Simple HTTP Server in Go Programming Language

simple_server.go

package main

import (
	"net/http"
	"os"
)

func main() {
	port := os.Getenv("PORT")
	if port == "" {
		port = "8080"
	}

	http.HandleFunc("/ping", ping)
	http.ListenAndServe(":"+port, nil)
}

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