Implement MachinePool Machines in CAPI, CAPD, and clusterctl

api/v1beta1/common_types.go

@@ -57,6 +57,18 @@ const (
 	// update that disallows a pre-existing Cluster to be populated with Topology information and Class.
 	ClusterTopologyUnsafeUpdateClassNameAnnotation = "unsafe.topology.cluster.x-k8s.io/disable-update-class-name-check"
 
+	// MachinePoolOwnedLabel is the label set on Machines and InfraMachines linked to a MachinePool.
+	MachinePoolOwnedLabel = "machinepool.cluster.x-k8s.io/owned"
+
+	// FallbackMachineLabel indicates that a Machine belongs to a MachinePool that does not support MachinePool Machines.
+	// As such, these Machines exist to create a consistent user experience and will not have an infrastructure reference. The user will
+	// also be prevented from deleting these Machines.
+	FallbackMachineLabel = "machinepool.cluster.x-k8s.io/fallback-machine"
+
+	// AllowFallbackMachineDeletionAnnotation is used to bypass the prevention of deletion of fallback machines. The controller will
+	// apply this annotation before deletion.
+	AllowFallbackMachineDeletionAnnotation = "machinepool.cluster.x-k8s.io/allow-fallback-deletion"
+
 	// ProviderNameLabel is the label set on components in the provider manifest.
 	// This label allows to easily identify all the components belonging to a provider; the clusterctl
 	// tool uses this label for implementing provider's lifecycle operations.

api/v1beta1/machine_webhook.go

@@ -39,8 +39,8 @@ func (m *Machine) SetupWebhookWithManager(mgr ctrl.Manager) error {
 		Complete()
 }
 
-// +kubebuilder:webhook:verbs=create;update,path=/validate-cluster-x-k8s-io-v1beta1-machine,mutating=false,failurePolicy=fail,matchPolicy=Equivalent,groups=cluster.x-k8s.io,resources=machines,versions=v1beta1,name=validation.machine.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1
-// +kubebuilder:webhook:verbs=create;update,path=/mutate-cluster-x-k8s-io-v1beta1-machine,mutating=true,failurePolicy=fail,matchPolicy=Equivalent,groups=cluster.x-k8s.io,resources=machines,versions=v1beta1,name=default.machine.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1
+// +kubebuilder:webhook:verbs=create;update;delete,path=/validate-cluster-x-k8s-io-v1beta1-machine,mutating=false,failurePolicy=fail,matchPolicy=Equivalent,groups=cluster.x-k8s.io,resources=machines,versions=v1beta1,name=validation.machine.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1
+// +kubebuilder:webhook:verbs=create;update;delete,path=/mutate-cluster-x-k8s-io-v1beta1-machine,mutating=true,failurePolicy=fail,matchPolicy=Equivalent,groups=cluster.x-k8s.io,resources=machines,versions=v1beta1,name=default.machine.cluster.x-k8s.io,sideEffects=None,admissionReviewVersions=v1;v1beta1
 
 var _ webhook.Validator = &Machine{}
 var _ webhook.Defaulter = &Machine{}
@@ -57,7 +57,10 @@ func (m *Machine) Default() {
 	}
 
 	if m.Spec.InfrastructureRef.Namespace == "" {
-		m.Spec.InfrastructureRef.Namespace = m.Namespace
+		// Don't autofill namespace for MachinePool Machines since the infraRef will be populated by the MachinePool controller.
+		if _, isMachinePoolMachine := m.Labels[MachinePoolOwnedLabel]; !isMachinePoolMachine {
+			m.Spec.InfrastructureRef.Namespace = m.Namespace
+		}
 	}
 
 	if m.Spec.Version != nil && !strings.HasPrefix(*m.Spec.Version, "v") {
@@ -86,20 +89,29 @@ func (m *Machine) ValidateUpdate(old runtime.Object) error {
 
