Merge pull request #42278 from marun/fed-api-fixture

Automatic merge from submit-queue (batch tested with PRs 42728, 42278)

[Federation] Create integration test fixture for api

This PR factors a reusable fixture for the federation api server out of the existing integration test.

Targets #40705

cc: @kubernetes/sig-federation-pr-reviews

cmd/hyperkube/federation-apiserver.go

@@ -17,6 +17,7 @@ limitations under the License.
 package main
 
 import (
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app"
 	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app/options"
 )
@@ -30,7 +31,7 @@ func NewFederationAPIServer() *Server {
 		SimpleUsage: "federation-apiserver",
 		Long:        "The API entrypoint for the federation control plane",
 		Run: func(_ *Server, args []string) error {
-			return app.Run(s)
+			return app.Run(s, wait.NeverStop)
 		},
 	}
 	s.AddFlags(hks.Flags())

federation/cmd/federation-apiserver/BUILD

@@ -23,6 +23,7 @@ go_library(
         "//federation/cmd/federation-apiserver/app/options:go_default_library",
         "//pkg/version/verflag:go_default_library",
         "//vendor:github.com/spf13/pflag",
+        "//vendor:k8s.io/apimachinery/pkg/util/wait",
         "//vendor:k8s.io/apiserver/pkg/util/flag",
         "//vendor:k8s.io/apiserver/pkg/util/logs",
     ],

federation/cmd/federation-apiserver/apiserver.go

@@ -24,6 +24,7 @@ import (
 	"os"
 	"time"
 
+	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apiserver/pkg/util/flag"
 	"k8s.io/apiserver/pkg/util/logs"
 	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app"
@@ -45,7 +46,7 @@ func main() {
 
 	verflag.PrintAndExitIfRequested()
 
-	if err := app.Run(s); err != nil {
+	if err := app.Run(s, wait.NeverStop); err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}

federation/cmd/federation-apiserver/app/BUILD

@@ -67,7 +67,6 @@ go_library(
         "//vendor:k8s.io/apimachinery/pkg/runtime/schema",
         "//vendor:k8s.io/apimachinery/pkg/util/errors",
         "//vendor:k8s.io/apimachinery/pkg/util/sets",
-        "//vendor:k8s.io/apimachinery/pkg/util/wait",
         "//vendor:k8s.io/apiserver/pkg/admission",
         "//vendor:k8s.io/apiserver/pkg/registry/generic",
         "//vendor:k8s.io/apiserver/pkg/registry/rest",

federation/cmd/federation-apiserver/app/server.go

@@ -34,7 +34,6 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	utilerrors "k8s.io/apimachinery/pkg/util/errors"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/apiserver/pkg/admission"
 	genericapiserver "k8s.io/apiserver/pkg/server"
 	"k8s.io/apiserver/pkg/server/filters"
@@ -67,8 +66,20 @@ cluster's shared state through which all other components interact.`,
 	return cmd
 }
 
-// Run runs the specified APIServer.  This should never exit.
-func Run(s *options.ServerRunOptions) error {
+// Run runs the specified APIServer.  It only returns if stopCh is closed
+// or one of the ports cannot be listened on initially.
+func Run(s *options.ServerRunOptions, stopCh <-chan struct{}) error {
+	err := NonBlockingRun(s, stopCh)
+	if err != nil {
+		return err
+	}
+	<-stopCh
+	return nil
+}
+
+// NonBlockingRun runs the specified APIServer and configures it to
+// stop with the given channel.
+func NonBlockingRun(s *options.ServerRunOptions, stopCh <-chan struct{}) error {
 	// set defaults
 	if err := s.GenericServerRunOptions.DefaultAdvertiseAddress(s.SecureServing, s.InsecureServing); err != nil {
 		return err
@@ -223,8 +234,11 @@ func Run(s *options.ServerRunOptions) error {
 	//	installBatchAPIs(m, genericConfig.RESTOptionsGetter)
 	//	installAutoscalingAPIs(m, genericConfig.RESTOptionsGetter)
 
-	sharedInformers.Start(wait.NeverStop)
-	return m.PrepareRun().Run(wait.NeverStop)
+	err = m.PrepareRun().NonBlockingRun(stopCh)
+	if err == nil {
+		sharedInformers.Start(stopCh)
+	}
+	return err
 }
 
