fix: Add addon checks to fix null pointer error bug in Kubernetes versions prior to 1.25. (#7114)

controllers/extensions/addon_controller_stages.go

@@ -277,6 +277,15 @@ func (r *deletionStage) Handle(ctx context.Context) {
 
 func (r *installableCheckStage) Handle(ctx context.Context) {
 	r.process(func(addon *extensionsv1alpha1.Addon) {
+		// XValidation was introduced as an alpha feature in Kubernetes v1.23 and requires additional enablement.
+		// It became more stable after Kubernetes 1.25. Users may encounter error in Kubernetes versions prior to 1.25.
+		// additional check to the addon YAML to ensure support for Kubernetes versions prior to 1.25
+		if err := checkAddonSpec(addon); err != nil {
+			setAddonErrorConditions(ctx, &r.stageCtx, addon, true, true, AddonCheckError, err.Error())
+			r.setReconciled()
+			return
+		}
+
 		r.reqCtx.Log.V(1).Info("installableCheckStage", "phase", addon.Status.Phase)
 		if addon.Spec.Installable == nil {
 			return
@@ -1099,6 +1108,14 @@ func findDataKey[V string | []byte](data map[string]V, refObj extensionsv1alpha1
 	return false
 }
 
+func checkAddonSpec(addon *extensionsv1alpha1.Addon) error {
+	if addon.Spec.Type == "Helm" {
+		if addon.Spec.Helm == nil || addon.Spec.Helm.ChartLocationURL == "" {
+			return fmt.Errorf("invalid Helm configuration: either 'Helm' is not specified or 'ChartLocationURL' is empty")
+		}
+	}
+	return nil
+}
 func setAddonProviderAndVersion(ctx context.Context, stageCtx *stageCtx, addon *extensionsv1alpha1.Addon) {
 	// if not set provider and version in spec, set it from labels
 	if addon.Labels == nil {
@@ -1117,4 +1134,5 @@ func setAddonProviderAndVersion(ctx context.Context, stageCtx *stageCtx, addon *
 	if len(addon.Labels[AddonVersion]) == 0 && len(addon.Spec.Version) != 0 {
 		addon.Labels[AddonVersion] = addon.Spec.Version
 	}
+
 }

controllers/extensions/addon_controller_test.go

@@ -32,6 +32,8 @@ import (
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/version"
+	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	"k8s.io/client-go/tools/record"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -314,6 +316,21 @@ var _ = Describe("Addon controller", func() {
 			Expect(testCtx.CreateObj(ctx, helmRelease)).Should(Succeed())
 		}
 
+		CheckKubernetesVersion := func() bool {
+			var serverVersion *version.Info
+			var isBeforeVersion bool
+			Eventually(func(g Gomega) {
+				clientset, err := kubernetes.NewForConfig(cfg)
+				g.Expect(err).NotTo(HaveOccurred())
+				discoveryClient := clientset.Discovery()
+				serverVersion, err = discoveryClient.ServerVersion()
+				g.Expect(err).NotTo(HaveOccurred())
+				isBeforeVersion = (version.CompareKubeAwareVersionStrings(serverVersion.String(), "v1.23.0") > 0)
+			}).Should(Succeed())
+			fmt.Printf("Kubernetes server version: %s\n", serverVersion.String())
+			return isBeforeVersion
+		}
+
 		It("should successfully reconcile a custom resource for Addon with spec.type=Helm", func() {
 			By("By create an addon")
 			createAddonSpecWithRequiredAttributes(func(newOjb *extensionsv1alpha1.Addon) {
@@ -631,6 +648,29 @@ var _ = Describe("Addon controller", func() {
 			addonStatusPhaseCheck(2, extensionsv1alpha1.AddonFailed, nil)
 		})
 
+		It("should failed reconcile a custom resource for Addon with missing spec helm of helm chartLocationURL", func() {
+			By("By check Kubernetes Version to decide if check")
+			// if k8s version > 1.23, it has kubebuilder X-Validation, no need to check again
+			if CheckKubernetesVersion() {
+				By("By create an addon with spec.helm = nil")
+				createAddonSpecWithRequiredAttributes(func(newOjb *extensionsv1alpha1.Addon) {
+					newOjb.Spec.Installable.AutoInstall = true
+					newOjb.Spec.Type = extensionsv1alpha1.HelmType
+					newOjb.Spec.Helm = nil
+				})
+
+				By("By check addon status")
+				Eventually(func(g Gomega) {
+					doReconcileOnce(g)
+					addon = &extensionsv1alpha1.Addon{}
+					g.Expect(testCtx.Cli.Get(ctx, key, addon)).To(Not(HaveOccurred()))
+					g.Expect(addon.Status.Phase).Should(Equal(extensionsv1alpha1.AddonFailed))
+					g.Expect(addon.Spec.InstallSpec).Should(BeNil())
+					g.Expect(addon.Status.ObservedGeneration).Should(BeEquivalentTo(1))
+				}).Should(Succeed())
+			}
+		})
+
 		It("should have provider and version in spec for Addon with provider and version in label initially", func() {
 			By("By create an addon with auto-install and labels contains provider and version information")
 			createAddonSpecWithRequiredAttributes(func(newOjb *extensionsv1alpha1.Addon) {
@@ -691,6 +731,7 @@ var _ = Describe("Addon controller", func() {
 				g.Expect(addon.Labels).Should(HaveKeyWithValue(AddonVersion, "0.9.0"))
 				g.Expect(addon.Status.Phase).Should(Equal(extensionsv1alpha1.AddonEnabling))
 			}).Should(Succeed())
+
 		})
 	})
 

controllers/extensions/const.go

@@ -49,6 +49,7 @@ const (
 	UninstallationFailed            = "UninstallationFailed"
 	UninstallationFailedLogs        = "UninstallationFailedLogs"
 	AddonRefObjError                = "ReferenceObjectError"
+	AddonCheckError                 = "AddonCheckError"
 
 	// config keys used in viper
 	maxConcurrentReconcilesKey = "MAXCONCURRENTRECONCILES_ADDON"