 // ValidateDelete implements webhook.Validator so a webhook will be registered for the type.
 func (m *Machine) ValidateDelete() error {
+	if _, isFallbackMachine := m.Labels[FallbackMachineLabel]; isFallbackMachine {
+		if _, allowDelete := m.Annotations[AllowFallbackMachineDeletionAnnotation]; !allowDelete {
+			return apierrors.NewBadRequest("fallback MachinePool Machine cannot be deleted by user")
+		}
+	}
+
 	return nil
 }
 
 func (m *Machine) validate(old *Machine) error {
 	var allErrs field.ErrorList
 	specPath := field.NewPath("spec")
 	if m.Spec.Bootstrap.ConfigRef == nil && m.Spec.Bootstrap.DataSecretName == nil {
-		allErrs = append(
-			allErrs,
-			field.Required(
-				specPath.Child("bootstrap", "data"),
-				"expected either spec.bootstrap.dataSecretName or spec.bootstrap.configRef to be populated",
-			),
-		)
+		// MachinePool Machines don't have a bootstrap configRef, so don't require it. The bootstrap config is instead owned by the MachinePool.
+		if _, isMachinePoolMachine := m.Labels[MachinePoolOwnedLabel]; !isMachinePoolMachine {
+			allErrs = append(
+				allErrs,
+				field.Required(
+					specPath.Child("bootstrap", "data"),
+					"expected either spec.bootstrap.dataSecretName or spec.bootstrap.configRef to be populated",
+				),
+			)
+		}
 	}
 
 	if m.Spec.Bootstrap.ConfigRef != nil && m.Spec.Bootstrap.ConfigRef.Namespace != m.Namespace {
@@ -113,15 +125,17 @@ func (m *Machine) validate(old *Machine) error {
 		)
 	}
 
-	if m.Spec.InfrastructureRef.Namespace != m.Namespace {
-		allErrs = append(
-			allErrs,
-			field.Invalid(
-				specPath.Child("infrastructureRef", "namespace"),
-				m.Spec.InfrastructureRef.Namespace,
-				"must match metadata.namespace",
-			),
-		)
+	if _, isMachinePoolMachine := m.Labels[MachinePoolOwnedLabel]; !isMachinePoolMachine {
+		if m.Spec.InfrastructureRef.Namespace != m.Namespace {
+			allErrs = append(
+				allErrs,
+				field.Invalid(
+					specPath.Child("infrastructureRef", "namespace"),
+					m.Spec.InfrastructureRef.Namespace,
+					"must match metadata.namespace",
+				),
+			)
+		}
 	}
 
 	if old != nil && old.Spec.ClusterName != m.Spec.ClusterName {

cmd/clusterctl/client/tree/discovery.go

@@ -112,8 +112,10 @@ func Discovery(ctx context.Context, c client.Client, namespace, name string, opt
 				tree.Add(m, machineInfra, ObjectMetaName("MachineInfrastructure"), NoEcho(true))
 			}
 
-			if machineBootstrap, err := external.Get(ctx, c, m.Spec.Bootstrap.ConfigRef, cluster.Namespace); err == nil {
-				tree.Add(m, machineBootstrap, ObjectMetaName("BootstrapConfig"), NoEcho(true))
+			if m.Spec.Bootstrap.ConfigRef != nil {
+				if machineBootstrap, err := external.Get(ctx, c, m.Spec.Bootstrap.ConfigRef, cluster.Namespace); err == nil {
+					tree.Add(m, machineBootstrap, ObjectMetaName("BootstrapConfig"), NoEcho(true))
+				}
 			}
 		}
 	}
@@ -141,25 +143,25 @@ func Discovery(ctx context.Context, c client.Client, namespace, name string, opt
 		if err != nil {
 			return nil, err
 		}
-
-		// Handles orphan machines.
-		if len(machineMap) < len(machinesList.Items) {
-			other := VirtualObject(cluster.Namespace, "OtherGroup", "Other")
-			tree.Add(workers, other)
-
-			for i := range machinesList.Items {
-				m := &machinesList.Items[i]
-				if _, ok := machineMap[m.Name]; ok {
-					continue
-				}
-				addMachineFunc(other, m)
-			}
-		}
 	}
 
