Simple HTTP Middleware

middleware.go

package main

import (
	"fmt"
	"log"
	"net/http"
)

func myHandler(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("myHandler\n"))
}

type middleware []http.Handler

func (m *middleware) Add(handler http.Handler) {
	*m = append(*m, handler)
}

func (m middleware) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	for _, handler := range m {
		handler.ServeHTTP(w, r)
	}
}

func main() {
	mux := http.NewServeMux()
	mw := make(middleware, 0)

	mw.Add(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write([]byte("test middleware\n"))
	}))

	mw.Add(http.HandlerFunc(myHandler))

	mux.Handle("/", mw)

	log.Fatal(http.ListenAndServe(":3000", mux))
	fmt.Println("Server is running...")
}