feat: add port to global options for default node

- add global tailscale.port option
- added proper handling for default node:
  If no name is specified it used hardcoded string "caddy" but the docs
  say that it is using the binary name

Signed-off-by: khartahk <[email protected]>

Author: khartahk

app.go

@@ -44,6 +44,9 @@ type App struct {
 	// Tags to apply to all nodes when registered.
 	Tags []string `json:"tags,omitempty" caddy:"namespace=tailscale.tags"`
 
+	// Port specifies the default UDP port for tsnet. When unset (0), tsnet will pick a random available port.
+	Port uint16 `json:"port,omitempty" caddy:"namespace=tailscale.port"`
+
 	// Nodes is a map of per-node configuration which overrides global options.
 	Nodes map[string]Node `json:"nodes,omitempty" caddy:"namespace=tailscale"`
 
@@ -150,6 +153,16 @@ func parseAppConfig(d *caddyfile.Dispenser, _ any) (any, error) {
 			}
 		case "tags":
 			app.Tags = d.RemainingArgs()
+		case "port":
+			if d.NextArg() {
+				v, err := strconv.ParseUint(d.Val(), 10, 16)
+				if err != nil {
+					return nil, d.WrapErr(err)
+				}
+				app.Port = uint16(v)
+			} else {
+				app.Port = 0
+			}
 		default:
 			node, err := parseNodeConfig(d)
 			if app.Nodes == nil {

module.go

@@ -66,6 +66,11 @@ func getTCPListener(c context.Context, network string, host string, portRange st
 		network = "tcp"
 	}
 
+	// If host is empty (bind tailscale/), use default node name from binary name
+	if host == "" {
+		host = getDefaultNodeName()
+	}
+
 	// Get node reference for this listener (increments node reference count)
 	node, err := getNode(ctx, host)
 	if err != nil {
@@ -117,6 +122,11 @@ func getTLSListener(c context.Context, network string, host string, portRange st
 		network = "tcp"
 	}
 
+	// If host is empty (bind tailscale/), use default node name from binary name
+	if host == "" {
+		host = getDefaultNodeName()
+	}
+
 	// Get node reference for this listener (increments node reference count)
 	node, err := getNode(ctx, host)
 	if err != nil {
@@ -173,6 +183,11 @@ func getUDPListener(c context.Context, network string, host string, portRange st
 		network = "udp"
 	}
 
+	// If host is empty (bind tailscale/), use default node name from binary name
+	if host == "" {
+		host = getDefaultNodeName()
+	}
+
 	// Get node reference for this listener (increments node reference count)
 	node, err := getNode(ctx, host)
 	if err != nil {
@@ -252,6 +267,12 @@ var nodes = caddy.NewUsagePool()
 // This ensures listeners are properly closed when removed from configuration.
 var tailscaleListeners = caddy.NewUsagePool()
 
+// getDefaultNodeName returns the default node name when none is specified.
+// It uses the binary name (without path) as the default.
+func getDefaultNodeName() string {
+	return filepath.Base(os.Args[0])
+}
+
 // getNode returns a tailscale node for Caddy apps to interface with.
 //
 // The specified name will be used to lookup the node configuration from the tailscale caddy app,
@@ -366,7 +387,7 @@ func getPort(name string, app *App) uint16 {
 		return node.Port
 	}
 
-	return 0
+	return app.Port
 }
 
 func getStateDir(name string, app *App) (string, error) {