Merge pull request #14034 from jszczepkowski/hpa-unittest

Unittests for horizontal pod autoscaler controller.

pkg/client/unversioned/testclient/fake_services.go

@@ -77,6 +77,5 @@ func (c *FakeServices) Watch(label labels.Selector, field fields.Selector, resou
 }
 
 func (c *FakeServices) ProxyGet(name, path string, params map[string]string) unversioned.ResponseWrapper {
-	c.Fake.Invokes(NewProxyGetAction("services", c.Namespace, name, path, params), nil)
+	return c.Fake.InvokesProxy(NewProxyGetAction("services", c.Namespace, name, path, params))
-	return nil
 }

pkg/client/unversioned/testclient/fixture.go

@@ -25,6 +25,7 @@ import (
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/errors"
 	"k8s.io/kubernetes/pkg/api/meta"
+	client "k8s.io/kubernetes/pkg/client/unversioned"
 	"k8s.io/kubernetes/pkg/runtime"
 	"k8s.io/kubernetes/pkg/util/yaml"
 	"k8s.io/kubernetes/pkg/watch"
@@ -260,7 +261,7 @@ func (r *SimpleReactor) React(action Action) (bool, runtime.Object, error) {
 	return r.Reaction(action)
 }
 
-// SimpleWatchReactor is a Reactor.  Each reaction function is attached to a given verb,resource tuple.  "*" in either field matches everything for that value.
+// SimpleWatchReactor is a WatchReactor.  Each reaction function is attached to a given resource.  "*" matches everything for that value.
 // For instance, *,pods matches all verbs on pods.  This allows for easier composition of reaction functions
 type SimpleWatchReactor struct {
 	Resource string
@@ -280,3 +281,24 @@ func (r *SimpleWatchReactor) Handles(action Action) bool {
 func (r *SimpleWatchReactor) React(action Action) (bool, watch.Interface, error) {
 	return r.Reaction(action)
 }
+
+// SimpleProxyReactor is a ProxyReactor.  Each reaction function is attached to a given resource.  "*" matches everything for that value.
+// For instance, *,pods matches all verbs on pods.  This allows for easier composition of reaction functions.
+type SimpleProxyReactor struct {
+	Resource string
+
+	Reaction ProxyReactionFunc
+}
+
+func (r *SimpleProxyReactor) Handles(action Action) bool {
+	resourceCovers := r.Resource == "*" || r.Resource == action.GetResource()
+	if !resourceCovers {
+		return false
+	}
+
+	return true
+}
+
+func (r *SimpleProxyReactor) React(action Action) (bool, client.ResponseWrapper, error) {
+	return r.Reaction(action)
+}

pkg/client/unversioned/testclient/testclient.go

@@ -54,6 +54,8 @@ type Fake struct {
 	ReactionChain []Reactor
 	// WatchReactionChain is the list of watch reactors that will be attempted for every request in the order they are tried
 	WatchReactionChain []WatchReactor
+	// ProxyReactionChain is the list of proxy reactors that will be attempted for every request in the order they are tried
+	ProxyReactionChain []ProxyReactor
 }
 
 // Reactor is an interface to allow the composition of reaction functions.
@@ -72,6 +74,14 @@ type WatchReactor interface {
 	React(action Action) (handled bool, ret watch.Interface, err error)
 }
 
+// ProxyReactor is an interface to allow the composition of proxy get functions.
+type ProxyReactor interface {
+	// Handles indicates whether or not this Reactor deals with a given action
+	Handles(action Action) bool
+	// React handles a watch action and returns results.  It may choose to delegate by indicated handled=false
+	React(action Action) (handled bool, ret client.ResponseWrapper, err error)
+}
+
 // ReactionFunc is a function that returns an object or error for a given Action.  If "handled" is false,
 // then the test client will continue ignore the results and continue to the next ReactionFunc
 type ReactionFunc func(action Action) (handled bool, ret runtime.Object, err error)
@@ -80,6 +90,10 @@ type ReactionFunc func(action Action) (handled bool, ret runtime.Object, err err
 // then the test client will continue ignore the results and continue to the next ReactionFunc
 type WatchReactionFunc func(action Action) (handled bool, ret watch.Interface, err error)
 