 // PostProcessSpec adds removed definitions for backward compatibility

staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go

@@ -190,18 +190,43 @@ func (s *GenericAPIServer) PrepareRun() preparedGenericAPIServer {
 // Run spawns the http servers (secure and insecure). It only returns if stopCh is closed
 // or one of the ports cannot be listened on initially.
 func (s preparedGenericAPIServer) Run(stopCh <-chan struct{}) error {
+	err := s.NonBlockingRun(stopCh)
+	if err != nil {
+		return err
+	}
+
+	<-stopCh
+	return nil
+}
+
+// NonBlockingRun spawns the http servers (secure and insecure). An error is
+// returned if either of the ports cannot be listened on.
+func (s preparedGenericAPIServer) NonBlockingRun(stopCh <-chan struct{}) error {
+	// Use an internal stop channel to allow cleanup of the listeners on error.
+	internalStopCh := make(chan struct{})
+
 	if s.SecureServingInfo != nil && s.Handler != nil {
-		if err := s.serveSecurely(stopCh); err != nil {
+		if err := s.serveSecurely(internalStopCh); err != nil {
+			close(internalStopCh)
 			return err
 		}
 	}
 
 	if s.InsecureServingInfo != nil && s.InsecureHandler != nil {
-		if err := s.serveInsecurely(stopCh); err != nil {
+		if err := s.serveInsecurely(internalStopCh); err != nil {
+			close(internalStopCh)
 			return err
 		}
 	}
 
+	// Now that both listeners have bound successfully, it is the
+	// responsibility of the caller to close the provided channel to
+	// ensure cleanup.
+	go func() {
+		<-stopCh
+		close(internalStopCh)
+	}()
+
 	s.RunPostStartHooks()
 
 	// err == systemd.SdNotifyNoSocket when not running on a systemd system
@@ -209,7 +234,6 @@ func (s preparedGenericAPIServer) Run(stopCh <-chan struct{}) error {
 		glog.Errorf("Unable to send systemd daemon successful start message: %v\n", err)
 	}
 
-	<-stopCh
 	return nil
 }
 

test/integration/examples/apiserver_test.go

@@ -56,20 +56,6 @@ var groupVersionForDiscovery = metav1.GroupVersionForDiscovery{
 	Version:      groupVersion.Version,
 }
 
-func localPort() (int, error) {
-	l, err := net.Listen("tcp", ":0")
-	if err != nil {
-		return 0, err
-	}
-	defer l.Close()
-	addr := strings.Split(l.Addr().String(), ":")
-	port, err := strconv.Atoi(addr[len(addr)-1])
-	if err != nil {
-		return 0, err
-	}
-	return port, nil
-}
-
 func TestAggregatedAPIServer(t *testing.T) {
 	stopCh := make(chan struct{})
 	defer close(stopCh)
@@ -106,7 +92,7 @@ func TestAggregatedAPIServer(t *testing.T) {
 	go func() {
 		for {
 			// always get a fresh port in case something claimed the old one
-			kubePort, err := localPort()
+			kubePort, err := framework.FindFreeLocalPort()
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -179,7 +165,7 @@ func TestAggregatedAPIServer(t *testing.T) {
 	go func() {
 		for {
 			// always get a fresh port in case something claimed the old one
-			wardlePortInt, err := localPort()
+			wardlePortInt, err := framework.FindFreeLocalPort()
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -256,7 +242,7 @@ func TestAggregatedAPIServer(t *testing.T) {
 	go func() {
 		for {
 			// always get a fresh port in case something claimed the old one
-			aggregatorPortInt, err := localPort()
+			aggregatorPortInt, err := framework.FindFreeLocalPort()
 			if err != nil {
 				t.Fatal(err)
 			}

test/integration/federation/BUILD

@@ -9,16 +9,15 @@ load(
 
 go_test(
     name = "go_default_test",
-    srcs = ["server_test.go"],
+    srcs = ["api_test.go"],
     tags = ["automanaged"],
     deps = [
         "//federation/apis/federation/v1beta1:go_default_library",
-        "//federation/cmd/federation-apiserver/app:go_default_library",
-        "//federation/cmd/federation-apiserver/app/options:go_default_library",
         "//pkg/api/v1:go_default_library",
         "//pkg/apis/autoscaling/v1:go_default_library",
         "//pkg/apis/batch/v1:go_default_library",
         "//pkg/apis/extensions/v1beta1:go_default_library",
+        "//test/integration/federation/framework:go_default_library",
         "//vendor:github.com/stretchr/testify/assert",
         "//vendor:k8s.io/apimachinery/pkg/apis/meta/v1",
         "//vendor:k8s.io/apimachinery/pkg/runtime/schema",
@@ -34,6 +33,9 @@ filegroup(
 
 filegroup(
     name = "all-srcs",
-    srcs = [":package-srcs"],
+    srcs = [
+        ":package-srcs",
+        "//test/integration/federation/framework:all-srcs",
+    ],
     tags = ["automanaged"],
 )

test/integration/federation/api_test.go

@@ -14,33 +14,27 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package app
+package federation
 
 import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
-	"os"
 	"testing"
-	"time"
 
