serve.go

/*
Simple static file server in go
Usage:
	-p="8100"  port to serve on
	-d="."     the directory of static files to host
	-c         enable cache
	-4         ipv4 only
	-6         ipv6 only

Navigating to http://localhost:8100 will display the index.html or directory
listing file.
*/
package main

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

type appHandler struct {
	http.Handler
	Cache      bool
	FileServer http.Handler
}

func (h *appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if h.Cache {
		w.Header().Set("Cache-Control", "public, max-age=7776000")
	} else {
		w.Header().Set("Cache-Control", "no-cache")
	}
	h.FileServer.ServeHTTP(w, r)
}

func main() {
	port := flag.String("p", "8100", "port to serve on")
	directory := flag.String("d", ".", "the directory of static file to host")
	cache := flag.Bool("c", false, "use cache")
	ipv4 := flag.Bool("4", false, "use ipv4 only")
	ipv6 := flag.Bool("6", false, "use ipv6 only")
	flag.Parse()

	if *ipv4 && *ipv6 {
		log.Fatal("Choose either -4 or -6")
	}

	h := &appHandler{
		Cache:      *cache,
		FileServer: http.FileServer(http.Dir((*directory))),
	}

	server := &http.Server{
		Handler: h,
	}

	family := "tcp"
	log.Printf("Serving %s on HTTP port: %s\n", *directory, *port)
	if *ipv6 {
		family = "tcp6"
	} else if *ipv4 {
		family = "tcp4"
	}

	l, err := net.Listen(family, ":"+*port)
	if err != nil {
		log.Fatal(err)
	}
	log.Fatal(server.Serve(l))
}