 	if len(machinePoolList.Items) > 0 { // Add MachinePool objects
 		tree.Add(cluster, workers)
-		addMachinePoolsToObjectTree(ctx, c, cluster.Namespace, workers, machinePoolList, tree)
+		addMachinePoolsToObjectTree(ctx, c, cluster.Namespace, workers, machinePoolList, machinesList, tree, addMachineFunc)
+	}
+
+	// Handles orphan machines.
+	if len(machineMap) < len(machinesList.Items) {
+		other := VirtualObject(cluster.Namespace, "OtherGroup", "Other")
+		tree.Add(workers, other)
+
+		for i := range machinesList.Items {
+			m := &machinesList.Items[i]
+			if _, ok := machineMap[m.Name]; ok {
+				continue
+			}
+			addMachineFunc(other, m)
+		}
 	}
 
 	return tree, nil
@@ -263,20 +265,26 @@ func addMachineDeploymentToObjectTree(ctx context.Context, c client.Client, clus
 	return nil
 }
 
-func addMachinePoolsToObjectTree(ctx context.Context, c client.Client, namespace string, workers *unstructured.Unstructured, machinePoolList *expv1.MachinePoolList, tree *ObjectTree) {
+func addMachinePoolsToObjectTree(ctx context.Context, c client.Client, namespace string, workers *unstructured.Unstructured, machinePoolList *expv1.MachinePoolList, machinesList *clusterv1.MachineList, tree *ObjectTree, addMachineFunc func(parent client.Object, m *clusterv1.Machine)) {
 	for i := range machinePoolList.Items {
 		mp := &machinePoolList.Items[i]
-		_, visible := tree.Add(workers, mp)
+		_, visible := tree.Add(workers, mp, GroupingObject(true))
 
 		if visible {
 			if machinePoolBootstrap, err := external.Get(ctx, c, mp.Spec.Template.Spec.Bootstrap.ConfigRef, namespace); err == nil {
 				tree.Add(mp, machinePoolBootstrap, ObjectMetaName("BootstrapConfig"), NoEcho(true))
 			}
 
 			if machinePoolInfra, err := external.Get(ctx, c, &mp.Spec.Template.Spec.InfrastructureRef, namespace); err == nil {
-				tree.Add(mp, machinePoolInfra, ObjectMetaName("MachineInfrastructure"), NoEcho(true))
+				tree.Add(mp, machinePoolInfra, ObjectMetaName("MachinePoolInfrastructure"), NoEcho(true))
 			}
 		}
+
+		machines := selectMachinesControlledBy(machinesList, mp)
+
+		for _, m := range machines {
+			addMachineFunc(mp, m)
+		}
 	}
 }
 

config/webhook/manifests.yaml

@@ -24,6 +24,7 @@ webhooks:
     operations:
     - CREATE
     - UPDATE
+    - DELETE
     resources:
     - machines
   sideEffects: None
@@ -229,6 +230,7 @@ webhooks:
     operations:
     - CREATE
     - UPDATE
+    - DELETE
     resources:
     - machines
   sideEffects: None

exp/api/v1beta1/machinepool_types.go

@@ -27,6 +27,10 @@ import (
 const (
 	// MachinePoolFinalizer is used to ensure deletion of dependencies (nodes, infra).
 	MachinePoolFinalizer = "machinepool.cluster.x-k8s.io"
+
+	// MachinePoolNameLabel is the label indicating the name of the MachinePool a Machine is controleld by.
+	// Note: The value of this label may be a hash if the MachinePool name is longer than 63 characters.
+	MachinePoolNameLabel = "cluster.x-k8s.io/pool-name"
 )
 
 // ANCHOR: MachinePoolSpec