Webhooks

Run commands on service lifecycle events.

Events

Stage	When	Outcomes
on_start	Service spawn	success, error
on_stop	Service exit	success, error
on_restart	Auto-restart after crash	success, error

• Manual stops = success
• Crashes = error
• Only auto-restarts trigger on_restart

Configuration

services:
  postgres:
    command: "postgres -D /var/lib/postgres"
    hooks:
      on_start:
        success:
          command: "curl --request POST https://api.example.com/start"
          timeout: "10s"
        error:
          command: "curl --request POST https://api.example.com/failed"
      on_stop:
        error:
          command: "curl --request POST https://api.example.com/crashed"

Hooks inherit service environment variables.

Execution

• Run via sh -c
• Fire-and-forget (no retries)
• Timeout kills with SIGKILL
• Failures logged but don't affect service

Behavior

Scenario	Hooks
Start success	on_start.success
Start failure	on_start.error
Manual stop	on_stop.success
Crash	on_stop.error → restart
Restart after crash	on_stop.error, on_start.success, on_restart.success

Tips

• Keep commands short
• Use env vars for secrets
• Make endpoints idempotent