cmd/syncthing, lib/config: Update default config creation (#5492)

Also remove dead code in config.Wrapper.

cmd/syncthing/main.go

@@ -1068,45 +1068,15 @@ func setupGUI(mainService *suture.Supervisor, cfg *config.Wrapper, m *model.Mode
 }
 
 func defaultConfig(cfgFile string) *config.Wrapper {
-	myName, _ := os.Hostname()
+	newCfg := config.NewWithFreePorts(myID)
 
-	var defaultFolder config.FolderConfiguration
-
-	if !noDefaultFolder {
-		l.Infoln("Default folder created and/or linked to new config")
-		defaultFolder = config.NewFolderConfiguration(myID, "default", "Default Folder", fs.FilesystemTypeBasic, locations[locDefFolder])
-	} else {
+	if noDefaultFolder {
 		l.Infoln("We will skip creation of a default folder on first start since the proper envvar is set")
+		return config.Wrap(cfgFile, newCfg)
 	}
 
-	thisDevice := config.NewDeviceConfiguration(myID, myName)
-	thisDevice.Addresses = []string{"dynamic"}
-
-	newCfg := config.New(myID)
-	if !noDefaultFolder {
-		newCfg.Folders = []config.FolderConfiguration{defaultFolder}
-	}
-	newCfg.Devices = []config.DeviceConfiguration{thisDevice}
-
-	port, err := getFreePort("127.0.0.1", 8384)
-	if err != nil {
-		l.Fatalln("get free port (GUI):", err)
-	}
-	newCfg.GUI.RawAddress = fmt.Sprintf("127.0.0.1:%d", port)
-
-	port, err = getFreePort("0.0.0.0", 22000)
-	if err != nil {
-		l.Fatalln("get free port (BEP):", err)
-	}
-	if port == 22000 {
-		newCfg.Options.ListenAddresses = []string{"default"}
-	} else {
-		newCfg.Options.ListenAddresses = []string{
-			fmt.Sprintf("tcp://%s", net.JoinHostPort("0.0.0.0", strconv.Itoa(port))),
-			"dynamic+https://relays.syncthing.net/endpoint",
-		}
-	}
-
+	newCfg.Folders = append(newCfg.Folders, config.NewFolderConfiguration(myID, "default", "Default Folder", fs.FilesystemTypeBasic, locations[locDefFolder]))
+	l.Infoln("Default folder created and/or linked to new config")
 	return config.Wrap(cfgFile, newCfg)
 }
 
@@ -1146,27 +1116,6 @@ func ensureDir(dir string, mode fs.FileMode) {
 	}
 }
 
-// getFreePort returns a free TCP port fort listening on. The ports given are
-// tried in succession and the first to succeed is returned. If none succeed,
-// a random high port is returned.
-func getFreePort(host string, ports ...int) (int, error) {
-	for _, port := range ports {
-		c, err := net.Listen("tcp", fmt.Sprintf("%s:%d", host, port))
-		if err == nil {
-			c.Close()
-			return port, nil
-		}
-	}
-
-	c, err := net.Listen("tcp", host+":0")
-	if err != nil {
-		return 0, err
-	}
-	addr := c.Addr().(*net.TCPAddr)
-	c.Close()
-	return addr.Port, nil
-}
-
 func standbyMonitor() {
 	restartDelay := 60 * time.Second
 	now := time.Now()

lib/config/config.go

@@ -47,6 +47,7 @@ var (
 		util.Address("tcp", net.JoinHostPort("0.0.0.0", strconv.Itoa(DefaultTCPPort))),
 		"dynamic+https://relays.syncthing.net/endpoint",
 	}
+	DefaultGUIPort = 8384
 	// DefaultDiscoveryServersV4 should be substituted when the configuration
 	// contains <globalAnnounceServer>default-v4</globalAnnounceServer>.
 	DefaultDiscoveryServersV4 = []string{
@@ -83,6 +84,31 @@ func New(myID protocol.DeviceID) Configuration {
 	return cfg
 }
 
+func NewWithFreePorts(myID protocol.DeviceID) Configuration {
+	cfg := New(myID)
+
+	port, err := getFreePort("127.0.0.1", DefaultGUIPort)
+	if err != nil {
+		l.Fatalln("get free port (GUI):", err)
+	}
+	cfg.GUI.RawAddress = fmt.Sprintf("127.0.0.1:%d", port)
+
+	port, err = getFreePort("0.0.0.0", DefaultTCPPort)
+	if err != nil {
+		l.Fatalln("get free port (BEP):", err)
+	}
+	if port == DefaultTCPPort {
+		cfg.Options.ListenAddresses = []string{"default"}
+	} else {
+		cfg.Options.ListenAddresses = []string{
+			fmt.Sprintf("tcp://%s", net.JoinHostPort("0.0.0.0", strconv.Itoa(port))),
+			"dynamic+https://relays.syncthing.net/endpoint",
+		}
+	}
+
+	return cfg
+}
+
 func ReadXML(r io.Reader, myID protocol.DeviceID) (Configuration, error) {
 	var cfg Configuration
 
@@ -840,3 +866,23 @@ func filterURLSchemePrefix(addrs []string, prefix string) []string {
 	}
 	return addrs
 }
+
+// tried in succession and the first to succeed is returned. If none succeed,
+// a random high port is returned.
+func getFreePort(host string, ports ...int) (int, error) {
+	for _, port := range ports {
+		c, err := net.Listen("tcp", fmt.Sprintf("%s:%d", host, port))
+		if err == nil {
+			c.Close()
+			return port, nil
+		}
+	}
+
+	c, err := net.Listen("tcp", host+":0")
+	if err != nil {
+		return 0, err
+	}
+	addr := c.Addr().(*net.TCPAddr)
+	c.Close()
+	return addr.Port, nil
+}

lib/config/wrapper.go

@@ -64,7 +64,6 @@ type Wrapper struct {
 
 	deviceMap map[protocol.DeviceID]DeviceConfiguration
 	folderMap map[string]FolderConfiguration
-	replaces  chan Configuration
 	subs      []Committer
 	mut       sync.Mutex
 
@@ -79,7 +78,6 @@ func Wrap(path string, cfg Configuration) *Wrapper {
 		path: path,
 		mut:  sync.NewMutex(),
 	}
-	w.replaces = make(chan Configuration)
 	return w
 }
 
@@ -104,12 +102,6 @@ func (w *Wrapper) ConfigPath() string {
 	return w.path
 }
 
-// Stop stops the Serve() loop. Set and Replace operations will panic after a
-// Stop.
-func (w *Wrapper) Stop() {
-	close(w.replaces)
-}
-
 // Subscribe registers the given handler to be called on any future
 // configuration changes.
 func (w *Wrapper) Subscribe(c Committer) {