fix: CA node recognizing fake nodegroups

- add provider ID to nodes in the format `kwok:<node-name>`
- fix invalid `KwokManagedAnnotation`
- sanitize template nodes (remove `resourceVersion` etc.,)
- not sanitizing the node leads to error during creation of new nodes
- abstract code to get NG name into a separate function `getNGNameFromAnnotation`
Signed-off-by: vadasambar <surajrbanakar@gmail.com>

cluster-autoscaler/cloudprovider/kwok/kwok.go

@@ -62,7 +62,7 @@ const (
 	// KwokManagedAnnotation is the default annotation
 	// that kwok manages to decide if it should manage
 	// a node it sees in the cluster
-	KwokManagedAnnotation = "kwok.x-k8s.io/node=fake"
+	KwokManagedAnnotation = "kwok.x-k8s.io/node"
 
 	// // GPULabel is the label added to nodes with GPU resource.
 	// GPULabel = "cloud.google.com/gke-accelerator"
@@ -85,8 +85,7 @@ type KwokCloudProvider struct {
 	// kubeClient is to be used only for create, delete and update
 	kubeClient *kubeclient.Clientset
 	// lister is to be used for get and list
-	lister   kube_util.NodeLister
-	provider string
+	lister kube_util.NodeLister
 }
 
 // Name returns name of the cloud provider.
@@ -107,17 +106,13 @@ func (kwok *KwokCloudProvider) NodeGroups() []cloudprovider.NodeGroup {
 func (kwok *KwokCloudProvider) NodeGroupForNode(node *apiv1.Node) (cloudprovider.NodeGroup, error) {
 	// Skip nodes that are not managed by kwok cloud provider.
 	if !strings.HasPrefix(node.Spec.ProviderID, ProviderName) {
+		klog.V(2).Infof("ignoring node '%s' because it is not managed by kwok", node.GetName())
 		return nil, nil
 	}
 
-	annotations := node.GetAnnotations()
-	nodeGroupName := annotations[NGNameAnnotation]
-	if nodeGroupName == "" {
-		return nil, fmt.Errorf("nodegroup name annotation '%s' not found on the node '%s'", NGNameAnnotation, node.GetName())
-	}
-
 	for _, nodeGroup := range kwok.nodeGroups {
-		if nodeGroup.name == nodeGroupName {
+		if nodeGroup.name == getNGNameFromAnnotation(node) {
+			klog.V(5).Infof("found nodegroup '%s' for node '%s'", nodeGroup.name, node.GetName())
 			return nodeGroup, nil
 		}
 	}
@@ -176,19 +171,22 @@ func (kwok *KwokCloudProvider) GetNodeGpuConfig(node *apiv1.Node) *cloudprovider
 // Refresh is called before every main loop and can be used to dynamically update cloud provider state.
 // In particular the list of node groups returned by NodeGroups can change as a result of CloudProvider.Refresh().
 func (kwok *KwokCloudProvider) Refresh() error {
-	nodeList, err := kwok.lister.List()
-	if err != nil {
-		return err
-	}
 
-	ngs := []*NodeGroup{}
-	for _, no := range nodeList {
-		ng := parseAnnotationsToNodegroup(no)
-		ng.kubeClient = kwok.kubeClient
-		ngs = append(ngs, ng)
-	}
+	// TODO(vadasambar): causes CA to not recognize kwok nodegroups
+	// needs better implementation
+	// nodeList, err := kwok.lister.List()
+	// if err != nil {
+	// 	return err
+	// }
+
+	// ngs := []*NodeGroup{}
+	// for _, no := range nodeList {
+	// 	ng := parseAnnotationsToNodegroup(no)
+	// 	ng.kubeClient = kwok.kubeClient
+	// 	ngs = append(ngs, ng)
+	// }
 
-	kwok.nodeGroups = ngs
+	// kwok.nodeGroups = ngs
 
 	return nil
 }
@@ -254,9 +252,10 @@ func (nodeGroup *NodeGroup) IncreaseSize(delta int) error {
 	for i := 0; i < delta; i++ {
 		node := schedNode.Node()
 		node.Name = fmt.Sprintf("%s-%s", nodeGroup.name, rand.String(5))
+		node.Spec.ProviderID = fmt.Sprintf("kwok:%s", node.Name)
 		_, err := nodeGroup.kubeClient.CoreV1().Nodes().Create(context.Background(), node, v1.CreateOptions{})
 		if err != nil {
-			return fmt.Errorf("couldn't create new node '%s'", node.Name)
+			return fmt.Errorf("couldn't create new node '%s': %v", node.Name, err)
 		}
 	}
 
