handle signals golang

main.go

package main

import (
	"fmt"
	"os"
	"os/signal"
	"syscall"
	"time"
)

func main() {

	var returnCode = make(chan int)
	var finishUP = make(chan struct{})
	var done = make(chan struct{})
	
	var gracefulStop = make(chan os.Signal)
	
	signal.Notify(gracefulStop, syscall.SIGTERM)
	signal.Notify(gracefulStop, syscall.SIGINT)
	
	go func() {
		// wait for our os signal to stop the app
		// on the graceful stop channel
		sig := <-gracefulStop
		fmt.Printf("caught sig: %+v", sig)
		
		// send message on "finish up" channel to tell the app to
		// gracefully shutdown
		finishUP<-struct{}{}
		
		// wait for word back if we finished or not
		select {
		case <-time.After(30*time.Second):
			// timeout after 30 seconds waiting for app to finish
			returnCode<-1
		case <-done:
			// if we got a message on done, we finished, so end app
			returnCode<-0
		}
	}()
	
	fmt.Println("waiting for finish")
	// wait for finishUP channel write to close the app down
	<-finishUP
	fmt.Println("stopping things, might take 2 seconds")
	time.Sleep(2*time.Second)
	// write to the done channel to signal we are done.
	done <-struct{}{}
	os.Exit(<-returnCode)
}