tailscale/net/dnsfallback/update-dns-fallbacks.go

49 lines
1.0 KiB
Go

// 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.
//go:build ignore
// +build ignore
package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
"tailscale.com/tailcfg"
)
func main() {
res, err := http.Get("https://login.tailscale.com/derpmap/default")
if err != nil {
log.Fatal(err)
}
if res.StatusCode != 200 {
res.Write(os.Stderr)
os.Exit(1)
}
dm := new(tailcfg.DERPMap)
if err := json.NewDecoder(res.Body).Decode(dm); err != nil {
log.Fatal(err)
}
for rid, r := range dm.Regions {
// Names misleading to check into git, as this is a
// static snapshot and doesn't reflect the live DERP
// map.
r.RegionCode = fmt.Sprintf("r%d", rid)
r.RegionName = r.RegionCode
}
out, err := json.MarshalIndent(dm, "", "\t")
if err != nil {
log.Fatal(err)
}
if err := ioutil.WriteFile("dns-fallback-servers.json", out, 0644); err != nil {
log.Fatal(err)
}
}