Fix original object mutation on patch retry

test/integration/apiserver/patch_test.go

@@ -0,0 +1,116 @@
+// +build integration,!no-etcd
+
+/*
+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 apiserver
+
+import (
+	"fmt"
+	"sync"
+	"sync/atomic"
+	"testing"
+
+	"github.com/pborman/uuid"
+
+	"reflect"
+
+	"k8s.io/apimachinery/pkg/api/errors"
+	"k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apiserver/pkg/endpoints/handlers"
+	"k8s.io/kubernetes/pkg/api/v1"
+	"k8s.io/kubernetes/test/integration/framework"
+)
+
+// Tests that the apiserver retries non-overlapping conflicts on patches
+func TestPatchConflicts(t *testing.T) {
+	s, clientSet := setup(t)
+	defer s.Close()
+
+	ns := framework.CreateTestingNamespace("status-code", s, t)
+	defer framework.DeleteTestingNamespace(ns, s, t)
+
+	// Create the object we're going to conflict on
+	clientSet.Core().Secrets(ns.Name).Create(&v1.Secret{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: "test",
+			// Populate annotations so the strategic patch descends, compares, and notices the $patch directive
+			Annotations: map[string]string{"initial": "value"},
+		},
+	})
+	client := clientSet.Core().RESTClient()
+
+	successes := int32(0)
+
+	// Run a lot of simultaneous patch operations to exercise internal API server retry of patch application.
+	// Internally, a patch API call retries up to MaxRetryWhenPatchConflicts times if the resource version of the object has changed.
+	// If the resource version of the object changed between attempts, that means another one of our patch requests succeeded.
+	// That means if we run 2*MaxRetryWhenPatchConflicts patch attempts, we should see at least MaxRetryWhenPatchConflicts succeed.
+	wg := sync.WaitGroup{}
+	for i := 0; i < (2 * handlers.MaxRetryWhenPatchConflicts); i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			annotationName := fmt.Sprintf("annotation-%d", i)
+			labelName := fmt.Sprintf("label-%d", i)
+			value := uuid.NewRandom().String()
+
+			obj, err := client.Patch(types.StrategicMergePatchType).
+				Namespace(ns.Name).
+				Resource("secrets").
+				Name("test").
+				Body([]byte(fmt.Sprintf(`{"metadata":{"labels":{"%s":"%s"}, "annotations":{"$patch":"replace","%s":"%s"}}}`, labelName, value, annotationName, value))).
+				Do().
+				Get()
+
+			if errors.IsConflict(err) {
+				t.Logf("tolerated conflict error patching %s: %v", "secrets", err)
+				return
+			}
+			if err != nil {
+				t.Errorf("error patching %s: %v", "secrets", err)
+				return
+			}
+
+			accessor, err := meta.Accessor(obj)
+			if err != nil {
+				t.Errorf("error getting object from %s: %v", "secrets", err)
+				return
+			}
+			// make sure the label we wanted was effective
+			if accessor.GetLabels()[labelName] != value {
+				t.Errorf("patch of %s was ineffective, expected %s=%s, got labels %#v", "secrets", labelName, value, accessor.GetLabels())
+				return
+			}
+			// make sure the patch directive didn't get lost, and that the entire annotation map was replaced
+			if !reflect.DeepEqual(accessor.GetAnnotations(), map[string]string{annotationName: value}) {
+				t.Errorf("patch of %s with $patch directive was ineffective, didn't replace entire annotations map: %#v", "secrets", accessor.GetAnnotations())
+			}
+
+			atomic.AddInt32(&successes, 1)
+		}(i)
+	}
+	wg.Wait()
+
+	if successes < handlers.MaxRetryWhenPatchConflicts {
+		t.Errorf("Expected at least %d successful patches for %s, got %d", handlers.MaxRetryWhenPatchConflicts, "secrets", successes)
+	} else {
+		t.Logf("Got %d successful patches for %s", successes, "secrets")
+	}
+
+}