✨Introduce NodeDeletionStrategy to allow drain node when deleting cluster

api/v1beta1/conversion.go

@@ -573,3 +573,8 @@ func Convert_v1beta1_Condition_To_v1_Condition(_ *Condition, _ *metav1.Condition
 	// NOTE: legacy (v1beta1) conditions should not be automatically converted into v1beta2 conditions.
 	return nil
 }
+
+// Convert_v1beta2_Topology_To_v1beta1_Topology is an autogenerated conversion function.
+func Convert_v1beta2_Topology_To_v1beta1_Topology(in *clusterv1.Topology, out *Topology, s apimachineryconversion.Scope) error {
+	return autoConvert_v1beta2_Topology_To_v1beta1_Topology(in, out, s)
+}

api/v1beta2/cluster_types.go

@@ -585,6 +585,15 @@ type Topology struct {
 	// +listMapKey=name
 	// +kubebuilder:validation:MaxItems=1000
 	Variables []ClusterVariable `json:"variables,omitempty"`
+
+	// nodeDeletionStrategy specifies the strategy to delete nodes in the cluster.
+	// Available options:
+	// - graceful
+	// - force
+	// By default it's "force".
+	// +optional
+	// +kubebuilder:validation:Enum=force;graceful
+	NodeDeletionStrategy *NodeDeletionStrategyType `json:"nodeDeletionStrategy,omitempty"`
 }
 
 // ControlPlaneTopology specifies the parameters for the control plane nodes in the cluster.
@@ -901,6 +910,16 @@ type MachinePoolVariables struct {
 	Overrides []ClusterVariable `json:"overrides,omitempty"`
 }
 
+// NodeDeletionStrategyType defines type of NodeDeletionStrategy.
+type NodeDeletionStrategyType string
+
+const (
+	// NodeDeletionStrategyForce defines a force type strategy that node will be deleted immediately without drain.
+	NodeDeletionStrategyForce NodeDeletionStrategyType = "force"
+	// NodeDeletionStrategyGracefulWithTimeout defines a force type strategy that node will be deleted with drain.
+	NodeDeletionStrategyGracefulWithTimeout NodeDeletionStrategyType = "gracefulWithTimeout"
+)
+
 // ANCHOR_END: ClusterSpec
 
 // ANCHOR: ClusterNetwork

internal/controllers/machine/machine_controller.go

@@ -714,8 +714,8 @@ func (r *Reconciler) nodeVolumeDetachTimeoutExceeded(machine *clusterv1.Machine)
 // and if the Machine is not the last control plane node in the cluster.
 func (r *Reconciler) isDeleteNodeAllowed(ctx context.Context, cluster *clusterv1.Cluster, machine *clusterv1.Machine) error {
 	log := ctrl.LoggerFrom(ctx)
-	// Return early if the cluster is being deleted.
-	if !cluster.DeletionTimestamp.IsZero() {
+	// Return early if the cluster is being deleted and cluster's nodeDeletionStrategy is not set or set to `force`.
+	if !cluster.DeletionTimestamp.IsZero() && (cluster.Spec.Topology == nil || cluster.Spec.Topology.NodeDeletionStrategy == nil || *cluster.Spec.Topology.NodeDeletionStrategy == clusterv1.NodeDeletionStrategyForce) {
 		return errClusterIsBeingDeleted
 	}
 

internal/controllers/machine/machine_controller_test.go

@@ -2664,10 +2664,66 @@ func TestIsDeleteNodeAllowed(t *testing.T) {
 					DeletionTimestamp: &deletionts,
 					Finalizers:        []string{clusterv1.ClusterFinalizer},
 				},
+				Spec: clusterv1.ClusterSpec{
+					Topology: &clusterv1.Topology{},
+				},
 			},
 			machine:       &clusterv1.Machine{},
 			expectedError: errClusterIsBeingDeleted,
 		},
+		{
+			name: "has nodeRef and cluster is being deleted, nodeDeletionStrategy set to force",
+			cluster: &clusterv1.Cluster{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:              "test-cluster",
+					Namespace:         metav1.NamespaceDefault,
+					DeletionTimestamp: &deletionts,
+					Finalizers:        []string{clusterv1.ClusterFinalizer},
+				},
+				Spec: clusterv1.ClusterSpec{
+					Topology: &clusterv1.Topology{
+						NodeDeletionStrategy: ptr.To(clusterv1.NodeDeletionStrategyForce),
+					},
+				},
+			},
+			machine:       &clusterv1.Machine{},
+			expectedError: errClusterIsBeingDeleted,
+		},
+		{
+			name: "has nodeRef and control plane is healthy, with nodeDeletionStrategy set to graceful",
+			cluster: &clusterv1.Cluster{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "test-cluster",
+					Namespace: metav1.NamespaceDefault,
+				},
+				Spec: clusterv1.ClusterSpec{
+					Topology: &clusterv1.Topology{
+						NodeDeletionStrategy: ptr.To(clusterv1.NodeDeletionStrategyForce),
+					},
+				},
+			},
+			machine: &clusterv1.Machine{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      "created",
+					Namespace: metav1.NamespaceDefault,
+					Labels: map[string]string{
+						clusterv1.ClusterNameLabel: "test-cluster",
+					},
+					Finalizers: []string{clusterv1.MachineFinalizer},
+				},
+				Spec: clusterv1.MachineSpec{
+					ClusterName:       "test-cluster",
+					InfrastructureRef: corev1.ObjectReference{},
+					Bootstrap:         clusterv1.Bootstrap{DataSecretName: ptr.To("data")},
+				},
+				Status: clusterv1.MachineStatus{
+					NodeRef: &corev1.ObjectReference{
+						Name: "test",
+					},
+				},
+			},
+			expectedError: nil,
+		},
 		{
 			name: "has nodeRef and control plane is healthy and externally managed",
 			cluster: &clusterv1.Cluster{