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.