Server.go

package main

import (
	"fmt"
	"github.com/gorilla/handlers"
	"log"
	"net/http"
	"os"
	"time"
)

func main() {
	fmt.Println(epoch)
	const homeDir = "/"
	fs := http.FileServer(http.Dir(homeDir))
	http.Handle("/", http.StripPrefix(homeDir, fs))
	log.Println("Listening...")
	_ = http.ListenAndServe(":8443", NoCache(handlers.CompressHandler(fs)))
}

var epoch = time.Unix(0, 0).Format(time.RFC1123)

var noCacheHeaders = map[string]string{
	"Expires":         epoch,
	"Cache-Control":   "no-cache, private, max-age=0",
	"Pragma":          "no-cache",
	"X-Accel-Expires": "0",
}

var etagHeaders = []string{
	"ETag",
	"If-Modified-Since",
	"If-Match",
	"If-None-Match",
	"If-Range",
	"If-Unmodified-Since",
}

func NoCache(h http.Handler) http.Handler {
	fn := func(w http.ResponseWriter, r *http.Request) {
		// Delete any ETag headers that may have been set
		for _, v := range etagHeaders {
			if r.Header.Get(v) != "" {
				r.Header.Del(v)
			}
		}

		// Set our NoCache headers
		for k, v := range noCacheHeaders {
			w.Header().Set(k, v)
		}

		h.ServeHTTP(w, r)
	}

	return http.HandlerFunc(fn)
}

func GetFileContentType(out *os.File) (string, error) {

	// Only the first 512 bytes are used to sniff the content type.
	buffer := make([]byte, 512)

	_, err := out.Read(buffer)
	if err != nil {
		return "", err
	}

	// Use the net/http package's handy DectectContentType function. Always returns a valid
	// content-type by returning "application/octet-stream" if no others seemed to match.
	contentType := http.DetectContentType(buffer)

	return contentType, nil
}