Skip to content

Instantly share code, notes, and snippets.

Last active January 17, 2024 04:37
Star You must be signed in to star a gist
Save enricofoltran/10b4a980cd07cb02836f70a4ab3e72d7 to your computer and use it in GitHub Desktop.
A simple golang web server with basic logging, tracing, health check, graceful shutdown and zero dependencies
package main
import (
type key int
const (
requestIDKey key = 0
var (
listenAddr string
healthy int32
func main() {
flag.StringVar(&listenAddr, "listen-addr", ":5000", "server listen address")
logger := log.New(os.Stdout, "http: ", log.LstdFlags)
logger.Println("Server is starting...")
router := http.NewServeMux()
router.Handle("/", index())
router.Handle("/healthz", healthz())
nextRequestID := func() string {
return fmt.Sprintf("%d", time.Now().UnixNano())
server := &http.Server{
Addr: listenAddr,
Handler: tracing(nextRequestID)(logging(logger)(router)),
ErrorLog: logger,
ReadTimeout: 5 * time.Second,
WriteTimeout: 10 * time.Second,
IdleTimeout: 15 * time.Second,
done := make(chan bool)
quit := make(chan os.Signal, 1)
signal.Notify(quit, os.Interrupt)
go func() {
logger.Println("Server is shutting down...")
atomic.StoreInt32(&healthy, 0)
ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
defer cancel()
if err := server.Shutdown(ctx); err != nil {
logger.Fatalf("Could not gracefully shutdown the server: %v\n", err)
logger.Println("Server is ready to handle requests at", listenAddr)
atomic.StoreInt32(&healthy, 1)
if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
logger.Fatalf("Could not listen on %s: %v\n", listenAddr, err)
logger.Println("Server stopped")
func index() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.Error(w, http.StatusText(http.StatusNotFound), http.StatusNotFound)
w.Header().Set("Content-Type", "text/plain; charset=utf-8")
w.Header().Set("X-Content-Type-Options", "nosniff")
fmt.Fprintln(w, "Hello, World!")
func healthz() http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if atomic.LoadInt32(&healthy) == 1 {
func logging(logger *log.Logger) func(http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
defer func() {
requestID, ok := r.Context().Value(requestIDKey).(string)
if !ok {
requestID = "unknown"
logger.Println(requestID, r.Method, r.URL.Path, r.RemoteAddr, r.UserAgent())
next.ServeHTTP(w, r)
func tracing(nextRequestID func() string) func(http.Handler) http.Handler {
return func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
requestID := r.Header.Get("X-Request-Id")
if requestID == "" {
requestID = nextRequestID()
ctx := context.WithValue(r.Context(), requestIDKey, requestID)
w.Header().Set("X-Request-Id", requestID)
next.ServeHTTP(w, r.WithContext(ctx))
Copy link

This is cash-money awesome! Thank you for sharing this!

Copy link

rpeets commented Jul 11, 2021

Any pointers on how to include the http.statuscode in logs, please?

Copy link

Thanks for sharing

Copy link

pococms commented Aug 25, 2022

I'd like to use this code in an open source static site generator. It's MIT licensed. Can I use this code, or at least a version of it? And if so, what's your license for it? Thanks!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment