update readme graceful shutdown example

README.md

@@ -1831,31 +1831,38 @@ func main() {
 		Handler: router,
 	}
 
-	// Initializing the server in a goroutine so that
-	// it won't block the graceful shutdown handling below
-	go func() {
-		if err := srv.ListenAndServe(); err != nil && errors.Is(err, http.ErrServerClosed) {
-			log.Printf("listen: %s\n", err)
-		}
-	}()
+	// Receive another goroutine listen error
+	serverError := make(chan error, 1)
 
 	// Wait for interrupt signal to gracefully shutdown the server with
 	// a timeout of 5 seconds.
-	quit := make(chan os.Signal)
+	quit := make(chan os.Signal, 1)
+
+	// Initializing the server in a goroutine so that
+	// it won't block the graceful shutdown handling below
+	go func() {
+		serverError <- srv.ListenAndServe()
+	}()
+
 	// kill (no param) default send syscall.SIGTERM
 	// kill -2 is syscall.SIGINT
 	// kill -9 is syscall.SIGKILL but can't be caught, so don't need to add it
 	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
-	<-quit
-	log.Println("Shutting down server...")
 
-	// The context is used to inform the server it has 5 seconds to finish
-	// the request it is currently handling
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
-	defer cancel()
+	select {
+	case err := <-serverError:
+		log.Printf("listen: %s\n", err)
+	case <-quit:
+		log.Println("Shutting down server...")
+		// The context is used to inform the server it has 5 seconds to finish
+		// the request it is currently handling
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
 
-	if err := srv.Shutdown(ctx); err != nil {
-		log.Fatal("Server forced to shutdown:", err)
+		if err := srv.Shutdown(ctx); err != nil {
+			srv.Close()
+			log.Fatal("Server forced to shutdown:", err)
+		}
 	}
 
 	log.Println("Server exiting")