Add test for image in node status

pkg/kubelet/kubelet.go

@@ -3100,9 +3100,9 @@ func (kl *Kubelet) setNodeStatusImages(node *api.Node) {
 		glog.Errorf("Error getting image list: %v", err)
 	} else {
 		// sort the images from max to min, and only set top N images into the node status.
-		sort.Sort(ByImageSize(containerImages))
+		sort.Sort(byImageSize(containerImages))
 		if maxImagesInNodeStatus < len(containerImages) {
-			containerImages = containerImages[0 : maxImagesInNodeStatus-1]
+			containerImages = containerImages[0:maxImagesInNodeStatus]
 		}
 
 		for _, image := range containerImages {
@@ -3121,14 +3121,14 @@ func (kl *Kubelet) setNodeStatusGoRuntime(node *api.Node) {
 	node.Status.NodeInfo.Architecture = goRuntime.GOARCH
 }
 
-type ByImageSize []kubecontainer.Image
+type byImageSize []kubecontainer.Image
 
 // Sort from max to min
-func (a ByImageSize) Less(i, j int) bool {
+func (a byImageSize) Less(i, j int) bool {
 	return a[i].Size > a[j].Size
 }
-func (a ByImageSize) Len() int      { return len(a) }
-func (a ByImageSize) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
+func (a byImageSize) Len() int      { return len(a) }
+func (a byImageSize) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
 
 // Set status for the node.
 func (kl *Kubelet) setNodeStatusInfo(node *api.Node) {

pkg/kubelet/kubelet_test.go

@@ -26,6 +26,7 @@ import (
 	"os"
 	"reflect"
 	"sort"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -67,6 +68,7 @@ import (
 	"k8s.io/kubernetes/pkg/util/diff"
 	"k8s.io/kubernetes/pkg/util/flowcontrol"
 	"k8s.io/kubernetes/pkg/util/mount"
+	"k8s.io/kubernetes/pkg/util/rand"
 	utilruntime "k8s.io/kubernetes/pkg/util/runtime"
 	"k8s.io/kubernetes/pkg/util/sets"
 	"k8s.io/kubernetes/pkg/util/wait"
@@ -80,10 +82,19 @@ func init() {
 	utilruntime.ReallyCrash = true
 }
 
-const testKubeletHostname = "127.0.0.1"
+const (
+	testKubeletHostname = "127.0.0.1"
 
-const testReservationCPU = "200m"
-const testReservationMemory = "100M"
+	testReservationCPU    = "200m"
+	testReservationMemory = "100M"
+
+	maxImageTagsForTest = 3
+
+	// TODO(harry) any global place for these two?
+	// Reasonable size range of all container images. 90%ile of images on dockerhub drops into this range.
+	minImgSize int64 = 23 * 1024 * 1024
+	maxImgSize int64 = 1000 * 1024 * 1024
+)
 
 type fakeHTTP struct {
 	url string
@@ -105,11 +116,9 @@ type TestKubelet struct {
 	mounter          mount.Interface
 }
 
+// newTestKubelet returns test kubelet with two images.
 func newTestKubelet(t *testing.T) *TestKubelet {
-	fakeRuntime := &containertest.FakeRuntime{}
-	fakeRuntime.RuntimeType = "test"
-	fakeRuntime.VersionInfo = "1.5.0"
-	fakeRuntime.ImageList = []kubecontainer.Image{
+	imageList := []kubecontainer.Image{
 		{
 			ID:       "abc",
 			RepoTags: []string{"gcr.io/google_containers:v1", "gcr.io/google_containers:v2"},
@@ -121,6 +130,53 @@ func newTestKubelet(t *testing.T) *TestKubelet {
 			Size:     456,
 		},
 	}
+	return newTestKubeletWithImageList(t, imageList)
+}
+
+// generateTestingImageList generate randomly generated image list and corresponding expectedImageList.
+func generateTestingImageList(count int) ([]kubecontainer.Image, []api.ContainerImage) {
+	// imageList is randomly generated image list
+	var imageList []kubecontainer.Image
+	for ; count > 0; count-- {
+		imageItem := kubecontainer.Image{
+			ID:       string(util.NewUUID()),
+			RepoTags: generateImageTags(),
+			Size:     rand.Int63nRange(minImgSize, maxImgSize+1),
+		}
+		imageList = append(imageList, imageItem)
+	}
+
+	// expectedImageList is generated by imageList according to size and maxImagesInNodeStatus
+	// 1. sort the imageList by size
+	sort.Sort(byImageSize(imageList))
+	// 2. convert sorted imageList to api.ContainerImage list
+	var expectedImageList []api.ContainerImage
+	for _, kubeImage := range imageList {
+		apiImage := api.ContainerImage{
+			Names:     kubeImage.RepoTags,
+			SizeBytes: kubeImage.Size,
+		}
+
+		expectedImageList = append(expectedImageList, apiImage)
+	}
+	// 3. only returns the top maxImagesInNodeStatus images in expectedImageList
+	return imageList, expectedImageList[0:maxImagesInNodeStatus]
+}
+
+func generateImageTags() []string {
+	var tagList []string
+	count := rand.IntnRange(1, maxImageTagsForTest+1)
+	for ; count > 0; count-- {
+		tagList = append(tagList, "gcr.io/google_containers:v"+strconv.Itoa(count))
+	}
+	return tagList
+}
+
+func newTestKubeletWithImageList(t *testing.T, imageList []kubecontainer.Image) *TestKubelet {
+	fakeRuntime := &containertest.FakeRuntime{}
+	fakeRuntime.RuntimeType = "test"
+	fakeRuntime.VersionInfo = "1.5.0"
+	fakeRuntime.ImageList = imageList
 	fakeRecorder := &record.FakeRecorder{}
 	fakeKubeClient := &fake.Clientset{}
 	kubelet := &Kubelet{}
@@ -2349,7 +2405,9 @@ func updateDiskSpacePolicy(kubelet *Kubelet, mockCadvisor *cadvisortest.Mock, ro
 }
 
