .map_err(|err| err.into_service_error())?;
+                    .map_err(ServiceError::from)?;
             }
         }
 

apps/api/src/tasks/startup.rs

@@ -1,25 +1,34 @@
-use migration::migrate_database;
-use tracing::{debug, info};
+mod db_migrate;
+mod init_admin;
+
+use std::sync::Arc;
+
+use sea_orm::ConnectOptions;
+use tracing::info;
 
 use crate::configs::ProgramSettings;
+use database::get_connection;
 
 pub async fn run_startup_tasks(config: &ProgramSettings) -> Result<(), Box<dyn std::error::Error>> {
     // Here you can add any startup tasks you want to run when the application starts.
     info!("Running startup tasks...");
+
+    let db_options = |options: &mut ConnectOptions| {
+        options.max_connections(config.database.max_connections);
+    };
+
+    let db_connection = Arc::new(
+        get_connection(&config.database.url, Some(db_options))
+            .await
+            .map_err(|err| format!("Failed to establish database connection: {}", err))?,
+    );
+
     if config.database.migrate_on_startup {
-        run_database_migrations(&config.database.url).await?;
+        db_migrate::run_database_migrations(&config.database.url).await?;
     } else {
         info!("Database migration on startup is disabled. Skipping migration.");
     }
+    init_admin::init_admin(config, db_connection.clone()).await?;
 
     Ok(())
 }
-
-async fn run_database_migrations(db_url: &str) -> Result<(), Box<dyn std::error::Error>> {
-    // Logic to run database migrations
-    info!("Running database migrations...");
-    debug!("Database URL: {}", db_url);
-    migrate_database(db_url).await.map_err(Box::new)?;
-    info!("Database migrations completed.");
-    Ok(())
-}

apps/api/src/tasks/startup/db_migrate.rs

@@ -0,0 +1,11 @@
+use migration::migrate_database;
+use tracing::{debug, info};
+
+pub async fn run_database_migrations(db_url: &str) -> Result<(), Box<dyn std::error::Error>> {
+    // Logic to run database migrations
+    info!("Running database migrations...");
+    debug!("Database URL: {}", db_url);
+    migrate_database(db_url).await.map_err(Box::new)?;
+    info!("Database migrations completed.");
+    Ok(())
+}

apps/api/src/tasks/startup/init_admin.rs

@@ -0,0 +1,116 @@
+use std::sync::Arc;
+
+use argon2::password_hash::{SaltString, rand_core::OsRng};
+use database::generated::entities::user;
+use sea_orm::{ColumnTrait, DatabaseConnection, EntityTrait, QueryFilter, TransactionTrait};
+use tracing::{debug, info, warn};
+
+use crate::configs::ProgramSettings;
+use crate::helpers::constants::ADMIN_INIT_SECRET_KEY;
+use crate::services::{
+    auth::{
+        authentication::strategies::password::PasswordStrategy,
+        user::{NewUser, UserService, UserServiceImpl},
+    },
+    settings::{SettingsService, SettingsStore},
+};
+
+pub async fn init_admin(
+    config: &ProgramSettings,
+    db: Arc<DatabaseConnection>,
+) -> Result<(), Box<dyn std::error::Error>> {
+    // if admin user already exists, skip
+    let admin_exists = user::Entity::find()
+        .filter(user::Column::IsAdmin.eq(true))
+        .filter(user::Column::IsActive.eq(true))
+        .one(db.as_ref())
+        .await
+        .map_err(|err| format!("Failed to query for existing admin user: {}", err))?
+        .is_some();
+
+    if admin_exists {
+        debug!("Admin user already exists. Skipping admin initialization.");
+        return Ok(());
+    }
+
+    // if config contains admin init settings, run admin init
+    if let (Some(username), Some(password)) = (
+        &config.auth.default_admin_username,
+        &config.auth.default_admin_password,
+    ) {
+        let r = _init_admin(username, password, db.clone()).await;
+        if let Err(e) = r {
+            warn!("Failed to initialize admin user: {}", e);
+            info!("Defaulting to manual creation from dashboard.");
+        } else {
+            return Ok(());
+        }
+    }
+    // else generate a random secret to be used when initializing admin from dashboard
+    let secret = generate_admin_init_secret(db.clone()).await?;
+    info!(
+        "Admin initialization secret generated. Use this secret to initialize the admin user from the dashboard: {}. This secret will only be shown once and is only valid until the admin user is created or the application is restarted.",
+        secret
+    );
+    Ok(())
+}
+
+async fn generate_admin_init_secret(
+    db: Arc<DatabaseConnection>,
+) -> Result<String, Box<dyn std::error::Error>> {
+    let secret = SaltString::generate(&mut OsRng).as_str().to_owned();
+
+    // Store the secret in a settings table
+    let setting = SettingsService::new(db.clone());
+    setting
+        .set_setting(ADMIN_INIT_SECRET_KEY, secret.clone())
+        .await
+        .map_err(|err| format!("Failed to store admin init secret: {}", err))?;
+
+    Ok(secret)
+}
+
+async fn _init_admin(
+    username: &str,
+    password: &str,
+    db: Arc<DatabaseConnection>,
+) -> Result<(), Box<dyn std::error::Error>> {
+    info!("Initializing admin user...");
+    // Check if an admin user already exists
+    let admin_exists = user::Entity::find()
+        .filter(user::Column::IsAdmin.eq(true))
+        .one(db.as_ref())
+        .await?
+        .is_some();
+
+    if admin_exists {
+        debug!("Admin user already exists. Skipping initialization.");
+        return Ok(());
+    }
+    info!("No admin user found. Creating default admin user...");
+
+    let user_service = UserServiceImpl::new(db.clone());
+    let password_strategy = PasswordStrategy::new(db.clone());
+
+    let user = NewUser {
+        username: username.to_string(),
+        is_admin: true,
+    };
+
+    let mut tx = db.begin().await?;
+    // create user
+    let user = user_service.create_user(user, Some(&mut tx)).await?;
+    // create temporary password
+    password_strategy
+        .create_identity(user.id, password, Some(&mut tx))
+        .await?;
+    //
+    tx.commit().await?;
+
+    info!(
+        "Default admin user created successfully, username: {}",
+        username
+    );
+
+    Ok(())
+}

apps/cli/Cargo.toml

@@ -8,7 +8,7 @@ async-trait = "0.1.89"
 container-simulate = { path = "../container" }
 migration = {path = "../../public/migration"}
 shared = {path = "../../public/shared"}
-testcontainers = "0.24.0"
+testcontainers = "0.26.0"
 tokio = { version = "1.47.0", features = ["full"] }
 url = "2.5.7"
 clap = { version = "4.5.48", features = ["derive", "env"] }