shutdown-order

Shutdown order

shutdown-order (top-level) controls the sequence in which services are stopped during graceful shutdown.

Config

# Graceful shutdown ordering. With reverse-dep (the default), dependents
# stop before the dependencies they rely on.
shutdown-order: reverse-dep
processes:
  - name: db
    command: /bin/sh
    args: ["-c", "trap 'echo db >> STOPLOG; exit 0' TERM; while true; do sleep 0.2; done"]
    on-failure: shutdown
  - name: app
    command: /bin/sh
    args: ["-c", "trap 'echo app >> STOPLOG; exit 0' TERM; while true; do sleep 0.2; done"]
    after: [db]
    on-failure: shutdown

The three strategies:

• reverse-dep (default) — stop dependents first, then their dependencies. Here app stops before db.
• dep — stop dependencies first, then dependents. db would stop before app.
• simultaneous — signal all services at once.

Expected behavior

• db starts, then app (which depends on it).
• On SIGTERM with reverse-dep, app receives SIGTERM and exits before db is signaled.
• gopherd exits 0 once all services have stopped.

Test

Each service traps SIGTERM and appends its name to a shared log file before exiting. The test replaces the STOPLOG token with a temp-dir path, starts the daemon, waits for both services to be running, then sends SIGTERM.

Because reverse-dep stops sequentially — signaling a service and waiting for it to exit before moving to the next — the log order is deterministic. The test asserts that the log contains exactly ["app", "db"], proving that the dependent stopped before its dependency.

go test ./documentation/shutdown-order/ -v