From e1bc4d2eba243be923ec5d9b454558a13e126f12 Mon Sep 17 00:00:00 2001
From: Daniel Smith <dbsmith@google.com>
Date: Thu, 12 Jun 2014 17:18:19 -0700
Subject: [PATCH] Port 2223 is in use on my machine sometimes, so this test was
 flaky.

---
 pkg/proxy/proxier.go      | 25 ++++++++++++++++++----
 pkg/proxy/proxier_test.go | 45 ++++++++++++++++++++++-----------------
 2 files changed, 46 insertions(+), 24 deletions(-)

diff --git a/pkg/proxy/proxier.go b/pkg/proxy/proxier.go
index 7eed34a050d..eaf7aedf6bb 100644
--- a/pkg/proxy/proxier.go
+++ b/pkg/proxy/proxier.go
@@ -90,16 +90,33 @@ func (proxier Proxier) AcceptHandler(service string, listener net.Listener) {
 // AddService starts listening for a new service on a given port.
 func (proxier Proxier) AddService(service string, port int) error {
 	// Make sure we can start listening on the port before saying all's well.
-	ln, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", port))
 	if err != nil {
 		return err
 	}
-	log.Printf("Listening for %s on %d", service, port)
-	// If that succeeds, start the accepting loop.
-	go proxier.AcceptHandler(service, ln)
+	proxier.addServiceCommon(service, l)
 	return nil
 }
 
+// addService starts listening for a new service, returning the port it's using.
+// For testing on a system with unknown ports used.
+func (proxier Proxier) addServiceOnUnusedPort(service string) (string, error) {
+	// Make sure we can start listening on the port before saying all's well.
+	l, err := net.Listen("tcp", ":")
+	if err != nil {
+		return "", err
+	}
+	proxier.addServiceCommon(service, l)
+	_, port, err := net.SplitHostPort(l.Addr().String())
+	return port, nil
+}
+
+func (proxier Proxier) addServiceCommon(service string, l net.Listener) {
+	log.Printf("Listening for %s on %s", service, l.Addr().String())
+	// If that succeeds, start the accepting loop.
+	go proxier.AcceptHandler(service, l)
+}
+
 func (proxier Proxier) OnUpdate(services []api.Service) {
 	log.Printf("Received update notice: %+v", services)
 	for _, service := range services {
diff --git a/pkg/proxy/proxier_test.go b/pkg/proxy/proxier_test.go
index f3eba3b6daa..7c917803252 100644
--- a/pkg/proxy/proxier_test.go
+++ b/pkg/proxy/proxier_test.go
@@ -25,37 +25,42 @@ import (
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 )
 
-// a simple echoServer that only accept one connection
-func echoServer(addr string) error {
+// a simple echoServer that only accepts one connection. Returns port actually
+// being listened on, or an error.
+func echoServer(t *testing.T, addr string) (string, error) {
 	l, err := net.Listen("tcp", addr)
 	if err != nil {
-		return fmt.Errorf("failed to start echo service: %v", err)
+		return "", fmt.Errorf("failed to start echo service: %v", err)
 	}
-	defer l.Close()
-	conn, err := l.Accept()
-	if err != nil {
-		return fmt.Errorf("failed to accept new conn to echo service: %v", err)
-	}
-	io.Copy(conn, conn)
-	conn.Close()
-	return nil
+	go func() {
+		defer l.Close()
+		conn, err := l.Accept()
+		if err != nil {
+			t.Errorf("failed to accept new conn to echo service: %v", err)
+		}
+		io.Copy(conn, conn)
+		conn.Close()
+	}()
+	_, port, err := net.SplitHostPort(l.Addr().String())
+	return port, err
 }
 
 func TestProxy(t *testing.T) {
-	go func() {
-		if err := echoServer("127.0.0.1:2222"); err != nil {
-			t.Fatal(err)
-		}
-	}()
+	port, err := echoServer(t, "127.0.0.1:")
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	lb := NewLoadBalancerRR()
-	lb.OnUpdate([]api.Endpoints{{"echo", []string{"127.0.0.1:2222"}}})
+	lb.OnUpdate([]api.Endpoints{{"echo", []string{net.JoinHostPort("127.0.0.1", port)}}})
 
 	p := NewProxier(lb)
-	if err := p.AddService("echo", 2223); err != nil {
-		t.Fatalf("error adding new service: %v", err)
+
+	proxyPort, err := p.addServiceOnUnusedPort("echo")
+	if err != nil {
+		t.Fatalf("error adding new service: %#v", err)
 	}
-	conn, err := net.Dial("tcp", "127.0.0.1:2223")
+	conn, err := net.Dial("tcp", net.JoinHostPort("127.0.0.1", proxyPort))
 	if err != nil {
 		t.Fatalf("error connecting to proxy: %v", err)
 	}