+// ProxyReactionFunc is a function that returns a ResponseWrapper interface for a given Action.  If "handled" is false,
+// then the test client will continue ignore the results and continue to the next ProxyReactionFunc
+type ProxyReactionFunc func(action Action) (handled bool, ret client.ResponseWrapper, err error)
+
 // AddReactor appends a reactor to the end of the chain
 func (c *Fake) AddReactor(verb, resource string, reaction ReactionFunc) {
 	c.ReactionChain = append(c.ReactionChain, &SimpleReactor{verb, resource, reaction})
@@ -97,6 +111,11 @@ func (c *Fake) AddWatchReactor(resource string, reaction WatchReactionFunc) {
 	c.WatchReactionChain = append(c.WatchReactionChain, &SimpleWatchReactor{resource, reaction})
 }
 
+// AddProxyReactor appends a reactor to the end of the chain
+func (c *Fake) AddProxyReactor(resource string, reaction ProxyReactionFunc) {
+	c.ProxyReactionChain = append(c.ProxyReactionChain, &SimpleProxyReactor{resource, reaction})
+}
+
 // Invokes records the provided Action and then invokes the ReactFn (if provided).
 // defaultReturnObj is expected to be of the same type a normal call would return.
 func (c *Fake) Invokes(action Action, defaultReturnObj runtime.Object) (runtime.Object, error) {
@@ -142,6 +161,28 @@ func (c *Fake) InvokesWatch(action Action) (watch.Interface, error) {
 	return nil, fmt.Errorf("unhandled watch: %#v", action)
 }
 
+// InvokesProxy records the provided Action and then invokes the ReactFn (if provided).
+func (c *Fake) InvokesProxy(action Action) client.ResponseWrapper {
+	c.Lock()
+	defer c.Unlock()
+
+	c.actions = append(c.actions, action)
+	for _, reactor := range c.ProxyReactionChain {
+		if !reactor.Handles(action) {
+			continue
+		}
+
+		handled, ret, err := reactor.React(action)
+		if !handled || err != nil {
+			continue
+		}
+
+		return ret
+	}
+
+	return nil
+}
+
 // ClearActions clears the history of actions called on the fake client
 func (c *Fake) ClearActions() {
 	c.Lock()

pkg/controller/podautoscaler/horizontal.go

@@ -79,8 +79,9 @@ func (a *HorizontalController) reconcileAutoscaler(hpa experimental.HorizontalPo
 		return fmt.Errorf("failed to query scale subresource for %s: %v", reference, err)
 	}
 	currentReplicas := scale.Status.Replicas
-	currentConsumption, err := a.metricsClient.ResourceConsumption(hpa.Spec.ScaleRef.Namespace).Get(hpa.Spec.Target.Resource,
+	currentConsumption, err := a.metricsClient.
-		scale.Status.Selector)
+		ResourceConsumption(hpa.Spec.ScaleRef.Namespace).
+		Get(hpa.Spec.Target.Resource, scale.Status.Selector)
 
 	// TODO: what to do on partial errors (like metrics obtained for 75% of pods).
 	if err != nil {

pkg/controller/podautoscaler/horizontal_test.go

@@ -17,195 +17,345 @@ limitations under the License.
 package podautoscaler
 
 import (
+	"encoding/json"
 	"fmt"
-	"net/http"
+	"io"
-	"net/http/httptest"
 	"testing"
+	"time"
 
 	"k8s.io/kubernetes/pkg/api"
 	_ "k8s.io/kubernetes/pkg/api/latest"
 	"k8s.io/kubernetes/pkg/api/resource"
-	"k8s.io/kubernetes/pkg/api/testapi"
 	"k8s.io/kubernetes/pkg/apis/experimental"
 	client "k8s.io/kubernetes/pkg/client/unversioned"
+	"k8s.io/kubernetes/pkg/client/unversioned/testclient"
 	"k8s.io/kubernetes/pkg/controller/podautoscaler/metrics"
 	"k8s.io/kubernetes/pkg/runtime"
-	"k8s.io/kubernetes/pkg/util"
 
-	"github.com/golang/glog"
+	heapster "k8s.io/heapster/api/v1/types"
+
 	"github.com/stretchr/testify/assert"
 )
 
