// Copyright (c) 2021 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// The tshello server demonstrates how to use Tailscale as a library.
package main
import (
"crypto/tls"
"flag"
"fmt"
"html"
"log"
"net/http"
"strings"
"tailscale.com/client/tailscale"
"tailscale.com/tsnet"
)
var (
addr = flag.String("addr", ":80", "address to listen on")
)
func main() {
flag.Parse()
s := new(tsnet.Server)
defer s.Close()
ln, err := s.Listen("tcp", *addr)
if err != nil {
log.Fatal(err)
}
defer ln.Close()
if *addr == ":443" {
ln = tls.NewListener(ln, &tls.Config{
GetCertificate: tailscale.GetCertificate,
})
}
log.Fatal(http.Serve(ln, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
who, err := tailscale.WhoIs(r.Context(), r.RemoteAddr)
if err != nil {
http.Error(w, err.Error(), 500)
return
}
fmt.Fprintf(w, "Hello, world!
\n")
fmt.Fprintf(w, "You are %s from %s (%s)
",
html.EscapeString(who.UserProfile.LoginName),
html.EscapeString(firstLabel(who.Node.ComputedName)),
r.RemoteAddr)
})))
}
func firstLabel(s string) string {
if i := strings.Index(s, "."); i != -1 {
return s[:i]
}
return s
}