 func TestUpdateNewNodeStatus(t *testing.T) {
-	testKubelet := newTestKubelet(t)
+	// generate one more than maxImagesInNodeStatus in inputImageList
+	inputImageList, expectedImageList := generateTestingImageList(maxImagesInNodeStatus + 1)
+	testKubelet := newTestKubeletWithImageList(t, inputImageList)
 	kubelet := testKubelet.kubelet
 	kubeClient := testKubelet.fakeKubeClient
 	kubeClient.ReactionChain = fake.NewSimpleClientset(&api.NodeList{Items: []api.Node{
@@ -2434,16 +2492,7 @@ func TestUpdateNewNodeStatus(t *testing.T) {
 				{Type: api.NodeLegacyHostIP, Address: "127.0.0.1"},
 				{Type: api.NodeInternalIP, Address: "127.0.0.1"},
 			},
-			Images: []api.ContainerImage{
-				{
-					Names:     []string{"gcr.io/google_containers:v3", "gcr.io/google_containers:v4"},
-					SizeBytes: 456,
-				},
-				{
-					Names:     []string{"gcr.io/google_containers:v1", "gcr.io/google_containers:v2"},
-					SizeBytes: 123,
-				},
-			},
+			Images: expectedImageList,
 		},
 	}
 
@@ -2478,9 +2527,14 @@ func TestUpdateNewNodeStatus(t *testing.T) {
 		t.Errorf("unexpected node condition order. NodeReady should be last.")
 	}
 
-	if !api.Semantic.DeepEqual(expectedNode, updatedNode) {
-		t.Errorf("unexpected objects: %s", diff.ObjectDiff(expectedNode, updatedNode))
+	if maxImagesInNodeStatus != len(updatedNode.Status.Images) {
+		t.Errorf("unexpected image list length in node status, expected: %v, got: %v", maxImagesInNodeStatus, len(updatedNode.Status.Images))
+	} else {
+		if !api.Semantic.DeepEqual(expectedNode, updatedNode) {
+			t.Errorf("unexpected objects: %s", diff.ObjectDiff(expectedNode, updatedNode))
+		}
 	}
+
 }
 
 func TestUpdateNewNodeOutOfDiskStatusWithTransitionFrequency(t *testing.T) {

pkg/util/rand/rand.go

@@ -32,7 +32,7 @@ var rng = struct {
 	rand: rand.New(rand.NewSource(time.Now().UTC().UnixNano())),
 }
 
-// Intn generates an integer in range 0->max.
+// Intn generates an integer in range [0,max).
 // By design this should panic if input is invalid, <= 0.
 func Intn(max int) int {
 	rng.Lock()
@@ -40,6 +40,22 @@ func Intn(max int) int {
 	return rng.rand.Intn(max)
 }
 
+// IntnRange generates an integer in range [min,max).
+// By design this should panic if input is invalid, <= 0.
+func IntnRange(min, max int) int {
+	rng.Lock()
+	defer rng.Unlock()
+	return rng.rand.Intn(max-min) + min
+}
+
+// IntnRange generates an int64 integer in range [min,max).
+// By design this should panic if input is invalid, <= 0.
+func Int63nRange(min, max int64) int64 {
+	rng.Lock()
+	defer rng.Unlock()
+	return rng.rand.Int63n(max-min) + min
+}
+
 // Seed seeds the rng with the provided seed.
 func Seed(seed int64) {
 	rng.Lock()

pkg/util/rand/rand_test.go

@@ -24,6 +24,10 @@ import (
 	"testing"
 )
 
+const (
+	maxRangeTestCount = 500
+)
+
 func TestString(t *testing.T) {
 	valid := "0123456789abcdefghijklmnopqrstuvwxyz"
 	for _, l := range []int{0, 1, 2, 10, 123} {
@@ -84,3 +88,27 @@ func TestShuffle(t *testing.T) {
 		t.Errorf("Shuffle(%v) => %v, want %v", have, got, want)
 	}
 }
+
+func TestIntnRange(t *testing.T) {
+	// 0 is invalid.
+	for min, max := range map[int]int{1: 2, 10: 123, 100: 500} {
+		for i := 0; i < maxRangeTestCount; i++ {
+			inrange := IntnRange(min, max)
+			if inrange < min || inrange >= max {
+				t.Errorf("%v out of range (%v,%v)", inrange, min, max)
+			}
+		}
+	}
+}
+
+func TestInt63nRange(t *testing.T) {
+	// 0 is invalid.
+	for min, max := range map[int64]int64{1: 2, 10: 123, 100: 500} {
+		for i := 0; i < maxRangeTestCount; i++ {
+			inrange := Int63nRange(min, max)
+			if inrange < min || inrange >= max {
+				t.Errorf("%v out of range (%v,%v)", inrange, min, max)
+			}
+		}
+	}
+}