-const (
+func (w fakeResponseWrapper) DoRaw() ([]byte, error) {
-	namespace    = api.NamespaceDefault
+	return w.raw, nil
-	rcName       = "app-rc"
-	podNameLabel = "app"
-	hpaName      = "foo"
-
-	hpaListHandler   = "HpaList"
-	scaleHandler     = "Scale"
-	updateHpaHandler = "HpaUpdate"
-	eventHandler     = "Event"
-)
-
-type serverResponse struct {
-	statusCode int
-	obj        interface{}
 }
 
-type fakeMetricsClient struct {
+func (w fakeResponseWrapper) Stream() (io.ReadCloser, error) {
-	consumption metrics.ResourceConsumptionClient
+	return nil, nil
 }
 
-type fakeResourceConsumptionClient struct {
+func newFakeResponseWrapper(raw []byte) fakeResponseWrapper {
-	metrics map[api.ResourceName]experimental.ResourceConsumption
+	return fakeResponseWrapper{raw: raw}
 }
 
-func (f *fakeMetricsClient) ResourceConsumption(namespace string) metrics.ResourceConsumptionClient {
+type fakeResponseWrapper struct {
-	return f.consumption
+	raw []byte
 }
 
-func (f *fakeResourceConsumptionClient) Get(resource api.ResourceName, selector map[string]string) (*experimental.ResourceConsumption, error) {
+type testCase struct {
-	consumption, found := f.metrics[resource]
+	minCount        int
-	if !found {
+	maxCount        int
-		return nil, fmt.Errorf("resource not found: %v", resource)
+	initialReplicas int
-	}
+	desiredReplicas int
-	return &consumption, nil
+	targetResource  api.ResourceName
+	targetLevel     resource.Quantity
+	reportedLevels  []uint64
+	scaleUpdated    bool
+	eventCreated    bool
+	verifyEvents    bool
 }
 
-func makeTestServer(t *testing.T, responses map[string]*serverResponse) (*httptest.Server, map[string]*util.FakeHandler) {
+func (tc *testCase) prepareTestClient(t *testing.T) *testclient.Fake {
+	namespace := "test-namespace"
+	hpaName := "test-hpa"
+	rcName := "test-rc"
+	podNamePrefix := "test-pod"
 
-	handlers := map[string]*util.FakeHandler{}
+	tc.scaleUpdated = false
-	mux := http.NewServeMux()
+	tc.eventCreated = false
 
