Go http server with graceful shutdown

main.go

package main

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

func main() {
	var srv http.Server

	idleConnsClosed := make(chan struct{})
	go func() {
		sigint := make(chan os.Signal, 1)

		// interrupt signal sent from terminal
		signal.Notify(sigint, os.Interrupt)
		// sigterm signal sent from kubernetes
		signal.Notify(sigint, syscall.SIGTERM)

		<-sigint

		// We received an interrupt signal, shut down.
		if err := srv.Shutdown(context.Background()); err != nil {
			// Error from closing listeners, or context timeout:
			log.Printf("HTTP server Shutdown: %v", err)
		}
		close(idleConnsClosed)
	}()

	if err := srv.ListenAndServe(); err != http.ErrServerClosed {
		// Error starting or closing listener:
		log.Printf("HTTP server ListenAndServe: %v", err)
	}

	<-idleConnsClosed
}