Always check if default labels on node need to be updated in kubelet

pkg/kubelet/BUILD

@@ -170,6 +170,7 @@ go_test(
         "//pkg/api:go_default_library",
         "//pkg/api/install:go_default_library",
         "//pkg/capabilities:go_default_library",
+        "//pkg/kubelet/apis:go_default_library",
         "//pkg/kubelet/apis/kubeletconfig:go_default_library",
         "//pkg/kubelet/cadvisor/testing:go_default_library",
         "//pkg/kubelet/cm:go_default_library",

pkg/kubelet/kubelet_node_status.go

@@ -137,6 +137,7 @@ func (kl *Kubelet) tryRegisterWithAPIServer(node *v1.Node) bool {
 		// the value of the controller-managed attach-detach
 		// annotation.
 		requiresUpdate := kl.reconcileCMADAnnotationWithExistingNode(node, existingNode)
+		requiresUpdate = kl.updateDefaultLabels(node, existingNode) || requiresUpdate
 		if requiresUpdate {
 			if _, err := nodeutil.PatchNodeStatus(kl.kubeClient, types.NodeName(kl.nodeName),
 				originalNode, existingNode); err != nil {
@@ -161,6 +162,33 @@ func (kl *Kubelet) tryRegisterWithAPIServer(node *v1.Node) bool {
 	return false
 }
 
+// updateDefaultLabels will set the default labels on the node
+func (kl *Kubelet) updateDefaultLabels(initialNode, existingNode *v1.Node) bool {
+	defaultLabels := []string{
+		kubeletapis.LabelHostname,
+		kubeletapis.LabelZoneFailureDomain,
+		kubeletapis.LabelZoneRegion,
+		kubeletapis.LabelInstanceType,
+		kubeletapis.LabelOS,
+		kubeletapis.LabelArch,
+	}
+
+	var needsUpdate bool = false
+	//Set default labels but make sure to not set labels with empty values
+	for _, label := range defaultLabels {
+		if existingNode.Labels[label] != initialNode.Labels[label] {
+			existingNode.Labels[label] = initialNode.Labels[label]
+			needsUpdate = true
+		}
+
+		if existingNode.Labels[label] == "" {
+			delete(existingNode.Labels, label)
+		}
+	}
+
+	return needsUpdate
+}
+
 // reconcileCMADAnnotationWithExistingNode reconciles the controller-managed
 // attach-detach annotation on a new node and the existing node, returning
 // whether the existing node must be updated.

pkg/kubelet/kubelet_node_status_test.go

@@ -43,6 +43,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/wait"
 	"k8s.io/client-go/kubernetes/fake"
 	core "k8s.io/client-go/testing"
+	kubeletapis "k8s.io/kubernetes/pkg/kubelet/apis"
 	"k8s.io/kubernetes/pkg/kubelet/cm"
 	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
 	"k8s.io/kubernetes/pkg/kubelet/util/sliceutils"
@@ -675,8 +676,15 @@ func TestRegisterWithApiServer(t *testing.T) {
 	kubeClient.AddReactor("get", "nodes", func(action core.Action) (bool, runtime.Object, error) {
 		// Return an existing (matching) node on get.
 		return true, &v1.Node{
-			ObjectMeta: metav1.ObjectMeta{Name: testKubeletHostname},
-			Spec:       v1.NodeSpec{ExternalID: testKubeletHostname},
+			ObjectMeta: metav1.ObjectMeta{
+				Name: testKubeletHostname,
+				Labels: map[string]string{
+					kubeletapis.LabelHostname: testKubeletHostname,
+					kubeletapis.LabelOS:       goruntime.GOOS,
+					kubeletapis.LabelArch:     goruntime.GOARCH,
+				},
+			},
+			Spec: v1.NodeSpec{ExternalID: testKubeletHostname},
 		}, nil
 	})
 	kubeClient.AddReactor("*", "*", func(action core.Action) (bool, runtime.Object, error) {
@@ -731,7 +739,13 @@ func TestTryRegisterWithApiServer(t *testing.T) {
 