-	mkHandler := func(url string, response serverResponse) *util.FakeHandler {
+	fakeClient := &testclient.Fake{}
-		handler := util.FakeHandler{
+	fakeClient.AddReactor("list", "horizontalpodautoscalers", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
-			StatusCode:   response.statusCode,
+		obj := &experimental.HorizontalPodAutoscalerList{
-			ResponseBody: runtime.EncodeOrDie(testapi.Experimental.Codec(), response.obj.(runtime.Object)),
+			Items: []experimental.HorizontalPodAutoscaler{
-		}
+				{
-		mux.Handle(url, &handler)
+					ObjectMeta: api.ObjectMeta{
-		glog.Infof("Will handle %s", url)
+						Name:      hpaName,
-		return &handler
+						Namespace: namespace,
-	}
+						SelfLink:  "experimental/v1/namespaces/" + namespace + "/horizontalpodautoscalers/" + hpaName,
-
+					},
-	if responses[hpaListHandler] != nil {
+					Spec: experimental.HorizontalPodAutoscalerSpec{
-		handlers[hpaListHandler] = mkHandler("/apis/experimental/v1/horizontalpodautoscalers", *responses[hpaListHandler])
+						ScaleRef: &experimental.SubresourceReference{
-	}
+							Kind:        "replicationController",
-
+							Name:        rcName,
-	if responses[scaleHandler] != nil {
+							Namespace:   namespace,
-		handlers[scaleHandler] = mkHandler(
+							Subresource: "scale",
-			fmt.Sprintf("/apis/experimental/v1/namespaces/%s/replicationcontrollers/%s/scale", namespace, rcName), *responses[scaleHandler])
+						},
-	}
+						MinCount: tc.minCount,
-
+						MaxCount: tc.maxCount,
-	if responses[updateHpaHandler] != nil {
+						Target:   experimental.ResourceConsumption{Resource: tc.targetResource, Quantity: tc.targetLevel},
-		handlers[updateHpaHandler] = mkHandler(fmt.Sprintf("/apis/experimental/v1/namespaces/%s/horizontalpodautoscalers/%s", namespace, hpaName),
-			*responses[updateHpaHandler])
-	}
-
-	if responses[eventHandler] != nil {
-		handlers[eventHandler] = mkHandler(fmt.Sprintf("/api/v1/namespaces/%s/events", namespace),
-			*responses[eventHandler])
-	}
-
-	mux.HandleFunc("/", func(res http.ResponseWriter, req *http.Request) {
-		t.Errorf("unexpected request: %v", req.RequestURI)
-		res.WriteHeader(http.StatusNotFound)
-	})
-	return httptest.NewServer(mux), handlers
-}
-
-func TestSyncEndpointsItemsPreserveNoSelector(t *testing.T) {
-	hpaResponse := serverResponse{http.StatusOK, &experimental.HorizontalPodAutoscalerList{
-		Items: []experimental.HorizontalPodAutoscaler{
-			{
-				ObjectMeta: api.ObjectMeta{
-					Name:      hpaName,
-					Namespace: namespace,
-					SelfLink:  "/apis/experimental/v1/namespaces/" + namespace + "/horizontalpodautoscalers/" + hpaName,
-				},
-				Spec: experimental.HorizontalPodAutoscalerSpec{
-					ScaleRef: &experimental.SubresourceReference{
-						Kind:        "replicationController",
-						Name:        rcName,
-						Namespace:   namespace,
-						Subresource: "scale",
 					},
-					MinCount: 1,
-					MaxCount: 5,
-					Target:   experimental.ResourceConsumption{Resource: api.ResourceCPU, Quantity: resource.MustParse("0.3")},
 				},
-			}}}}
-
-	scaleResponse := serverResponse{http.StatusOK, &experimental.Scale{
-		ObjectMeta: api.ObjectMeta{
-			Name:      rcName,
-			Namespace: namespace,
-		},
-		Spec: experimental.ScaleSpec{
-			Replicas: 1,
-		},
-		Status: experimental.ScaleStatus{
-			Replicas: 1,
-			Selector: map[string]string{"name": podNameLabel},
-		},
-	}}
-
-	status := experimental.HorizontalPodAutoscalerStatus{
-		CurrentReplicas: 1,
-		DesiredReplicas: 3,
-	}
-	updateHpaResponse := serverResponse{http.StatusOK, &experimental.HorizontalPodAutoscaler{
-		ObjectMeta: api.ObjectMeta{
-			Name:      hpaName,
-			Namespace: namespace,
-		},
-		Spec: experimental.HorizontalPodAutoscalerSpec{
-			ScaleRef: &experimental.SubresourceReference{
-				Kind:        "replicationController",
-				Name:        rcName,
-				Namespace:   namespace,
-				Subresource: "scale",
 			},
-			MinCount: 1,
+		}
-			MaxCount: 5,
+		return true, obj, nil
-			Target:   experimental.ResourceConsumption{Resource: api.ResourceCPU, Quantity: resource.MustParse("0.3")},
+	})
-		},
-		Status: &status,
-	}}
 
-	eventResponse := serverResponse{http.StatusOK, &api.Event{}}
+	fakeClient.AddReactor("get", "replicationController", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
+		obj := &experimental.Scale{
+			ObjectMeta: api.ObjectMeta{
+				Name:      rcName,
+				Namespace: namespace,
+			},
+			Spec: experimental.ScaleSpec{
+				Replicas: tc.initialReplicas,
+			},
+			Status: experimental.ScaleStatus{
+				Replicas: tc.initialReplicas,
+				Selector: map[string]string{"name": podNamePrefix},
+			},
+		}
+		return true, obj, nil
+	})
 