 	"github.com/stretchr/testify/assert"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	fed_v1b1 "k8s.io/kubernetes/federation/apis/federation/v1beta1"
-	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app"
-	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app/options"
 	"k8s.io/kubernetes/pkg/api/v1"
 	autoscaling_v1 "k8s.io/kubernetes/pkg/apis/autoscaling/v1"
 	batch_v1 "k8s.io/kubernetes/pkg/apis/batch/v1"
 	ext_v1b1 "k8s.io/kubernetes/pkg/apis/extensions/v1beta1"
+	"k8s.io/kubernetes/test/integration/federation/framework"
 )
 
-var securePort = 6443 + 2
-var insecurePort = 8080 + 2
-var serverIP = fmt.Sprintf("http://localhost:%v", insecurePort)
 var groupVersions = []schema.GroupVersion{
 	fed_v1b1.SchemeGroupVersion,
 	ext_v1b1.SchemeGroupVersion,
@@ -48,42 +42,25 @@ var groupVersions = []schema.GroupVersion{
 	//	autoscaling_v1.SchemeGroupVersion,
 }
 
-func TestRun(t *testing.T) {
-	certDir, err := ioutil.TempDir("", "")
-	if err != nil {
-		t.Fatalf("Failed to create temporary certificate directory: %v", err)
-	}
-	defer os.RemoveAll(certDir)
+type apiTestFunc func(t *testing.T, host string)
 
-	s := options.NewServerRunOptions()
-	s.SecureServing.ServingOptions.BindPort = securePort
-	s.InsecureServing.BindPort = insecurePort
-	s.Etcd.StorageConfig.ServerList = []string{"http://localhost:2379"}
-	s.SecureServing.ServerCert.CertDirectory = certDir
+func TestFederationAPI(t *testing.T) {
+	f := &framework.FederationAPIFixture{}
+	f.Setup(t)
+	defer f.Teardown(t)
 
-	go func() {
-		if err := app.Run(s); err != nil {
-			t.Fatalf("Error in bringing up the server: %v", err)
-		}
-	}()
-	if err := waitForApiserverUp(); err != nil {
-		t.Fatalf("%v", err)
+	testCases := map[string]apiTestFunc{
+		"swaggerSpec":     testSwaggerSpec,
+		"support":         testSupport,
+		"apiGroupList":    testAPIGroupList,
+		"apiGroup":        testAPIGroup,
+		"apiResourceList": testAPIResourceList,
 	}
-	testSwaggerSpec(t)
-	testSupport(t)
-	testAPIGroupList(t)
-	testAPIGroup(t)
-	testAPIResourceList(t)
-}
-
-func waitForApiserverUp() error {
-	for start := time.Now(); time.Since(start) < time.Minute; time.Sleep(5 * time.Second) {
-		_, err := http.Get(serverIP)
-		if err == nil {
-			return nil
-		}
+	for testName, testFunc := range testCases {
+		t.Run(testName, func(t *testing.T) {
+			testFunc(t, f.Host)
+		})
 	}
-	return fmt.Errorf("waiting for apiserver timed out")
 }
 
 func readResponse(serverURL string) ([]byte, error) {
@@ -102,16 +79,16 @@ func readResponse(serverURL string) ([]byte, error) {
 	return contents, nil
 }
 
-func testSwaggerSpec(t *testing.T) {
-	serverURL := serverIP + "/swaggerapi"
+func testSwaggerSpec(t *testing.T, host string) {
+	serverURL := host + "/swaggerapi"
 	_, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
 	}
 }
 
-func testSupport(t *testing.T) {
-	serverURL := serverIP + "/version"
+func testSupport(t *testing.T, host string) {
+	serverURL := host + "/version"
 	_, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -127,7 +104,7 @@ func findGroup(groups []metav1.APIGroup, groupName string) *metav1.APIGroup {
 	return nil
 }
 
-func testAPIGroupList(t *testing.T) {
+func testAPIGroupList(t *testing.T, host string) {
 	groupVersionForDiscoveryMap := make(map[string]metav1.GroupVersionForDiscovery)
 	for _, groupVersion := range groupVersions {
 		groupVersionForDiscoveryMap[groupVersion.Group] = metav1.GroupVersionForDiscovery{
@@ -136,7 +113,7 @@ func testAPIGroupList(t *testing.T) {
 		}
 	}
 
