Merge pull request #114237 from dgrisonnet/handle-series-error

Retry when recording an EventSerie results in an AlreadyExist error

staging/src/k8s.io/client-go/tools/events/event_broadcaster.go

@@ -248,6 +248,14 @@ func recordEvent(sink EventSink, event *eventsv1.Event) (*eventsv1.Event, bool)
 		return nil, false
 	case *errors.StatusError:
 		if errors.IsAlreadyExists(err) {
+			// If we tried to create an Event from an EventSerie, it means that
+			// the original Patch request failed because the Event we were
+			// trying to patch didn't exist. If the creation failed because the
+			// Event now exists, it is safe to retry.  This occurs when a new
+			// Event is emitted twice in a very short period of time.
+			if isEventSeries {
+				return nil, true
+			}
 			klog.V(5).Infof("Server rejected event '%#v': '%v' (will not retry!)", event, err)
 		} else {
 			klog.Errorf("Server rejected event '%#v': '%v' (will not retry!)", event, err)

staging/src/k8s.io/client-go/tools/events/event_broadcaster_test.go

@@ -0,0 +1,103 @@
+/*
+Copyright 2022 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 events
+
+import (
+	"context"
+	"reflect"
+	"testing"
+
+	eventsv1 "k8s.io/api/events/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/diff"
+	"k8s.io/client-go/kubernetes/fake"
+)
+
+func TestRecordEventToSink(t *testing.T) {
+	nonIsomorphicEvent := eventsv1.Event{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "test",
+			Namespace: metav1.NamespaceDefault,
+		},
+		Series: nil,
+	}
+
+	isomorphicEvent := *nonIsomorphicEvent.DeepCopy()
+	isomorphicEvent.Series = &eventsv1.EventSeries{Count: 2}
+
+	testCases := []struct {
+		name                  string
+		eventsToRecord        []eventsv1.Event
+		expectedRecordedEvent eventsv1.Event
+	}{
+		{
+			name: "record one Event",
+			eventsToRecord: []eventsv1.Event{
+				nonIsomorphicEvent,
+			},
+			expectedRecordedEvent: nonIsomorphicEvent,
+		},
+		{
+			name: "record one Event followed by an isomorphic one",
+			eventsToRecord: []eventsv1.Event{
+				nonIsomorphicEvent,
+				isomorphicEvent,
+			},
+			expectedRecordedEvent: isomorphicEvent,
+		},
+		{
+			name: "record one isomorphic Event before the original",
+			eventsToRecord: []eventsv1.Event{
+				isomorphicEvent,
+				nonIsomorphicEvent,
+			},
+			expectedRecordedEvent: isomorphicEvent,
+		},
+		{
+			name: "record one isomorphic Event without one already existing",
+			eventsToRecord: []eventsv1.Event{
+				isomorphicEvent,
+			},
+			expectedRecordedEvent: isomorphicEvent,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			kubeClient := fake.NewSimpleClientset()
+			eventSink := &EventSinkImpl{Interface: kubeClient.EventsV1()}
+
+			for _, ev := range tc.eventsToRecord {
+				recordEvent(eventSink, &ev)
+			}
+
+			recordedEvents, err := kubeClient.EventsV1().Events(metav1.NamespaceDefault).List(context.TODO(), metav1.ListOptions{})
+			if err != nil {
+				t.Errorf("expected to be able to list Events from fake client")
+			}
+
+			if len(recordedEvents.Items) != 1 {
+				t.Errorf("expected one Event to be recorded, found: %d", len(recordedEvents.Items))
+			}
+
+			recordedEvent := recordedEvents.Items[0]
+			if !reflect.DeepEqual(recordedEvent, tc.expectedRecordedEvent) {
+				t.Errorf("expected to have recorded Event: %#+v, got: %#+v\n diff: %s", tc.expectedRecordedEvent, recordedEvent, diff.ObjectReflectDiff(tc.expectedRecordedEvent, recordedEvent))
+			}
+		})
+	}
+}