Simple golang webserver with custom Socket Option SO_REUSEPORT to run multiple processes on the same port

main.go

package main

import (
	"context"
	"fmt"
	"log"
	"net"
	"net/http"
	"os"
	"syscall"
	"time"

	"golang.org/x/sys/unix"
)

func greet(w http.ResponseWriter, r *http.Request) {
	fmt.Fprintf(w, "Hello World! pid=%s time=%s", os.Getpid(), time.Now())
}

func main() {

	http.HandleFunc("/", greet)
	// http.ListenAndServe(":8080", nil)

	server := http.Server{Addr: ":8080", Handler: nil}

	// set socket option SO_REUSEPORT to let multiple processes listen on the same port
	lc := net.ListenConfig{
		Control: func(network, address string, c syscall.RawConn) error {
			var opErr error
			err := c.Control(func(fd uintptr) {
				opErr = unix.SetsockoptInt(int(fd), unix.SOL_SOCKET, unix.SO_REUSEPORT, 1)
			})
			if err != nil {
				return err
			}
			return opErr
		},
	}

	ln, err := lc.Listen(context.Background(), "tcp", server.Addr)
	if err != nil {
		log.Fatal(err)
	}

	err = server.Serve(ln)

	if err != nil {
		log.Fatal(err)
	}
}