@@ -319,7 +318,7 @@ func (nodeGroup *NodeGroup) getNodeNamesForNodeGroup() ([]string, error) {
 	}
 
 	for _, no := range nodeList {
-		if no.GetAnnotations()[NGNameAnnotation] == nodeGroup.Id() {
+		if getNGNameFromAnnotation(no) == nodeGroup.Id() {
 			names = append(names, no.GetName())
 		}
 	}
@@ -484,7 +483,9 @@ func parseNodeTemplates(data []byte, kubeClient *kubeclient.Clientset, lister ku
 
 	ngs := []*NodeGroup{}
 	for _, no := range nodeTemplates {
+		sanitizeNode(no)
 		no.Annotations[KwokManagedAnnotation] = "fake"
+		no.Spec.ProviderID = fmt.Sprintf("kwok:%s", no.GetName())
 		ng := parseAnnotationsToNodegroup(no)
 		ng.kubeClient = kubeClient
 		ng.lister = lister
@@ -495,21 +496,14 @@ func parseNodeTemplates(data []byte, kubeClient *kubeclient.Clientset, lister ku
 
 }
 
-func parseAnnotationsToNodegroup(no *apiv1.Node) *NodeGroup {
-	ngName := no.GetAnnotations()[NGNameAnnotation]
-
-	if ngName == "" {
-		if no.GetAnnotations()["eks.amazonaws.com/nodegroup"] != "" {
-			// add prefix to make it clear that this is a different nodegroup
-			ngName = fmt.Sprintf("kwok-fake-%s", no.GetAnnotations()["eks.amazonaws.com/nodegroup"])
-		} else if no.GetAnnotations()["cloud.google.com/gke-nodepool"] != "" {
-			// add prefix to make it clear that this is a different nodegroup
-			ngName = fmt.Sprintf("kwok-fake-%s", no.GetAnnotations()["cloud.google.com/gke-nodepool"])
-		} else {
-			klog.Fatalf("did not find nodegroup annotation on the template node '%s'", no.GetName())
-		}
-	}
+func sanitizeNode(no *apiv1.Node) {
+	no.ResourceVersion = ""
+	no.Generation = 0
+	no.UID = ""
+	no.CreationTimestamp = v1.Time{}
+}
 
+func parseAnnotationsToNodegroup(no *apiv1.Node) *NodeGroup {
 	min := 0
 	max := 200
 	target := min
@@ -550,10 +544,30 @@ func parseAnnotationsToNodegroup(no *apiv1.Node) *NodeGroup {
 	no.Name = fmt.Sprintf("kwok-fake-%s", no.GetName())
 
 	return &NodeGroup{
-		name:         ngName,
+		name:         getNGNameFromAnnotation(no),
 		minSize:      min,
 		maxSize:      max,
 		targetSize:   target,
 		nodeTemplate: no,
 	}
 }
+
+func getNGNameFromAnnotation(no *apiv1.Node) string {
+	ngName := no.GetAnnotations()[NGNameAnnotation]
+
+	if ngName != "" {
+		return ngName
+	}
+
+	if no.GetAnnotations()["eks.amazonaws.com/nodegroup"] != "" {
+		// add prefix to make it clear that this is a different nodegroup
+		ngName = fmt.Sprintf("kwok-fake-%s", no.GetAnnotations()["eks.amazonaws.com/nodegroup"])
+	} else if no.GetAnnotations()["cloud.google.com/gke-nodepool"] != "" {
+		// add prefix to make it clear that this is a different nodegroup
+		ngName = fmt.Sprintf("kwok-fake-%s", no.GetAnnotations()["cloud.google.com/gke-nodepool"])
+	} else {
+		klog.Fatalf("did not find nodegroup annotation on the template node '%s'", no.GetName())
+	}
+
+	return ngName
+}