Reflect available upgrades in cluster status: addressed comments

* Several watcher improvements: events, code enhancements
* Changed availableUpgrades type into []string

api/v1alpha1/managedcluster_types.go

@@ -101,7 +101,7 @@ type ManagedClusterStatus struct {
 	// AvailableUpgrades is the list of ClusterTemplate names to which
 	// this cluster can be upgraded. It can be an empty array, which means no upgrades are
 	// available.
-	AvailableUpgrades []AvailableUpgrade `json:"availableUpgrades,omitempty"`
+	AvailableUpgrades []string `json:"availableUpgrades,omitempty"`
 	// ObservedGeneration is the last observed generation.
 	ObservedGeneration int64 `json:"observedGeneration,omitempty"`
 }

internal/controller/managedcluster_controller.go

@@ -39,17 +39,19 @@ import (
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
-	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/client-go/dynamic"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/rest"
 	"k8s.io/client-go/tools/clientcmd"
 	capz "sigs.k8s.io/cluster-api-provider-azure/api/v1beta1"
 	capv "sigs.k8s.io/cluster-api-provider-vsphere/apis/v1beta1"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/builder"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
+	"sigs.k8s.io/controller-runtime/pkg/event"
 	"sigs.k8s.io/controller-runtime/pkg/handler"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 	"sigs.k8s.io/yaml"
 
@@ -1027,9 +1029,9 @@ func (r *ManagedClusterReconciler) setAvailableUpgrades(ctx context.Context, man
 			}
 		}
 	}
-	availableUpgrades := make([]hmc.AvailableUpgrade, 0, len(availableUpgradesMap))
+	availableUpgrades := make([]string, 0, len(availableUpgradesMap))
 	for _, availableUpgrade := range availableUpgradesMap {
-		availableUpgrades = append(availableUpgrades, availableUpgrade)
+		availableUpgrades = append(availableUpgrades, availableUpgrade.Name)
 	}
 
 	managedCluster.Status.AvailableUpgrades = availableUpgrades
@@ -1060,23 +1062,22 @@ func (r *ManagedClusterReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		).
 		Watches(&hmc.ClusterTemplateChain{},
 			handler.EnqueueRequestsFromMapFunc(func(ctx context.Context, o client.Object) []ctrl.Request {
-				chain := &hmc.ClusterTemplateChain{}
-				err := r.Client.Get(ctx, types.NamespacedName{Namespace: o.GetNamespace(), Name: o.GetName()}, chain)
-				if err != nil {
-					return []ctrl.Request{}
+				chain, ok := o.(*hmc.ClusterTemplateChain)
+				if !ok {
+					return nil
 				}
 
 				var req []ctrl.Request
 				for _, template := range getTemplateNamesManagedByChain(chain) {
 					managedClusters := &hmc.ManagedClusterList{}
-					err = r.Client.List(ctx, managedClusters,
-						client.InNamespace(o.GetNamespace()),
+					err := r.Client.List(ctx, managedClusters,
+						client.InNamespace(chain.Namespace),
 						client.MatchingFields{hmc.TemplateKey: template})
 					if err != nil {
 						return []ctrl.Request{}
 					}
 					for _, cluster := range managedClusters.Items {
-						req = append(req, reconcile.Request{
+						req = append(req, ctrl.Request{
 							NamespacedName: client.ObjectKey{
 								Namespace: cluster.Namespace,
 								Name:      cluster.Name,
@@ -1086,6 +1087,10 @@ func (r *ManagedClusterReconciler) SetupWithManager(mgr ctrl.Manager) error {
 				}
 				return req
 			}),
+			builder.WithPredicates(predicate.Funcs{
+				UpdateFunc:  func(event.UpdateEvent) bool { return false },
+				GenericFunc: func(event.GenericEvent) bool { return false },
+			}),
 		).
 		Complete(r)
 }

internal/webhook/managedcluster_webhook.go

@@ -101,8 +101,7 @@ func (v *ManagedClusterValidator) ValidateUpdate(ctx context.Context, oldObj, ne
 	}
 
 	if oldTemplate != newTemplate {
-		isUpgradeAvailable := validateAvailableUpgrade(oldManagedCluster, newTemplate)
-		if !isUpgradeAvailable {
+		if !slices.Contains(oldManagedCluster.Status.AvailableUpgrades, newTemplate) {
 			msg := fmt.Sprintf("Cluster can't be upgraded from %s to %s. This upgrade sequence is not allowed", oldTemplate, newTemplate)
 			return admission.Warnings{msg}, errClusterUpgradeForbidden
 		}
@@ -123,12 +122,6 @@ func (v *ManagedClusterValidator) ValidateUpdate(ctx context.Context, oldObj, ne
 	return nil, nil
 }
 