-	serverURL := serverIP + "/apis"
+	serverURL := host + "/apis"
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -158,9 +135,9 @@ func testAPIGroupList(t *testing.T) {
 	}
 }
 
-func testAPIGroup(t *testing.T) {
+func testAPIGroup(t *testing.T, host string) {
 	for _, groupVersion := range groupVersions {
-		serverURL := serverIP + "/apis/" + groupVersion.Group
+		serverURL := host + "/apis/" + groupVersion.Group
 		contents, err := readResponse(serverURL)
 		if err != nil {
 			t.Fatalf("%v", err)
@@ -183,11 +160,11 @@ func testAPIGroup(t *testing.T) {
 		assert.Equal(t, apiGroup.PreferredVersion, apiGroup.Versions[0])
 	}
 
-	testCoreAPIGroup(t)
+	testCoreAPIGroup(t, host)
 }
 
-func testCoreAPIGroup(t *testing.T) {
-	serverURL := serverIP + "/api"
+func testCoreAPIGroup(t *testing.T, host string) {
+	serverURL := host + "/api"
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -211,16 +188,16 @@ func findResource(resources []metav1.APIResource, resourceName string) *metav1.A
 	return nil
 }
 
-func testAPIResourceList(t *testing.T) {
-	testFederationResourceList(t)
-	testCoreResourceList(t)
-	testExtensionsResourceList(t)
-	//	testBatchResourceList(t)
-	//	testAutoscalingResourceList(t)
+func testAPIResourceList(t *testing.T, host string) {
+	testFederationResourceList(t, host)
+	testCoreResourceList(t, host)
+	testExtensionsResourceList(t, host)
+	// testBatchResourceList(t, host)
+	// testAutoscalingResourceList(t, host)
 }
 
-func testFederationResourceList(t *testing.T) {
-	serverURL := serverIP + "/apis/" + fed_v1b1.SchemeGroupVersion.String()
+func testFederationResourceList(t *testing.T, host string) {
+	serverURL := host + "/apis/" + fed_v1b1.SchemeGroupVersion.String()
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -243,8 +220,8 @@ func testFederationResourceList(t *testing.T) {
 	assert.False(t, found.Namespaced)
 }
 
-func testCoreResourceList(t *testing.T) {
-	serverURL := serverIP + "/api/" + v1.SchemeGroupVersion.String()
+func testCoreResourceList(t *testing.T, host string) {
+	serverURL := host + "/api/" + v1.SchemeGroupVersion.String()
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -294,8 +271,8 @@ func testCoreResourceList(t *testing.T) {
 	assert.True(t, found.Namespaced)
 }
 
-func testExtensionsResourceList(t *testing.T) {
-	serverURL := serverIP + "/apis/" + ext_v1b1.SchemeGroupVersion.String()
+func testExtensionsResourceList(t *testing.T, host string) {
+	serverURL := host + "/apis/" + ext_v1b1.SchemeGroupVersion.String()
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -351,8 +328,8 @@ func testExtensionsResourceList(t *testing.T) {
 	found = findResource(apiResourceList.APIResources, "deployments/rollback")
 }
 
-func testBatchResourceList(t *testing.T) {
-	serverURL := serverIP + "/apis/" + batch_v1.SchemeGroupVersion.String()
+func testBatchResourceList(t *testing.T, host string) {
+	serverURL := host + "/apis/" + batch_v1.SchemeGroupVersion.String()
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)
@@ -377,8 +354,8 @@ func testBatchResourceList(t *testing.T) {
 	assert.True(t, found.Namespaced)
 }
 
-func testAutoscalingResourceList(t *testing.T) {
-	serverURL := serverIP + "/apis/" + autoscaling_v1.SchemeGroupVersion.String()
+func testAutoscalingResourceList(t *testing.T, host string) {
+	serverURL := host + "/apis/" + autoscaling_v1.SchemeGroupVersion.String()
 	contents, err := readResponse(serverURL)
 	if err != nil {
 		t.Fatalf("%v", err)

test/integration/federation/framework/BUILD

@@ -0,0 +1,37 @@
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "api.go",
+        "util.go",
+    ],
+    tags = ["automanaged"],
+    deps = [
+        "//federation/cmd/federation-apiserver/app:go_default_library",
+        "//federation/cmd/federation-apiserver/app/options:go_default_library",
+        "//test/integration/framework:go_default_library",
+        "//vendor:github.com/pborman/uuid",
+        "//vendor:k8s.io/apimachinery/pkg/util/wait",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

