Graceful restart or stop

Do you want to graceful restart or stop your web server? There are some ways this can be done.

We can use fvbock/endless to replace the default ListenAndServe. Refer issue #296 for more details.

router := gin.Default()
router.GET("/", handler)
// [...]
endless.ListenAndServe(":4242", router)

An alternative to endless:

  • manners: A polite Go HTTP server that shuts down gracefully.
  • graceful: Graceful is a Go package enabling graceful shutdown of an http.Handler server.
  • grace: Graceful restart & zero downtime deploy for Go servers.

If you are using Go 1.8, you may not need to use this library! Consider using http.Server’s built-in Shutdown() method for graceful shutdowns. See the full graceful-shutdown example with gin.

// +build go1.8

package main

import (
	"context"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"github.com/gin-gonic/gin"
)

func main() {
	router := gin.Default()
	router.GET("/", func(c *gin.Context) {
		time.Sleep(5 * time.Second)
		c.String(http.StatusOK, "Welcome Gin Server")
	})

	srv := &http.Server{
		Addr:    ":8080",
		Handler: router,
	}

	go func() {
		// service connections
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("listen: %s\n", err)
		}
	}()

	// Wait for interrupt signal to gracefully shutdown the server with
	// a timeout of 5 seconds.
	quit := make(chan os.Signal)
	// kill (no param) default send syscanll.SIGTERM
	// kill -2 is syscall.SIGINT
	// kill -9 is syscall. SIGKILL but can"t be catch, so don't need add it
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("Shutdown Server ...")

	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := srv.Shutdown(ctx); err != nil {
		log.Fatal("Server Shutdown:", err)
	}
	// catching ctx.Done(). timeout of 5 seconds.
	select {
	case <-ctx.Done():
		log.Println("timeout of 5 seconds.")
	}
	log.Println("Server exiting")
}
Last modified February 24, 2020: add comment (#106) (fcbe912)