Golang mux webserver - Testing graceful shutdown behavior

gistfile1.txt

package main

import (
	"context"
	"flag"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"time"

	"github.com/gorilla/mux"
)

func QuickEndpoint(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("Endpoint hit!\n"))
}

func LongRunningTaskForegroundEndpoint(w http.ResponseWriter, r *http.Request) {
	for i := 0; i < 10; i++ {
		time.Sleep(1 * time.Second)
		fmt.Print("=")
	}
	fmt.Print(".")
	w.Write([]byte("Long Running Task Foreground Endpoint 1 hit!\n"))
}

func LongRunningTaskForegroundEndpoint2(w http.ResponseWriter, r *http.Request) {
	fmt.Println("10 segundos de pausa")
	time.Sleep(10 * time.Second)
	w.Write([]byte("Long Running Task Foreground Endpoint 2 hit!\n"))
}

func LongRunningTaskBackgroundEndpoint(w http.ResponseWriter, r *http.Request) {
	go func() {
		for i := 0; i < 10; i++ {
			time.Sleep(1 * time.Second)
			fmt.Print("=")
		}
		fmt.Print(".")
	}()
	w.Write([]byte("Long Running Task Background Endpoint hit!\n"))
}

func main() {
	var wait time.Duration
	flag.DurationVar(&wait, "graceful-timeout", time.Second*15, "the duration for which the server gracefully wait for existing connections to finish - e.g. 15s or 1m")
	flag.Parse()

	r := mux.NewRouter()
	// Add your routes as needed

	r.HandleFunc("/quick", QuickEndpoint)
	r.HandleFunc("/long-fore", LongRunningTaskForegroundEndpoint)
	r.HandleFunc("/long-fore-2", LongRunningTaskForegroundEndpoint2)
	r.HandleFunc("/long-back", LongRunningTaskBackgroundEndpoint)
	srv := &http.Server{
		Addr: "0.0.0.0:7070",
		// Good practice to set timeouts to avoid Slowloris attacks.
		WriteTimeout: time.Second * 15,
		ReadTimeout:  time.Second * 15,
		IdleTimeout:  time.Second * 60,
		Handler:      r, // Pass our instance of gorilla/mux in.
	}

	// Run our server in a goroutine so that it doesn't block.
	go func() {
		if err := srv.ListenAndServe(); err != nil {
			log.Println(err)
		}
	}()

	c := make(chan os.Signal, 1)
	// We'll accept graceful shutdowns when quit via SIGINT (Ctrl+C)
	// SIGKILL, SIGQUIT or SIGTERM (Ctrl+/) will not be caught.
	signal.Notify(c, os.Interrupt)

	// Block until we receive our signal.
	<-c

	// Create a deadline to wait for.
	ctx, cancel := context.WithTimeout(context.Background(), wait)
	defer cancel()
	// Doesn't block if no connections, but will otherwise wait
	// until the timeout deadline.
	srv.Shutdown(ctx)
	// Optionally, you could run srv.Shutdown in a goroutine and block on
	// <-ctx.Done() if your application should wait for other services
	// to finalize based on context cancellation.
	log.Println("shutting down")
	os.Exit(0)
}