server.go

package main

import (
	"context"
	"github.com/gin-gonic/gin"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strconv"
	"syscall"
	"time"
)

func serve(r *gin.Engine) {
	Addr := os.Getenv("GIN_Addr") + ":" + os.Getenv("GIN_PORT")
	ShutdownTimeoutStr := os.Getenv("GIN_Shutdown_Timeout")
	ShutdownTimeout, _ := strconv.Atoi(ShutdownTimeoutStr)
	srv := &http.Server{
		Addr:           Addr,
		Handler:        r,
		ReadTimeout:    3600 * time.Second,
		WriteTimeout:   3600 * time.Second,
		MaxHeaderBytes: 1 << 20,
	}
	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)
	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
	<-quit
	log.Println("Shutdown Server ...")

	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(ShutdownTimeout)*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 " + ShutdownTimeoutStr + " seconds.")
	}
	log.Println("Server exiting")
}