apiextensions: make conversion webhook test server more compositional

staging/src/k8s.io/apiextensions-apiserver/test/integration/conversion_test.go

@@ -22,6 +22,7 @@ import (
 	"net/http"
 	"reflect"
 	"strings"
+	"sync"
 	"testing"
 	"time"
 
@@ -36,6 +37,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/uuid"
+	"k8s.io/apimachinery/pkg/util/wait"
 	etcd3watcher "k8s.io/apiserver/pkg/storage/etcd3"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/dynamic"
@@ -131,7 +133,8 @@ func TestWebhookConverter(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.group, func(t *testing.T) {
-			tearDown, webhookClientConfig, webhookWaitReady, err := convert.StartConversionWebhookServerWithWaitReady(test.handler)
+			upCh, handler := closeOnCall(test.handler)
+			tearDown, webhookClientConfig, err := convert.StartConversionWebhookServer(handler)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -140,12 +143,17 @@ func TestWebhookConverter(t *testing.T) {
 			ctc.setConversionWebhook(t, webhookClientConfig)
 			defer ctc.removeConversionWebhook(t)
 
-			err = webhookWaitReady(30*time.Second, func() error {
-				// the marker's storage version is v1beta2, so a v1beta1 read always triggers conversion
+			// wait until new webhook is called the first time
+			if err := wait.PollImmediate(time.Millisecond*100, wait.ForeverTestTimeout, func() (bool, error) {
 				_, err := ctc.versionedClient(marker.GetNamespace(), "v1beta1").Get(marker.GetName(), metav1.GetOptions{})
-				return err
-			})
-			if err != nil {
+				select {
+				case <-upCh:
+					return true, nil
+				default:
+					t.Logf("Waiting for webhook to become effective, getting marker object: %v", err)
+					return false, nil
+				}
+			}); err != nil {
 				t.Fatal(err)
 			}
 
@@ -562,3 +570,14 @@ func newConversionMultiVersionFixture(namespace, name, version string) *unstruct
 		},
 	}
 }
+
+func closeOnCall(h http.Handler) (chan struct{}, http.Handler) {
+	ch := make(chan struct{})
+	once := sync.Once{}
+	return ch, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		once.Do(func() {
+			close(ch)
+		})
+		h.ServeHTTP(w, r)
+	})
+}

staging/src/k8s.io/apiextensions-apiserver/test/integration/convert/BUILD

@@ -10,7 +10,7 @@ go_library(
         "//staging/src/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//staging/src/k8s.io/apimachinery/pkg/runtime:go_default_library",
-        "//staging/src/k8s.io/apimachinery/pkg/util/uuid:go_default_library",
+        "//staging/src/k8s.io/apimachinery/pkg/util/wait:go_default_library",
     ],
 )
 

staging/src/k8s.io/apiextensions-apiserver/test/integration/convert/webhook.go

@@ -25,91 +25,51 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"strings"
-	"sync"
 	"testing"
 	"time"
 
+	"k8s.io/apimachinery/pkg/util/wait"
+
 	apiextensionsv1beta1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1beta1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/util/uuid"
 )
 
-// WaitReadyFunc calls triggerConversionFn periodically and waits until it detects that the webhook
-// conversion server has handled at least 1 conversion request or the timeout is exceeded, in which
-// case an error is returned.
-type WaitReadyFunc func(timeout time.Duration, triggerConversionFn func() error) error
-
-// StartConversionWebhookServerWithWaitReady starts an http server with the provided handler and returns the WebhookClientConfig
-// needed to configure a CRD to use this conversion webhook as its converter.
-// It also returns a WaitReadyFunc to be called after the CRD is configured to wait until the conversion webhook handler
-// accepts at least one conversion request. If the server fails to start, an error is returned.
-// WaitReady is useful when changing the conversion webhook config of an existing CRD because the update does not take effect immediately.
-func StartConversionWebhookServerWithWaitReady(handler http.Handler) (func(), *apiextensionsv1beta1.WebhookClientConfig, WaitReadyFunc, error) {
-	var once sync.Once
-	handlerReadyC := make(chan struct{})
-	readyNotifyHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		once.Do(func() {
-			close(handlerReadyC)
-		})
-		handler.ServeHTTP(w, r)
-	})
-
-	tearDown, webhookConfig, err := StartConversionWebhookServer(readyNotifyHandler)
-	if err != nil {
-		return nil, nil, nil, fmt.Errorf("error starting webhook server: %v", err)
-	}
-
-	waitReady := func(timeout time.Duration, triggerConversionFn func() error) error {
-		var err error
-		for {
-			select {
-			case <-handlerReadyC:
-				return nil
-			case <-time.After(timeout):
-				return fmt.Errorf("Timed out waiting for CRD webhook converter update, last trigger conversion error: %v", err)
-			case <-time.After(100 * time.Millisecond):
-				err = triggerConversionFn()
-			}
-		}
-	}
-	return tearDown, webhookConfig, waitReady, err
-}
-
 // StartConversionWebhookServer starts an http server with the provided handler and returns the WebhookClientConfig
 // needed to configure a CRD to use this conversion webhook as its converter.
 func StartConversionWebhookServer(handler http.Handler) (func(), *apiextensionsv1beta1.WebhookClientConfig, error) {
-	// Use a unique path for each webhook server. This ensures that all conversion requests
-	// received by the handler are intended for it; if a WebhookClientConfig other than this one
-	// is applied in the api server, conversion requests will not reach the handler (if they
-	// reach the server they will be returned at 404). This helps prevent tests that require a
-	// specific conversion webhook from accidentally using a different one, which could otherwise
-	// cause a test to flake or pass when it should fail. Since updating the conversion client
-	// config of a custom resource definition does not take effect immediately, this is needed
-	// by the WaitReady returned StartConversionWebhookServerWithWaitReady to detect when a
-	// conversion client config change in the api server has taken effect.
-	path := fmt.Sprintf("/conversionwebhook-%s", uuid.NewUUID())
 	roots := x509.NewCertPool()
 	if !roots.AppendCertsFromPEM(localhostCert) {
-		return nil, nil, fmt.Errorf("Failed to append Cert from PEM")
+		return nil, nil, fmt.Errorf("failed to append Cert from PEM")
 	}
 	cert, err := tls.X509KeyPair(localhostCert, localhostKey)
 	if err != nil {
-		return nil, nil, fmt.Errorf("Failed to build cert with error: %+v", err)
+		return nil, nil, fmt.Errorf("failed to build cert with error: %+v", err)
 	}
+
 	webhookMux := http.NewServeMux()
-	webhookMux.Handle(path, handler)
+	webhookMux.Handle("/convert", handler)
 	webhookServer := httptest.NewUnstartedServer(webhookMux)
 	webhookServer.TLS = &tls.Config{
 		RootCAs:      roots,
 		Certificates: []tls.Certificate{cert},
 	}
 	webhookServer.StartTLS()
-	endpoint := webhookServer.URL + path
+	endpoint := webhookServer.URL + "/convert"
 	webhookConfig := &apiextensionsv1beta1.WebhookClientConfig{
 		CABundle: localhostCert,
 		URL:      &endpoint,
 	}
+
+	// StartTLS returns immediately, there is a small chance of a race to avoid.
+	if err := wait.PollImmediate(time.Millisecond*100, wait.ForeverTestTimeout, func() (bool, error) {
+		_, err := webhookServer.Client().Get(webhookServer.URL) // even a 404 is fine
+		return err == nil, nil
+	}); err != nil {
+		webhookServer.Close()
+		return nil, nil, err
+	}
+
 	return webhookServer.Close, webhookConfig, nil
 }