README.md

Golang App Shutdown Hooks

This package provides convenient interface for working with os.Signal.

Multiple hooks can be applied, they will be called simultaneously on app shutdown.

Example

package main

import (
	"log"
	"time"

	"github.com/ztrue/shutdown"
)

func main() {
	shutdown.Add(func() {
		// Write log.
		// Stop writing files.
		// Close connections.
		// Etc.
		log.Println("Stopping...")
		log.Println("3")
		time.Sleep(time.Second)
		log.Println("2")
		time.Sleep(time.Second)
		log.Println("1")
		time.Sleep(time.Second)
		log.Println("0, stopped")
	})

	// App emulation.
	go func() {
		log.Println("App running, press CTRL + C to stop")
		select {}
	}()

	shutdown.Listen()
}

Find more executable examples in examples dir.

How to Use

Import

import "github.com/ztrue/shutdown"

Add Shutdown Hook

shutdown.Add(func() {
	log.Println("Stopping")
})

Remove Hook

key := shutdown.Add(func() {
	log.Println("Stopping")
})

shutdown.Remove(key)

Hook With Custom Key

shutdown.AddWithKey("mykey", func() {
	log.Println("Stopping")
})

shutdown.Remove("mykey")

Hook With Signal Parameter

shutdown.AddWithParam(func(os.Signal) {
	log.Println("Stopping because of", os.Signal)
})

Listen for Specific Signals

shutdown.Listen(syscall.SIGINT, syscall.SIGTERM)

Reload

Reload service on SIGHUP

	shutdown.AddWithParam(func(sig os.Signal) {
		if sig == syscall.SIGHUP {
			log.Println( "Reload conf...")
			reloadConf()
			// listen again signals to avoid shutdown
			shutdown.Listen(syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
		} else { // SIGINT, SIGTERM
			log.Println("Stopping...")
		}
	})
	shutdown.Listen(syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)