Share directory via HTTP, similar to python -m SimpleHTTPServer - webshare

.gitignore

/webshare

go.mod

module gist.github.com/miku/b5d856ef96a1f78530d8abbeb8f4d13d

go 1.15

require github.com/mdp/qrterminal/v3 v3.0.0 // indirect

go.sum

github.com/mattn/go-colorable v0.1.2/go.mod h1:U0ppj6V5qS13XJ6of8GYAs25YV2eR4EVcfRqFIhoBtE=
github.com/mattn/go-isatty v0.0.8/go.mod h1:Iq45c/XA43vh69/j3iqttzPXn0bhXyGjM0Hdxcsrc5s=
github.com/mdp/qrterminal v1.0.1 h1:07+fzVDlPuBlXS8tB0ktTAyf+Lp1j2+2zK3fBOL5b7c=
github.com/mdp/qrterminal v1.0.1/go.mod h1:Z33WhxQe9B6CdW37HaVqcRKzP+kByF3q/qLxOGe12xQ=
github.com/mdp/qrterminal/v3 v3.0.0 h1:ywQqLRBXWTktytQNDKFjhAvoGkLVN3J2tAFZ0kMd9xQ=
github.com/mdp/qrterminal/v3 v3.0.0/go.mod h1:NJpfAs7OAm77Dy8EkWrtE4aq+cE6McoLXlBqXQEwvE0=
golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
rsc.io/qr v0.2.0 h1:6vBLea5/NRMVTz8V66gipeLycZMl/+UlFmk8DvqQ6WY=
rsc.io/qr v0.2.0/go.mod h1:IF+uZjkb9fqyeF/4tlBoynqmQxUoPfWEKh921coOuXs=

Makefile

.PHONY: clean install

webshare: webshare.go
	go build -o $@ $<

clean:
	rm -f webshare
	rm -f webshare.1

webshare.1: webshare.md
	pandoc $< -s -t man > $@

PREFIX = $(HOME)
BINDIR = $(PREFIX)/bin
MANDIR = $(PREFIX)/man/man1

install: webshare webshare.1
	install -d $(BINDIR) $(MANDIR)
	install webshare $(BINDIR)
	install webshare.1 $(MANDIR)

webshare.go

// webshare serves the current directory on port 3000.
package main

import (
	"flag"
	"fmt"
	"log"
	"net"
	"net/http"
	"os"
	"path"
	"strings"

	"github.com/mdp/qrterminal"
)

var (
	port      = flag.Int("p", 3000, "port to listen on")
	directory = flag.String("d", ".", "directory to share")
	qrPrefix  = flag.String("q", "192", "ip addr prefix to print qr code for")
)

var privateIPBlocks []*net.IPNet

func init() {
	for _, cidr := range []string{
		"127.0.0.0/8",    // IPv4 loopback
		"10.0.0.0/8",     // RFC1918
		"172.16.0.0/12",  // RFC1918
		"192.168.0.0/16", // RFC1918
		"169.254.0.0/16", // RFC3927 link-local
		"::1/128",        // IPv6 loopback
		"fe80::/10",      // IPv6 link-local
		"fc00::/7",       // IPv6 unique local addr
	} {
		_, block, err := net.ParseCIDR(cidr)
		if err != nil {
			panic(fmt.Errorf("parse error on %q: %v", cidr, err))
		}
		privateIPBlocks = append(privateIPBlocks, block)
	}
}

func isPrivateIP(ip net.IP) bool {
	if ip.IsLoopback() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
		return true
	}

	for _, block := range privateIPBlocks {
		if block.Contains(ip) {
			return true
		}
	}
	return false
}

func loggingHandler(h http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		log.Println(r.RemoteAddr, r.Method, r.URL.Path)

		fn := path.Join(".", r.URL.Path)
		file, err := os.Open(fn)
		if err == nil {
			defer file.Close()
			fi, err := file.Stat()
			if err == nil {
				log.Printf("%s [%d]", file.Name(), fi.Size())
			}
		}

		h.ServeHTTP(w, r)
	})
}

func main() {
	flag.Parse()

	fs := http.FileServer(http.Dir(*directory))
	http.Handle("/", loggingHandler(fs))

	addrs, err := net.InterfaceAddrs()
	if err != nil {
		log.Fatal(err)
	}
	config := qrterminal.Config{
		Level:     qrterminal.M,
		Writer:    os.Stdout,
		BlackChar: qrterminal.WHITE,
		WhiteChar: qrterminal.BLACK,
		QuietZone: 1,
	}

	for _, addr := range addrs {
		if ipnet, ok := addr.(*net.IPNet); ok {
			if ipnet.IP.To4() != nil {
				mark := "public"
				if isPrivateIP(ipnet.IP) {
					mark = "private"
				}
				link := fmt.Sprintf("http://%s:%d", ipnet.IP.String(), *port)
				log.Printf("%s [%s]", link, mark)
				if strings.HasPrefix(ipnet.IP.String(), *qrPrefix) {
					qrterminal.GenerateWithConfig(link, config)
				}
			}
		}
	}

	if err := http.ListenAndServe(fmt.Sprintf(":%d", *port), nil); err != nil {
		log.Fatal(err)
	}
}

webshare.md

% WEBSHARE(1) % Martin Czygan % November 2018

NAME

webshare - share a directory over HTTP

SYNOPSIS

webshare [-p PORT] [-d DIRECTORY]

DESCRIPTION

Share a directory over HTTP.