fix udp loadbalancer on mac

Change-Id: I24c5e8334af622feb4dedb13b63e0446c1747329

Author: aojea

pkg/loadbalancer/tunnel.go

@@ -99,6 +99,7 @@ func (t *tunnelManager) removeTunnels(containerName string) error {
 // tunnel listens on localIP:localPort and proxies the connection to remoteIP:remotePort
 type tunnel struct {
 	listener   net.Listener
+	udpConn    *net.UDPConn
 	localIP    string
 	localPort  string
 	protocol   string
@@ -118,35 +119,55 @@ func NewTunnel(localIP, localPort, protocol, remoteIP, remotePort string) *tunne
 
 func (t *tunnel) Start() error {
 	klog.Infof("Starting tunnel on %s", net.JoinHostPort(t.localIP, t.localPort))
-	ln, err := net.Listen(t.protocol, net.JoinHostPort(t.localIP, t.localPort))
-	if err != nil {
-		return err
-	}
-
-	t.listener = ln
-
-	go func() {
-		for {
-			conn, err := ln.Accept()
+	if t.protocol == "udp" {
+		localAddrStr := net.JoinHostPort(t.localIP, t.localPort)
+		udpAddr, err := net.ResolveUDPAddr("udp", localAddrStr)
+		if err != nil {
+			return err
+		}
+		conn, err := net.ListenUDP("udp", udpAddr)
+		t.udpConn = conn
+		go func() {
+			err = t.handleConnection(conn)
 			if err != nil {
-				klog.Infof("unexpected error listening: %v", err)
-				return
-			} else {
-				go func() {
-					err := t.handleConnection(conn)
-					if err != nil {
-						klog.Infof("unexpected error on connection: %v", err)
-					}
-				}()
+				klog.Infof("unexpected error on connection: %v", err)
 			}
+		}()
+
+	} else {
+		ln, err := net.Listen(t.protocol, net.JoinHostPort(t.localIP, t.localPort))
+		if err != nil {
+			return err
 		}
-	}()
+
+		t.listener = ln
+
+		go func() {
+			for {
+				conn, err := ln.Accept()
+				if err != nil {
+					klog.Infof("unexpected error listening: %v", err)
+					return
+				} else {
+					go func() {
+						err := t.handleConnection(conn)
+						if err != nil {
+							klog.Infof("unexpected error on connection: %v", err)
+						}
+					}()
+				}
+			}
+		}()
+	}
 	return nil
 }
 
 func (t *tunnel) Stop() error {
 	if t.listener != nil {
-		return t.listener.Close()
+		_ = t.listener.Close()
+	}
+	if t.udpConn != nil {
+		_ = t.udpConn.Close()
 	}
 	return nil
 }