events: fix EventSeries starting count discrepancy

The kube-apiserver validation expects the Count of an EventSeries to be
at least 2, otherwise it rejects the Event. There was is discrepancy
between the client and the server since the client was iniatizing an
EventSeries to a count of 1.

According to the original KEP, the first event emitted should have an
EventSeries set to nil and the second isomorphic event should have an
EventSeries with a count of 2. Thus, we should matcht the behavior
define by the KEP and update the client.

Also, as an effort to make the old clients compatible with the servers,
we should allow Events with an EventSeries count of 1 to prevent any
unexpected rejections.

Signed-off-by: Damien Grisonnet <dgrisonn@redhat.com>

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

@@ -181,7 +181,7 @@ func (e *eventBroadcasterImpl) recordToSink(event *eventsv1.Event, clock clock.C
 					return nil
 				}
 				isomorphicEvent.Series = &eventsv1.EventSeries{
-					Count:            1,
+					Count:            2,
 					LastObservedTime: metav1.MicroTime{Time: clock.Now()},
 				}
 				return isomorphicEvent

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

@@ -106,7 +106,7 @@ func TestEventSeriesf(t *testing.T) {
 	nonIsomorphicEvent := expectedEvent.DeepCopy()
 	nonIsomorphicEvent.Action = "stopped"
 
-	expectedEvent.Series = &eventsv1.EventSeries{Count: 1}
+	expectedEvent.Series = &eventsv1.EventSeries{Count: 2}
 	table := []struct {
 		regarding    k8sruntime.Object
 		related      k8sruntime.Object

test/integration/events/events_test.go

@@ -18,6 +18,7 @@ package events
 
 import (
 	"context"
+	"fmt"
 	"testing"
 	"time"
 
@@ -96,3 +97,62 @@ func TestEventCompatibility(t *testing.T) {
 		t.Fatalf("unexpected err: %v", err)
 	}
 }
+
+func TestEventSeries(t *testing.T) {
+	result := kubeapiservertesting.StartTestServerOrDie(t, nil, []string{"--disable-admission-plugins", "ServiceAccount"}, framework.SharedEtcd())
+	defer result.TearDownFn()
+
+	client := clientset.NewForConfigOrDie(result.ClientConfig)
+
+	testPod := &v1.Pod{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "foo",
+			Namespace: "default",
+			UID:       "bar",
+		},
+	}
+
+	regarding, err := ref.GetReference(scheme.Scheme, testPod)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	related, err := ref.GetPartialReference(scheme.Scheme, testPod, ".spec.containers[0]")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	stopCh := make(chan struct{})
+	defer close(stopCh)
+
+	broadcaster := events.NewBroadcaster(&events.EventSinkImpl{Interface: client.EventsV1()})
+	defer broadcaster.Shutdown()
+	recorder := broadcaster.NewRecorder(scheme.Scheme, "k8s.io/kube-scheduler")
+	broadcaster.StartRecordingToSink(stopCh)
+	recorder.Eventf(regarding, related, v1.EventTypeNormal, "memoryPressure", "killed", "memory pressure")
+	recorder.Eventf(regarding, related, v1.EventTypeNormal, "memoryPressure", "killed", "memory pressure")
+	err = wait.PollImmediate(100*time.Millisecond, 20*time.Second, func() (done bool, err error) {
+		events, err := client.EventsV1().Events("").List(context.TODO(), metav1.ListOptions{})
+		if err != nil {
+			return false, err
+		}
+
+		if len(events.Items) != 1 {
+			return false, nil
+		}
+
+		if events.Items[0].Series == nil {
+			return false, nil
+		}
+
+		if events.Items[0].Series.Count != 2 {
+			return false, fmt.Errorf("expected EventSeries to have a starting count of 2, got: %d", events.Items[0].Series.Count)
+		}
+
+		return true, nil
+	})
+	if err != nil {
+		t.Fatalf("error waiting for an Event with a non nil Series to be created: %v", err)
+	}
+
+}