Adding MachineNamingStrategy in KubeadmControlPlane

Signed-off-by: Muhammad Adil Ghaffar <[email protected]>

controlplane/kubeadm/api/v1beta1/kubeadm_control_plane_types.go

@@ -123,6 +123,11 @@ type KubeadmControlPlaneSpec struct {
 	// The RemediationStrategy that controls how control plane machine remediation happens.
 	// +optional
 	RemediationStrategy *RemediationStrategy `json:"remediationStrategy,omitempty"`
+
+	// MachineNamingStrategy allows changing the naming pattern used when creating Machines.
+	// InfraMachines & KubeadmConfigs will use the same name as the corresponding Machines.
+	// +optional
+	MachineNamingStrategy *MachineNamingStrategy `json:"machineNamingStrategy,omitempty"`
 }
 
 // KubeadmControlPlaneMachineTemplate defines the template for Machines
@@ -234,6 +239,23 @@ type RemediationStrategy struct {
 	MinHealthyPeriod *metav1.Duration `json:"minHealthyPeriod,omitempty"`
 }
 
+// MachineNamingStrategy allows changing the naming pattern used when creating Machines.
+// InfraMachines & KubeadmConfigs will use the same name as the corresponding Machines.
+type MachineNamingStrategy struct {
+	// Template defines the template to use for generating the names of the Machine objects.
+	// If not defined, it will fallback to `{{ .kubeadmControlPlane.name }}-{{ .random }}`.
+	// If the generated name string exceeds 63 characters, it will be trimmed to 58 characters and will
+	// get concatenated with a random suffix of length 5.
+	// Length of the template string must not exceed 256 characters.
+	// The template allows the following variables `.cluster.name`, `.kubeadmControlPlane.name` and `.random`.
+	// The variable `.cluster.name` retrieves the name of the cluster object that owns the Machines being created.
+	// The variable `.kubeadmControlPlane.name` retrieves the name of the KubeadmControlPlane object that owns the Machines being created.
+	// The variable `.random` is substituted with random alphanumeric string, without vowels, of length 5.
+	// +optional
+	// +kubebuilder:validation:MaxLength=256
+	Template string `json:"template,omitempty"`
+}
+
 // KubeadmControlPlaneStatus defines the observed state of KubeadmControlPlane.
 type KubeadmControlPlaneStatus struct {
 	// Selector is the label selector in string format to avoid introspection

controlplane/kubeadm/api/v1beta1/kubeadmcontrolplanetemplate_types.go

@@ -101,6 +101,11 @@ type KubeadmControlPlaneTemplateResourceSpec struct {
 	// The RemediationStrategy that controls how control plane machine remediation happens.
 	// +optional
 	RemediationStrategy *RemediationStrategy `json:"remediationStrategy,omitempty"`
+
+	// MachineNamingStrategy allows changing the naming pattern used when creating Machines.
+	// InfraMachines & KubeadmConfigs will use the same name as the corresponding Machines.
+	// +optional
+	MachineNamingStrategy *MachineNamingStrategy `json:"machineNamingStrategy,omitempty"`
 }
 
 // KubeadmControlPlaneTemplateMachineTemplate defines the template for Machines

controlplane/kubeadm/internal/controllers/helpers.go

@@ -37,6 +37,7 @@ import (
 	"sigs.k8s.io/cluster-api/controllers/external"
 	controlplanev1 "sigs.k8s.io/cluster-api/controlplane/kubeadm/api/v1beta1"
 	"sigs.k8s.io/cluster-api/controlplane/kubeadm/internal"
+	topologynames "sigs.k8s.io/cluster-api/internal/topology/names"
 	"sigs.k8s.io/cluster-api/internal/util/ssa"
 	"sigs.k8s.io/cluster-api/util"
 	"sigs.k8s.io/cluster-api/util/certs"
@@ -184,6 +185,7 @@ func (r *KubeadmControlPlaneReconciler) cloneConfigsAndGenerateMachine(ctx conte
 	if r.DeprecatedInfraMachineNaming {
 		infraMachineName = names.SimpleNameGenerator.GenerateName(kcp.Spec.MachineTemplate.InfrastructureRef.Name + "-")
 	}
+
 	// Clone the infrastructure template
 	infraRef, err := external.CreateFromTemplate(ctx, &external.CreateFromTemplateInput{
 		Client:      r.Client,
@@ -349,7 +351,18 @@ func (r *KubeadmControlPlaneReconciler) computeDesiredMachine(kcp *controlplanev
 	annotations := map[string]string{}
 	if existingMachine == nil {
 		// Creating a new machine
-		machineName = names.SimpleNameGenerator.GenerateName(kcp.Name + "-")
+		nameTemplate := "{{ .kubeadmControlPlane.name }}-{{ .random }}"
+		if kcp.Spec.MachineNamingStrategy != nil && kcp.Spec.MachineNamingStrategy.Template != "" {
+			nameTemplate = kcp.Spec.MachineNamingStrategy.Template
+			if !strings.Contains(nameTemplate, "{{ .random }}") {
+				return nil, errors.New("cannot generate KCP machine name: {{ .random }} is missing in machineNamingStrategy.template")
+			}
+		}
+		generatedMachineName, err := topologynames.KCPMachineNameGenerator(nameTemplate, cluster.Name, kcp.Name).GenerateName()
+		if err != nil {
+			return nil, errors.Wrap(err, "failed to generate name for KCP Machine")
+		}
+		machineName = generatedMachineName
 		version = &kcp.Spec.Version
 
 		// Machine's bootstrap config may be missing ClusterConfiguration if it is not the first machine in the control plane.