chore(cmd): clean up commands (#9705)

Move infrastructure related commands to under `cmd/infra` and
development stuff to `cmd/dev`. The default build command builds the
regular user facing binaries: syncthing, stdiscosrv, and strelaysrv.

cmd/dev/stfinddevice/main.go

@@ -0,0 +1,110 @@
+// Copyright (C) 2014 The Syncthing Authors.
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+package main
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"flag"
+	"fmt"
+	"net/url"
+	"os"
+	"time"
+
+	_ "github.com/syncthing/syncthing/lib/automaxprocs"
+	"github.com/syncthing/syncthing/lib/config"
+	"github.com/syncthing/syncthing/lib/discover"
+	"github.com/syncthing/syncthing/lib/events"
+	"github.com/syncthing/syncthing/lib/protocol"
+)
+
+var timeout = 5 * time.Second
+
+func main() {
+	var server string
+
+	flag.StringVar(&server, "server", "", "Announce server (blank for default set)")
+	flag.DurationVar(&timeout, "timeout", timeout, "Query timeout")
+	flag.Usage = usage
+	flag.Parse()
+
+	if flag.NArg() != 1 {
+		flag.Usage()
+		os.Exit(64)
+	}
+
+	id, err := protocol.DeviceIDFromString(flag.Args()[0])
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	if server != "" {
+		checkServers(id, server)
+	} else {
+		checkServers(id, config.DefaultDiscoveryServers...)
+	}
+}
+
+type checkResult struct {
+	server    string
+	addresses []string
+	error
+}
+
+func checkServers(deviceID protocol.DeviceID, servers ...string) {
+	t0 := time.Now()
+	resc := make(chan checkResult)
+	for _, srv := range servers {
+		srv := srv
+		go func() {
+			res := checkServer(deviceID, srv)
+			res.server = srv
+			resc <- res
+		}()
+	}
+
+	for range servers {
+		res := <-resc
+
+		u, _ := url.Parse(res.server)
+		fmt.Printf("%s (%v):\n", u.Host, time.Since(t0))
+
+		if res.error != nil {
+			fmt.Println("  " + res.error.Error())
+		}
+		for _, addr := range res.addresses {
+			fmt.Println("  address:", addr)
+		}
+	}
+}
+
+func checkServer(deviceID protocol.DeviceID, server string) checkResult {
+	disco, err := discover.NewGlobal(server, tls.Certificate{}, nil, events.NoopLogger, nil)
+	if err != nil {
+		return checkResult{error: err}
+	}
+
+	res := make(chan checkResult, 1)
+
+	time.AfterFunc(timeout, func() {
+		res <- checkResult{error: errors.New("timeout")}
+	})
+
+	go func() {
+		addresses, err := disco.Lookup(context.Background(), deviceID)
+		res <- checkResult{addresses: addresses, error: err}
+	}()
+
+	return <-res
+}
+
+func usage() {
+	fmt.Printf("Usage:\n\t%s [options] <device ID>\n\nOptions:\n", os.Args[0])
+	flag.PrintDefaults()
+}