hooks

Lifecycle Hooks Example

This example demonstrates how to use lifecycle hooks (WithBeforeShutdown and WithAfterShutdown) to execute custom logic during graceful shutdown.

Usage

go run main.go

Then send a request:

curl http://localhost:8080/

To see the hooks in action, stop the server with Ctrl+C (SIGTERM).

Expected Output

When you stop the server, you should see output like:

Shutdown signal received, starting graceful shutdown...
HOOK: Before shutdown - Notifying load balancer...
HOOK: Load balancer notified
HOOK: Before shutdown - Stopping background workers...
HOOK: Background workers stopped
HOOK: After shutdown - Closing database connections...
HOOK: Database connections closed
HOOK: After shutdown - Flushing metrics...
HOOK: Metrics flushed
Server stopped gracefully

Hook Execution Order

1. BeforeShutdown hooks - Execute in registration order before server shutdown begins

   • Notify load balancer to stop sending traffic
   • Stop background workers

2. Server Shutdown - All HTTP servers shut down gracefully

3. AfterShutdown hooks - Execute in registration order after servers have stopped

   • Close database connections
   • Flush metrics to external service

Use Cases

• BeforeShutdown: Deregister from service discovery, notify load balancers, stop accepting new work
• AfterShutdown: Close database connections, flush buffers, cleanup resources, send final metrics