hellohttp.go

package main

import (
        "fmt"
        "io"
        "net/http"
        "os"
        "os/signal"
        "runtime/pprof"
        "strconv"
)

type httpHandler struct{}

func (handler *httpHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
        const response = "abcdefghijklmnopqrstuvwxyz"
        w.Header().Add("Content-Type", "text/plain")
        w.Header().Add("Content-Length", strconv.Itoa(len(response)))
        io.WriteString(w, response)
}

func main() {
        profile := false

        if profile {
                f, _ := os.Create("profile.cpu")
                pprof.StartCPUProfile(f)
        }

        go func() {
                c := make(chan os.Signal, 1)
                signal.Notify(c, os.Interrupt)
                <-c

                if profile {
                        pprof.StopCPUProfile()
                }

                fmt.Println("Caught interrupt.. shutting down.")
                os.Exit(0)
        }()

        handler := &httpHandler{}
        server := &http.Server{
                Addr:    "0.0.0.0:8081",
                Handler: handler,
        }
        server.ListenAndServe()
}