Add gracefull shutdown server

backend/main.go

@@ -1,11 +1,15 @@
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"io"
 	"log"
+	"net/http"
 	"os"
+	"os/signal"
+	"syscall"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -48,4 +52,28 @@ func main() {
 
 	router := gin.Default()
 	router.GET("/health", hc.HealthCheckHandler())
+
+	//Server configuration
+	var server *http.Server
+
+	// Wait for interrupt signal to gracefully shutdown the server with
+	// a timeout of 5 seconds.
+	quit := make(chan os.Signal, 1)
+	// 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, os.Interrupt)
+	<-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 := server.Shutdown(ctx); err != nil {
+		log.Fatal("Server forced to shutdown:", err)
+	}
+
+	log.Println("Server exiting")
 }