-	testServer, handlers := makeTestServer(t,
+	fakeClient.AddReactor("list", "pods", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
-		map[string]*serverResponse{
+		obj := &api.PodList{}
-			hpaListHandler:   &hpaResponse,
+		for i := 0; i < tc.initialReplicas; i++ {
-			scaleHandler:     &scaleResponse,
+			podName := fmt.Sprintf("%s-%d", podNamePrefix, i)
-			updateHpaHandler: &updateHpaResponse,
+			pod := api.Pod{
-			eventHandler:     &eventResponse,
+				Status: api.PodStatus{
-		})
+					Phase: api.PodRunning,
+				},
+				ObjectMeta: api.ObjectMeta{
+					Name:      podName,
+					Namespace: namespace,
+					Labels: map[string]string{
+						"name": podNamePrefix,
+					},
+				},
+			}
+			obj.Items = append(obj.Items, pod)
+		}
+		return true, obj, nil
+	})
 
-	defer testServer.Close()
+	fakeClient.AddProxyReactor("services", func(action testclient.Action) (handled bool, ret client.ResponseWrapper, err error) {
-	kubeClient := client.NewOrDie(&client.Config{Host: testServer.URL, Version: testapi.Experimental.Version()})
+		timestamp := time.Now()
-	fakeRC := fakeResourceConsumptionClient{metrics: map[api.ResourceName]experimental.ResourceConsumption{
+		metrics := heapster.MetricResultList{}
-		api.ResourceCPU: {Resource: api.ResourceCPU, Quantity: resource.MustParse("650m")},
+		for _, level := range tc.reportedLevels {
-	}}
+			metric := heapster.MetricResult{
-	fake := fakeMetricsClient{consumption: &fakeRC}
+				Metrics:         []heapster.MetricPoint{{timestamp, level}},
+				LatestTimestamp: timestamp,
+			}
+			metrics.Items = append(metrics.Items, metric)
+		}
+		heapsterRawMemResponse, _ := json.Marshal(&metrics)
+		return true, newFakeResponseWrapper(heapsterRawMemResponse), nil
+	})
 
-	hpaController := NewHorizontalController(kubeClient, &fake)
+	fakeClient.AddReactor("update", "replicationController", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
+		obj := action.(testclient.UpdateAction).GetObject().(*experimental.Scale)
+		replicas := action.(testclient.UpdateAction).GetObject().(*experimental.Scale).Spec.Replicas
+		assert.Equal(t, tc.desiredReplicas, replicas)
+		tc.scaleUpdated = true
+		return true, obj, nil
+	})
 
-	err := hpaController.reconcileAutoscalers()
+	fakeClient.AddReactor("update", "horizontalpodautoscalers", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
-	if err != nil {
+		obj := action.(testclient.UpdateAction).GetObject().(*experimental.HorizontalPodAutoscaler)
-		t.Fatal("Failed to reconcile: %v", err)
+		assert.Equal(t, namespace, obj.Namespace)
-	}
+		assert.Equal(t, hpaName, obj.Name)
-	for _, h := range handlers {
+		assert.Equal(t, tc.desiredReplicas, obj.Status.DesiredReplicas)
-		h.ValidateRequestCount(t, 1)
+		return true, obj, nil
-	}
+	})
-	obj, err := kubeClient.Codec.Decode([]byte(handlers[updateHpaHandler].RequestBody))
-	if err != nil {
-		t.Fatal("Failed to decode: %v %v", err)
-	}
-	hpa, _ := obj.(*experimental.HorizontalPodAutoscaler)
 
