Adding events for system ooms.

Kubelet will continuously watch for system OOMs and generate events whenever it
encounters a system OOM.

pkg/kubelet/oom_watcher_test.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 kubelet
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/cadvisor"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+)
+
+type fakeEvent struct {
+	object    runtime.Object
+	timestamp util.Time
+	reason    string
+	message   string
+}
+
+type fakeRecorder struct {
+	events []fakeEvent
+}
+
+func (f fakeRecorder) Event(object runtime.Object, reason, message string) {
+	f.events = append(f.events, fakeEvent{object, util.Now(), reason, message})
+}
+
+func (f fakeRecorder) Eventf(object runtime.Object, reason, messageFmt string, args ...interface{}) {
+	f.events = append(f.events, fakeEvent{object, util.Now(), reason, fmt.Sprintf(messageFmt, args...)})
+}
+
+func (f fakeRecorder) PastEventf(object runtime.Object, timestamp util.Time, reason, messageFmt string, args ...interface{}) {
+	f.events = append(f.events, fakeEvent{object, timestamp, reason, fmt.Sprintf(messageFmt, args...)})
+}
+
+func TestBasic(t *testing.T) {
+	fakeRecorder := fakeRecorder{}
+	mockCadvisor := &cadvisor.Fake{}
+	node := &api.ObjectReference{}
+	oomWatcher := NewOOMWatcher(mockCadvisor, fakeRecorder)
+	go func() {
+		oomWatcher.RecordSysOOMs(node)
+	}()
+	// TODO: Improve this test once cadvisor exports events.EventChannel as an interface
+	// and thereby allow using a mock version of cadvisor.
+}