 	newNode := func(cmad bool, externalID string) *v1.Node {
 		node := &v1.Node{
-			ObjectMeta: metav1.ObjectMeta{},
+			ObjectMeta: metav1.ObjectMeta{
+				Labels: map[string]string{
+					kubeletapis.LabelHostname: testKubeletHostname,
+					kubeletapis.LabelOS:       goruntime.GOOS,
+					kubeletapis.LabelArch:     goruntime.GOARCH,
+				},
+			},
 			Spec: v1.NodeSpec{
 				ExternalID: externalID,
 			},
@@ -961,3 +975,164 @@ func TestUpdateNewNodeStatusTooLargeReservation(t *testing.T) {
 	assert.NoError(t, err)
 	assert.True(t, apiequality.Semantic.DeepEqual(expectedNode.Status.Allocatable, updatedNode.Status.Allocatable), "%s", diff.ObjectDiff(expectedNode.Status.Allocatable, updatedNode.Status.Allocatable))
 }
+
+func TestUpdateDefaultLabels(t *testing.T) {
+	testKubelet := newTestKubelet(t, false /* controllerAttachDetachEnabled */)
+
+	cases := []struct {
+		name         string
+		initialNode  *v1.Node
+		existingNode *v1.Node
+		needsUpdate  bool
+		finalLabels  map[string]string
+	}{
+		{
+			name: "make sure default labels exist",
+			initialNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+					},
+				},
+			},
+			existingNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{},
+				},
+			},
+			needsUpdate: true,
+			finalLabels: map[string]string{
+				kubeletapis.LabelHostname:          "new-hostname",
+				kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+				kubeletapis.LabelZoneRegion:        "new-zone-region",
+				kubeletapis.LabelInstanceType:      "new-instance-type",
+				kubeletapis.LabelOS:                "new-os",
+				kubeletapis.LabelArch:              "new-arch",
+			},
+		},
+		{
+			name: "make sure default labels are up to date",
+			initialNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+					},
+				},
+			},
+			existingNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "old-hostname",
+						kubeletapis.LabelZoneFailureDomain: "old-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "old-zone-region",
+						kubeletapis.LabelInstanceType:      "old-instance-type",
+						kubeletapis.LabelOS:                "old-os",
+						kubeletapis.LabelArch:              "old-arch",
+					},
+				},
+			},
+			needsUpdate: true,
+			finalLabels: map[string]string{
+				kubeletapis.LabelHostname:          "new-hostname",
+				kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+				kubeletapis.LabelZoneRegion:        "new-zone-region",
+				kubeletapis.LabelInstanceType:      "new-instance-type",
+				kubeletapis.LabelOS:                "new-os",
+				kubeletapis.LabelArch:              "new-arch",
+			},
+		},
+		{
+			name: "make sure existing labels do not get deleted",
+			initialNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+					},
+				},
+			},
+			existingNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+						"please-persist":                   "foo",
+					},
+				},
+			},
+			needsUpdate: false,
+			finalLabels: map[string]string{
+				kubeletapis.LabelHostname:          "new-hostname",
+				kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+				kubeletapis.LabelZoneRegion:        "new-zone-region",
+				kubeletapis.LabelInstanceType:      "new-instance-type",
+				kubeletapis.LabelOS:                "new-os",
+				kubeletapis.LabelArch:              "new-arch",
+				"please-persist":                   "foo",
+			},
+		},
+		{
+			name: "no update needed",
+			initialNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+					},
+				},
+			},
+			existingNode: &v1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: map[string]string{
+						kubeletapis.LabelHostname:          "new-hostname",
+						kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+						kubeletapis.LabelZoneRegion:        "new-zone-region",
+						kubeletapis.LabelInstanceType:      "new-instance-type",
+						kubeletapis.LabelOS:                "new-os",
+						kubeletapis.LabelArch:              "new-arch",
+					},
+				},
+			},
+			needsUpdate: false,
+			finalLabels: map[string]string{
+				kubeletapis.LabelHostname:          "new-hostname",
+				kubeletapis.LabelZoneFailureDomain: "new-zone-failure-domain",
+				kubeletapis.LabelZoneRegion:        "new-zone-region",
+				kubeletapis.LabelInstanceType:      "new-instance-type",
+				kubeletapis.LabelOS:                "new-os",
+				kubeletapis.LabelArch:              "new-arch",
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		defer testKubelet.Cleanup()
+		kubelet := testKubelet.kubelet
+
+		needsUpdate := kubelet.updateDefaultLabels(tc.initialNode, tc.existingNode)
+		assert.Equal(t, tc.needsUpdate, needsUpdate, tc.name)
+		assert.Equal(t, tc.finalLabels, tc.existingNode.Labels, tc.name)
+	}
+}