-	assert.Equal(t, 3, hpa.Status.DesiredReplicas)
+	fakeClient.AddReactor("*", "events", func(action testclient.Action) (handled bool, ret runtime.Object, err error) {
-	assert.Equal(t, int64(650), hpa.Status.CurrentConsumption.Quantity.MilliValue())
+		obj := action.(testclient.CreateAction).GetObject().(*api.Event)
-	assert.NotNil(t, hpa.Status.LastScaleTimestamp)
+		if tc.verifyEvents {
+			assert.Equal(t, "SuccessfulRescale", obj.Reason)
+			assert.Equal(t, fmt.Sprintf("New size: %d", tc.desiredReplicas), obj.Message)
+		}
+		tc.eventCreated = true
+		return true, obj, nil
+	})
+
+	return fakeClient
+}
+
+func (tc *testCase) verifyResults(t *testing.T) {
+	assert.Equal(t, tc.initialReplicas != tc.desiredReplicas, tc.scaleUpdated)
+	if tc.verifyEvents {
+		assert.Equal(t, tc.initialReplicas != tc.desiredReplicas, tc.eventCreated)
+	}
+}
+
+func (tc *testCase) runTest(t *testing.T) {
+	testClient := tc.prepareTestClient(t)
+	hpaController := NewHorizontalController(testClient, metrics.NewHeapsterMetricsClient(testClient))
+	err := hpaController.reconcileAutoscalers()
+	assert.Equal(t, nil, err)
+	if tc.verifyEvents {
+		// We need to wait for events to be broadcasted (sleep for longer than record.sleepDuration).
+		time.Sleep(12 * time.Second)
+	}
+	tc.verifyResults(t)
+}
+
+func TestCPU(t *testing.T) {
+	tc := testCase{
+		minCount:        1,
+		maxCount:        5,
+		initialReplicas: 1,
+		desiredReplicas: 2,
+		targetResource:  api.ResourceCPU,
+		targetLevel:     resource.MustParse("0.1"),
+		reportedLevels:  []uint64{200},
+	}
+	tc.runTest(t)
+}
+
+func TestMemory(t *testing.T) {
+	tc := testCase{
+		minCount:        1,
+		maxCount:        5,
+		initialReplicas: 1,
+		desiredReplicas: 2,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{2000},
+	}
+	tc.runTest(t)
+}
+
+func TestScaleUp(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        6,
+		initialReplicas: 3,
+		desiredReplicas: 5,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("3k"),
+		reportedLevels:  []uint64{3000, 5000, 7000},
+	}
+	tc.runTest(t)
+}
+
+func TestScaleDown(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        6,
+		initialReplicas: 5,
+		desiredReplicas: 3,
+		targetResource:  api.ResourceCPU,
+		targetLevel:     resource.MustParse("0.5"),
+		reportedLevels:  []uint64{100, 300, 500, 250, 250},
+	}
+	tc.runTest(t)
+}
+
+func TestTolerance(t *testing.T) {
+	tc := testCase{
+		minCount:        1,
+		maxCount:        5,
+		initialReplicas: 3,
+		desiredReplicas: 3,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{1010, 1030, 1020},
+	}
+	tc.runTest(t)
+}
+
+func TestMinCount(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        5,
+		initialReplicas: 3,
+		desiredReplicas: 2,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{10, 95, 10},
+	}
+	tc.runTest(t)
+}
+
+func TestMaxCount(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        5,
+		initialReplicas: 3,
+		desiredReplicas: 5,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{8000, 9500, 1000},
+	}
+	tc.runTest(t)
+}
+
+func TestSuperfluousMetrics(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        6,
+		initialReplicas: 4,
+		desiredReplicas: 4,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{4000, 9500, 3000, 7000, 3200, 2000},
+	}
+	tc.runTest(t)
+}
+
+func TestMissingMetrics(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        6,
+		initialReplicas: 4,
+		desiredReplicas: 4,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{400, 95},
+	}
+	tc.runTest(t)
+}
+
+func TestEmptyMetrics(t *testing.T) {
+	tc := testCase{
+		minCount:        2,
+		maxCount:        6,
+		initialReplicas: 4,
+		desiredReplicas: 4,
+		targetResource:  api.ResourceMemory,
+		targetLevel:     resource.MustParse("1k"),
+		reportedLevels:  []uint64{},
+	}
+	tc.runTest(t)
+}
+
+func TestEventCreated(t *testing.T) {
+	tc := testCase{
+		minCount:        1,
+		maxCount:        5,
+		initialReplicas: 1,
+		desiredReplicas: 2,
+		targetResource:  api.ResourceCPU,
+		targetLevel:     resource.MustParse("0.1"),
+		reportedLevels:  []uint64{200},
+		verifyEvents:    true,
+	}
+	tc.runTest(t)
+}
+
+func TestEventNotCreated(t *testing.T) {
+	tc := testCase{
+		minCount:        1,
+		maxCount:        5,
+		initialReplicas: 2,
+		desiredReplicas: 2,
+		targetResource:  api.ResourceCPU,
+		targetLevel:     resource.MustParse("0.2"),
+		reportedLevels:  []uint64{200, 200},
+		verifyEvents:    true,
+	}
+	tc.runTest(t)
 }