Fix stale NodeStatus entries in StaticRoute resources when their corresponding Kubernetes nodes are removed.

controllers/staticroute/mocks_test.go

@@ -36,6 +36,7 @@ type reconcileImplClientMock struct {
 	getErr          error
 	updateErr       error
 	listErr         error
+	listCalls       int
 }
 
 func (m reconcileImplClientMock) Get(ctx context.Context, key client.ObjectKey, obj client.Object, options ...client.GetOption) error {
@@ -53,10 +54,11 @@ func (m reconcileImplClientMock) Update(ctx context.Context, obj client.Object,
 	return m.client.Update(ctx, obj, options...)
 }
 
-func (m reconcileImplClientMock) List(ctx context.Context, list client.ObjectList, options ...client.ListOption) error {
-	if m.listErr != nil {
+func (m *reconcileImplClientMock) List(ctx context.Context, list client.ObjectList, options ...client.ListOption) error {
+	if m.listErr != nil && m.listCalls > 0 {
 		return m.listErr
 	}
+	m.listCalls++
 	return m.client.List(ctx, list, options...)
 }
 
@@ -140,15 +142,15 @@ func (m routeManagerMock) Run(chan struct{}) error {
 	return nil
 }
 
-func newFakeClient(route *staticroutev1.StaticRoute) client.Client {
+func newFakeClient(route *staticroutev1.StaticRoute, nodes *corev1.NodeList) client.Client {
 	s := runtime.NewScheme()
 	s.AddKnownTypes(staticroutev1.GroupVersion, route)
-	nodes := &corev1.NodeList{}
-	s.AddKnownTypes(corev1.SchemeGroupVersion, nodes)
+	s.AddKnownTypes(corev1.SchemeGroupVersion, &corev1.NodeList{})
+	s.AddKnownTypes(corev1.SchemeGroupVersion, &corev1.Node{})
 	return fake.NewClientBuilder().
 		WithScheme(s).
 		WithStatusSubresource(route).
-		WithRuntimeObjects([]runtime.Object{route}...).
+		WithRuntimeObjects([]runtime.Object{nodes, route}...).
 		Build()
 }
 
@@ -185,7 +187,7 @@ func newStaticRouteWithValues(withSpec, withStatus bool) *staticroutev1.StaticRo
 	if withStatus {
 		route.Status = staticroutev1.StaticRouteStatus{
 			NodeStatus: []staticroutev1.StaticRouteNodeStatus{
-				staticroutev1.StaticRouteNodeStatus{
+				{
 					Hostname: "hostname",
 					State: staticroutev1.StaticRouteSpec{
 						Subnet:  "10.0.0.1/16",

controllers/staticroute/staticroute_controller.go

@@ -160,6 +160,14 @@ func reconcileImpl(params reconcileImplParams) (res *reconcile.Result, err error
 
 	rw := routeWrapper{instance: instance}
 
+	// Cleanup is only needed when the StaticRoute is being deleted.
+	// Do not list all Nodes during normal reconciliation.
+	if !instance.DeletionTimestamp.IsZero() {
+		if res, err = removeStaleNodeStatuses(params, instance, reqLogger); err != nil {
+			return res, err
+		}
+	}
+
 	defer func() {
 		if !reportStatus {
 			return
@@ -227,7 +235,7 @@ func reconcileImpl(params reconcileImplParams) (res *reconcile.Result, err error
 		isChanged ||
 		selectorNoLongerMatches {
 		reportStatus = false
-		if !rw.removeFromStatus(params.options.Hostname) {
+		if !rw.removeFromStatus(params.options.Hostname) && len(rw.instance.Status.NodeStatus) > 0 {
 			return alreadyDeleted, nil
 		}
 		res, err = deleteOperation(params, &rw, reqLogger)
@@ -440,3 +448,51 @@ func convertToOperator(operator metav1.LabelSelectorOperator) (selection.Operato
 		return selection.Equals, errors.New("unable to convert operator")
 	}
 }
+
+// removeStaleNodeStatuses removes status entries for nodes that no longer
+// exist. It also releases the finalizer when a deleting StaticRoute has no
+// remaining node statuses.
+func removeStaleNodeStatuses(
+	params reconcileImplParams,
+	instance *staticroutev1.StaticRoute,
+	logger types.Logger,
+) (*reconcile.Result, error) {
+	nodes := &corev1.NodeList{}
+	if err := params.client.List(context.Background(), nodes); err != nil {
+		logger.Error(err, "Unable to list Kubernetes nodes")
+		return nodeGetError, err
+	}
+
+	existingNodes := make(map[string]struct{}, len(nodes.Items))
+	for i := range nodes.Items {
+		node := &nodes.Items[i]
+
+		existingNodes[node.Name] = struct{}{}
+
+		if hostname := node.Labels[HostNameLabel]; hostname != "" {
+			existingNodes[hostname] = struct{}{}
+		}
+	}
+
+	originalLength := len(instance.Status.NodeStatus)
+	updatedStatus := make([]staticroutev1.StaticRouteNodeStatus, 0, originalLength)
+	for _, status := range instance.Status.NodeStatus {
+		if _, exists := existingNodes[status.Hostname]; exists {
+			updatedStatus = append(updatedStatus, status)
+			continue
+		}
+		logger.Info("Removing stale node status", "hostname", status.Hostname)
+	}
+
+	if len(updatedStatus) == originalLength {
+		return alreadyDeleted, nil
+	}
+
+	instance.Status.NodeStatus = updatedStatus
+	if err := params.client.Status().Update(context.Background(), instance); err != nil {
+		logger.Error(err, "Unable to update StaticRoute status after stale-node cleanup")
+		return delStatusUpdateError, err
+	}
+
+	return finished, nil
+}