init-stop-signal

init-stop-signal

The top-level init-stop-signal list defines which signals trigger gopherd's own graceful shutdown (stop all services, then exit). Setting it replaces the default [SIGTERM, SIGINT] entirely.

Config

init-stop-signal: [SIGUSR2]
processes:
  - name: app
    command: /usr/local/bin/app
    args: ["300"]
    on-failure: shutdown

• init-stop-signal: [SIGUSR2] — SIGUSR2 is now the only graceful-shutdown trigger. SIGTERM and SIGINT are no longer in the set.
• SIGKILL and SIGSTOP are rejected at load (they cannot be caught).

Expected behavior

• SIGUSR2 (which gopherd normally ignores) now triggers graceful shutdown: services are stopped cleanly and gopherd exits 0.

A caveat on the dropped defaults

Because the override removes SIGTERM/SIGINT from the set, gopherd no longer installs a handler for them. Inside gopherd's own process they fall back to the OS default disposition (terminate), so SIGTERM will still kill the process — but abruptly, not via the graceful shutdown path (it does not stop services cleanly first). In other words, the override changes which signal gives a clean shutdown; it does not make gopherd immune to a default-terminate signal. If you want SIGTERM to do nothing at all, do not rely on omitting it here.

Test

The test substitutes /usr/bin/sleep for the placeholder binary, asserts status app is running, sends SIGUSR2, and asserts gopherd exits 0 within the timeout — proving SIGUSR2 (normally a no-op) now drives graceful shutdown. Verified stable across repeated runs.

The SIGTERM caveat above is not asserted as a unit test because the abrupt default-terminate behavior depends on process disposition rather than gopherd logic; it is described in prose instead.

go test ./documentation/init-stop-signal/ -v