-func validateAvailableUpgrade(oldManagedCluster *hmcv1alpha1.ManagedCluster, newTemplate string) bool {
-	return slices.ContainsFunc(oldManagedCluster.Status.AvailableUpgrades, func(au hmcv1alpha1.AvailableUpgrade) bool {
-		return newTemplate == au.Name
-	})
-}
-
 func validateK8sCompatibility(ctx context.Context, cl client.Client, template *hmcv1alpha1.ClusterTemplate, mc *hmcv1alpha1.ManagedCluster) error {
 	if len(mc.Spec.Services) == 0 || template.Status.KubernetesVersion == "" {
 		return nil // nothing to do

internal/webhook/managedcluster_webhook_test.go

@@ -282,7 +282,7 @@ func TestManagedClusterValidateUpdate(t *testing.T) {
 			name: "update spec.template: should fail if the new cluster template was found but is invalid (some validation error)",
 			oldManagedCluster: managedcluster.NewManagedCluster(
 				managedcluster.WithClusterTemplate(testTemplateName),
-				managedcluster.WithAvailableUpgrades([]v1alpha1.AvailableUpgrade{{Name: newTemplateName}}),
+				managedcluster.WithAvailableUpgrades([]string{newTemplateName}),
 			),
 			newManagedCluster: managedcluster.NewManagedCluster(managedcluster.WithClusterTemplate(newTemplateName)),
 			existingObjects: []runtime.Object{
@@ -302,7 +302,7 @@ func TestManagedClusterValidateUpdate(t *testing.T) {
 			oldManagedCluster: managedcluster.NewManagedCluster(
 				managedcluster.WithClusterTemplate(testTemplateName),
 				managedcluster.WithCredential(testCredentialName),
-				managedcluster.WithAvailableUpgrades([]v1alpha1.AvailableUpgrade{}),
+				managedcluster.WithAvailableUpgrades([]string{}),
 			),
 			newManagedCluster: managedcluster.NewManagedCluster(
 				managedcluster.WithClusterTemplate(upgradeTargetTemplateName),
@@ -337,7 +337,7 @@ func TestManagedClusterValidateUpdate(t *testing.T) {
 			oldManagedCluster: managedcluster.NewManagedCluster(
 				managedcluster.WithClusterTemplate(testTemplateName),
 				managedcluster.WithCredential(testCredentialName),
-				managedcluster.WithAvailableUpgrades([]v1alpha1.AvailableUpgrade{{Name: newTemplateName}}),
+				managedcluster.WithAvailableUpgrades([]string{newTemplateName}),
 			),
 			newManagedCluster: managedcluster.NewManagedCluster(
 				managedcluster.WithClusterTemplate(newTemplateName),

templates/provider/hmc/templates/crds/hmc.mirantis.com_managedclusters.yaml

@@ -138,16 +138,7 @@ spec:
                   this cluster can be upgraded. It can be an empty array, which means no upgrades are
                   available.
                 items:
-                  description: AvailableUpgrade is the definition of the available
-                    upgrade for the Template
-                  properties:
-                    name:
-                      description: Name is the name of the Template to which the upgrade
-                        is available.
-                      type: string
-                  required:
-                  - name
-                  type: object
+                  type: string
                 type: array
               conditions:
                 description: Conditions contains details for the current state of

test/objects/managedcluster/managedcluster.go

@@ -88,7 +88,7 @@ func WithCredential(credName string) Opt {
 	}
 }
 
-func WithAvailableUpgrades(availableUpgrades []v1alpha1.AvailableUpgrade) Opt {
+func WithAvailableUpgrades(availableUpgrades []string) Opt {
 	return func(p *v1alpha1.ManagedCluster) {
 		p.Status.AvailableUpgrades = availableUpgrades
 	}