go simpleserver

README.md

Simple Server

This is a small golang program to serve files via http. The files are restricted to the base directory and its children, or a specified directory. You will see a nice directory listing in the browser. It is meant to be used with *.html, *.png, and other files.

To use it: go build && ./simpleserver ..

Then in your browser, navigate to: http://localhost:8000/

_go simpleserver

. (dummy file to change name of gist)

simpleserver.go

package main

// Serve a web page for files.
//
// To see cache behavior: curl -I localhost:8000/foo
// See also: http FileServer example (DotFileHiding, StripPrefix), and Dir().

import (
	"log"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

const port = ":8001"

var baseDir = "."

// Serve a file
func handleServeFile(w http.ResponseWriter, r *http.Request) {

	// log.Printf("Got a request for serve file:%s\n", r.URL.Path)
	// log.Printf("  Method:%s\n", r.Method)
	// log.Printf("  Path:%s\n", r.URL.Path)
	// log.Printf("  Query:%v\n", r.URL.Query())

	file := r.URL.Path

	// We guard against "..", which also disallows filename having two dots.
	// This is actually unnecessary since http.ServerFile also does a check, and
	// their check is smarter.
	if strings.Contains(file, "..") {
		log.Println("Disallowed:" + file)
		w.WriteHeader(http.StatusNotFound)
		return
	}

	path := filepath.Join(baseDir, file)
	log.Println(path)
	http.ServeFile(w, r, path)
}

func main() {
	log.SetFlags(log.Flags() | log.Lmicroseconds)

	if len(os.Args) == 2 {
		baseDir = os.Args[1]
	} else if len(os.Args) != 1 {
		log.Fatalf("Expecting either no arguments or the base directory")
	}

	// We must specify the baseDir as absolute, because ServeFile will reject
	// requests where r.URL.Path contains a ".." path element.
	log.Printf("Using as base directory::%s\n", baseDir)
	var err error
	baseDir, err = filepath.Abs(baseDir)
	if err != nil {
		log.Fatal("Cannot get absolute directory for the base directory:", baseDir)
	}
	log.Printf("Using as base directory::%s\n", baseDir)
	log.Printf("About to serve on port:%s\n", port)

	http.HandleFunc("/", handleServeFile)
	if err := http.ListenAndServe(port, nil); err != nil {
		panic(err)
	}
}