Reintroduce KCP/CABPK ClusterConfiguration controlPlaneEndpoint

Signed-off-by: Stefan Büringer buringerst@vmware.com

Author: sbueringer

api/bootstrap/kubeadm/v1beta1/conversion_test.go

@@ -143,7 +143,6 @@ func spokeClusterConfiguration(in *ClusterConfiguration, c randfill.Continue) {
 	in.Networking.PodSubnet = ""
 	in.Networking.DNSDomain = ""
 	in.KubernetesVersion = ""
-	in.ControlPlaneEndpoint = ""
 	in.ClusterName = ""
 }
 

api/bootstrap/kubeadm/v1beta1/zz_generated.conversion.go

@@ -122,6 +122,23 @@ type ClusterConfiguration struct {
 	// +optional
 	Etcd Etcd `json:"etcd,omitempty"`
 
+	// controlPlaneEndpoint sets a stable IP address or DNS name for the control plane; it
+	// can be a valid IP address or a RFC-1123 DNS subdomain, both with optional TCP port.
+	// In case the ControlPlaneEndpoint is not specified, the AdvertiseAddress + BindPort
+	// are used; in case the ControlPlaneEndpoint is specified but without a TCP port,
+	// the BindPort is used.
+	// Possible usages are:
+	// e.g. In a cluster with more than one control plane instances, this field should be
+	// assigned the address of the external load balancer in front of the
+	// control plane instances.
+	// e.g.  in environments with enforced node recycling, the ControlPlaneEndpoint
+	// could be used for assigning a stable DNS to the control plane.
+	// NB: This value defaults to the first value in the Cluster object status.apiEndpoints array.
+	// +optional
+	// +kubebuilder:validation:MinLength=1
+	// +kubebuilder:validation:MaxLength=512
+	ControlPlaneEndpoint string `json:"controlPlaneEndpoint,omitempty"`
+
 	// apiServer contains extra settings for the API server control plane component
 	// +optional
 	APIServer APIServer `json:"apiServer,omitempty"`

api/bootstrap/kubeadm/v1beta2/kubeadm_types.go

@@ -222,7 +222,6 @@ func spokeClusterConfiguration(in *bootstrapv1beta1.ClusterConfiguration, c rand
 	in.Networking.PodSubnet = ""
 	in.Networking.DNSDomain = ""
 	in.KubernetesVersion = ""
-	in.ControlPlaneEndpoint = ""
 	in.ClusterName = ""
 }
 

api/controlplane/kubeadm/v1beta1/conversion_test.go

@@ -546,7 +546,7 @@ func (r *KubeadmConfigReconciler) handleClusterNotInitialized(ctx context.Contex
 		scope.Config.Spec.InitConfiguration = &bootstrapv1.InitConfiguration{}
 	}
 
-	additionalData := r.computeClusterConfigurationAdditionalData(scope.Cluster, machine, scope.Config.Spec.InitConfiguration)
+	additionalData := r.computeClusterConfigurationAndAdditionalData(scope.Cluster, machine, scope.Config.Spec.ClusterConfiguration, scope.Config.Spec.InitConfiguration)
 
 	clusterdata, err := kubeadmtypes.MarshalClusterConfigurationForVersion(scope.Config.Spec.ClusterConfiguration, parsedVersion, additionalData)
 	if err != nil {
@@ -1313,15 +1313,16 @@ func (r *KubeadmConfigReconciler) reconcileDiscoveryFile(ctx context.Context, cl
 	return ctrl.Result{}, nil
 }
 
-// computeClusterConfigurationAdditionalData computes additional data that must go in kubeadm's ClusterConfiguration, but exists
+// computeClusterConfigurationAndAdditionalData computes additional data that must go in kubeadm's ClusterConfiguration, but exists
 // in different Cluster API objects, like e.g. the Cluster object.
-func (r *KubeadmConfigReconciler) computeClusterConfigurationAdditionalData(cluster *clusterv1.Cluster, machine *clusterv1.Machine, initConfiguration *bootstrapv1.InitConfiguration) *upstream.AdditionalData {
+func (r *KubeadmConfigReconciler) computeClusterConfigurationAndAdditionalData(cluster *clusterv1.Cluster, machine *clusterv1.Machine, clusterConfiguration *bootstrapv1.ClusterConfiguration, initConfiguration *bootstrapv1.InitConfiguration) *upstream.AdditionalData {
 	data := &upstream.AdditionalData{}
 
-	// If there is a ControlPlaneEndpoint defined at Cluster level (e.g. the load balancer endpoint),
+	// If there is no ControlPlaneEndpoint defined in ClusterConfiguration but
+	// there is a ControlPlaneEndpoint defined at Cluster level (e.g. the load balancer endpoint),
 	// then use Cluster's ControlPlaneEndpoint as a control plane endpoint for the Kubernetes cluster.
-	if cluster.Spec.ControlPlaneEndpoint.IsValid() {
-		data.ControlPlaneEndpoint = ptr.To(cluster.Spec.ControlPlaneEndpoint.String())
+	if clusterConfiguration.ControlPlaneEndpoint == "" && cluster.Spec.ControlPlaneEndpoint.IsValid() {
+		clusterConfiguration.ControlPlaneEndpoint = cluster.Spec.ControlPlaneEndpoint.String()
 	}
 
