go_1.8_http_graceful_shutdown

http_graceful_shutdown.go

package main

import (
	"context"
	"fmt"
	"html"
	"log"
	"net/http"
	"os"
	"os/signal"
)

func main() {
	// subscribe to SIGINT signals
	quit := make(chan os.Signal)
	signal.Notify(quit, os.Interrupt,syscall.SIGINT)

	srv := &http.Server{Addr: ":8080", Handler: http.DefaultServeMux}
	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
	})

	go func() {
		err := srv.ListenAndServe()
		if err != http.ErrServerClosed {
             		log.Errf("listen: %s\n", err)
         	}
		quit <- syscall.SIGINT
	}
	
	<-quit

	// When Shutdown is called, Serve, ListenAndServe, 
	// and ListenAndServeTLS immediately return ErrServerClosed. 
	// Make sure the program doesn't exit and waits instead for Shutdown to return.
	log.Println("Shutting down server...")
	if err := srv.Shutdown(context.Background()); err != nil {
		log.Errf("could not shutdown: %v", err)
	}
}

d := time.Now().Add(5 * time.Second) 
ctx, cancel := context.WithDeadline(context.Background(), d)

defer cancel()

   if err := srv.Shutdown(ctx)