test/integration/federation/framework/api.go

@@ -0,0 +1,120 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package framework
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/pborman/uuid"
+
+	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app"
+	"k8s.io/kubernetes/federation/cmd/federation-apiserver/app/options"
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+const (
+	apiNoun      = "federation apiserver"
+	waitInterval = 50 * time.Millisecond
+)
+
+func getRunOptions() *options.ServerRunOptions {
+	r := options.NewServerRunOptions()
+	r.Etcd.StorageConfig.ServerList = []string{framework.GetEtcdURLFromEnv()}
+	// Use a unique prefix to ensure isolation from other tests using the same etcd instance
+	r.Etcd.StorageConfig.Prefix = uuid.New()
+	// Disable secure serving
+	r.SecureServing.ServingOptions.BindPort = 0
+	return r
+}
+
+// FederationAPIFixture manages a federation api server
+type FederationAPIFixture struct {
+	Host     string
+	stopChan chan struct{}
+}
+
+func (f *FederationAPIFixture) Setup(t *testing.T) {
+	if f.stopChan != nil {
+		t.Fatal("Setup() already called")
+	}
+	defer TeardownOnPanic(t, f)
+
+	f.stopChan = make(chan struct{})
+
+	runOptions := getRunOptions()
+
+	err := startServer(t, runOptions, f.stopChan)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	f.Host = fmt.Sprintf("http://%s:%d", runOptions.InsecureServing.BindAddress, runOptions.InsecureServing.BindPort)
+
+	err = waitForServer(t, f.Host)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
+
+func (f *FederationAPIFixture) Teardown(t *testing.T) {
+	if f.stopChan != nil {
+		close(f.stopChan)
+		f.stopChan = nil
+	}
+}
+
+func startServer(t *testing.T, runOptions *options.ServerRunOptions, stopChan <-chan struct{}) error {
+	err := wait.PollImmediate(waitInterval, wait.ForeverTestTimeout, func() (bool, error) {
+		port, err := framework.FindFreeLocalPort()
+		if err != nil {
+			t.Logf("Error allocating an ephemeral port: %v", err)
+			return false, nil
+		}
+
+		runOptions.InsecureServing.BindPort = port
+
+		err = app.NonBlockingRun(runOptions, stopChan)
+		if err != nil {
+			t.Logf("Error starting the %s: %v", apiNoun, err)
+			return false, nil
+		}
+		return true, nil
+	})
+	if err != nil {
+		return fmt.Errorf("Timed out waiting for the %s: %v", apiNoun, err)
+	}
+	return nil
+}
+
+func waitForServer(t *testing.T, host string) error {
+	err := wait.PollImmediate(waitInterval, wait.ForeverTestTimeout, func() (bool, error) {
+		_, err := http.Get(host)
+		if err != nil {
+			t.Logf("Error when trying to contact the API: %v", err)
+			return false, nil
+		}
+		return true, nil
+	})
+	if err != nil {
+		return fmt.Errorf("Timed out waiting for the %s: %v", apiNoun, err)
+	}
+	return nil
+}

test/integration/federation/framework/util.go

@@ -0,0 +1,35 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package framework
+
+import (
+	"testing"
+)
+
+// Setup is likely to be fixture-specific, but Teardown needs to be
+// consistent to enable TeardownOnPanic.
+type TestFixture interface {
+	Teardown(t *testing.T)
+}
+
+// TeardownOnPanic can be used to ensure cleanup on setup failure.
+func TeardownOnPanic(t *testing.T, f TestFixture) {
+	if r := recover(); r != nil {
+		f.Teardown(t)
+		panic(r)
+	}
+}

test/integration/framework/master_utils.go

@@ -22,6 +22,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	goruntime "runtime"
+	"strconv"
 	"sync"
 	"testing"
 	"time"
@@ -509,3 +510,25 @@ func RunParallel(task Task, numTasks, numWorkers int) {
 	wg.Wait()
 	close(semCh)
 }
+
+// FindFreeLocalPort returns the number of an available port number on
+// the loopback interface.  Useful for determining the port to launch
+// a server on.  Error handling required - there is a non-zero chance
+// that the returned port number will be bound by another process
+// after this function returns.
+func FindFreeLocalPort() (int, error) {
+	l, err := net.Listen("tcp", ":0")
+	if err != nil {
+		return 0, err
+	}
+	defer l.Close()
+	_, portStr, err := net.SplitHostPort(l.Addr().String())
+	if err != nil {
+		return 0, err
+	}
+	port, err := strconv.Atoi(portStr)
+	if err != nil {
+		return 0, err
+	}
+	return port, nil
+}