 	// Use Cluster.Name

bootstrap/kubeadm/config/crd/bases/bootstrap.cluster.x-k8s.io_kubeadmconfigs.yaml

@@ -1828,7 +1828,7 @@ func TestKubeadmConfigReconciler_Reconcile_DiscoveryReconcileFailureBehaviors(t
 }
 
 // Set cluster configuration defaults based on dynamic values from the cluster object.
-func TestKubeadmConfigReconciler_computeClusterConfigurationAdditionalData(t *testing.T) {
+func TestKubeadmConfigReconciler_computeClusterConfigurationAndAdditionalData(t *testing.T) {
 	k := &KubeadmConfigReconciler{}
 
 	testcases := []struct {
@@ -1870,9 +1870,10 @@ func TestKubeadmConfigReconciler_computeClusterConfigurationAdditionalData(t *te
 		t.Run(tc.name, func(t *testing.T) {
 			g := NewWithT(t)
 
-			gotData := k.computeClusterConfigurationAdditionalData(tc.cluster, tc.machine, tc.initConfiguration)
+			clusterConfiguration := &bootstrapv1.ClusterConfiguration{}
+			gotData := k.computeClusterConfigurationAndAdditionalData(tc.cluster, tc.machine, clusterConfiguration, tc.initConfiguration)
+			g.Expect(clusterConfiguration.ControlPlaneEndpoint).To(Equal("myControlPlaneEndpoint:6443"))
 			g.Expect(gotData.KubernetesVersion).To(Equal(ptr.To("v1.23.0")))
-			g.Expect(gotData.ControlPlaneEndpoint).To(Equal(ptr.To("myControlPlaneEndpoint:6443")))
 			g.Expect(gotData.ClusterName).To(Equal(ptr.To("mycluster")))
 			g.Expect(gotData.PodSubnet).To(Equal(ptr.To("myPodSubnet")))
 			g.Expect(gotData.ServiceSubnet).To(Equal(ptr.To("myServiceSubnet")))

bootstrap/kubeadm/config/crd/bases/bootstrap.cluster.x-k8s.io_kubeadmconfigtemplates.yaml

@@ -35,12 +35,11 @@ type AdditionalDataGetter interface {
 // in different Cluster API objects, like e.g. the Cluster object.
 type AdditionalData struct {
 	// Data from Cluster API's Cluster object.
-	KubernetesVersion    *string
-	ClusterName          *string
-	ControlPlaneEndpoint *string
-	DNSDomain            *string
-	ServiceSubnet        *string
-	PodSubnet            *string
+	KubernetesVersion *string
+	ClusterName       *string
+	DNSDomain         *string
+	ServiceSubnet     *string
+	PodSubnet         *string
 
 	// Data migrated from ClusterConfiguration to InitConfiguration in kubeadm's v1beta4 API version.
 	// Note: Corresponding Cluster API types are aligned with kubeadm's v1beta4 API version.
@@ -52,7 +51,6 @@ func (a *AdditionalData) Clone() *AdditionalData {
 	return &AdditionalData{
 		KubernetesVersion:                       a.KubernetesVersion,
 		ClusterName:                             a.ClusterName,
-		ControlPlaneEndpoint:                    a.ControlPlaneEndpoint,
 		DNSDomain:                               a.DNSDomain,
 		ServiceSubnet:                           a.ServiceSubnet,
 		PodSubnet:                               a.PodSubnet,

bootstrap/kubeadm/internal/controllers/kubeadmconfig_controller.go

@@ -193,9 +193,6 @@ func (src *ClusterConfiguration) SetAdditionalData(data upstream.AdditionalData)
 	if data.ClusterName != nil {
 		src.ClusterName = *data.ClusterName
 	}
-	if data.ControlPlaneEndpoint != nil {
-		src.ControlPlaneEndpoint = *data.ControlPlaneEndpoint
-	}
 	if data.DNSDomain != nil {
 		src.Networking.DNSDomain = *data.DNSDomain
 	}
@@ -226,9 +223,6 @@ func (src *ClusterConfiguration) GetAdditionalData(data *upstream.AdditionalData
 	if src.ClusterName != "" {
 		data.ClusterName = ptr.To(src.ClusterName)
 	}
-	if src.ControlPlaneEndpoint != "" {
-		data.ControlPlaneEndpoint = ptr.To(src.ControlPlaneEndpoint)
-	}
 	if src.Networking.DNSDomain != "" {
 		data.DNSDomain = ptr.To(src.Networking.DNSDomain)
 	}