Add Finalizers on LinodeCluster resource for each ControlPlane Linode…

…Machine resource (#434)

* add finalizers for control plane machines if using dns LB

cloud/scope/machine.go

@@ -6,8 +6,11 @@ import (
 	"fmt"
 
 	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/client-go/util/retry"
 	clusterv1 "sigs.k8s.io/cluster-api/api/v1beta1"
+	kutil "sigs.k8s.io/cluster-api/util"
 	"sigs.k8s.io/cluster-api/util/patch"
 	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
 
@@ -26,7 +29,8 @@ type MachineScopeParams struct {
 
 type MachineScope struct {
 	Client              K8sClient
-	PatchHelper         *patch.Helper
+	MachinePatchHelper  *patch.Helper
+	ClusterPatchHelper  *patch.Helper
 	Cluster             *clusterv1.Cluster
 	Machine             *clusterv1.Machine
 	LinodeClient        LinodeClient
@@ -111,14 +115,20 @@ func NewMachineScope(ctx context.Context, linodeClientConfig, dnsClientConfig Cl
 		return nil, fmt.Errorf("failed to create akamai dns client: %w", err)
 	}
 
-	helper, err := patch.NewHelper(params.LinodeMachine, params.Client)
+	machineHelper, err := patch.NewHelper(params.LinodeMachine, params.Client)
 	if err != nil {
-		return nil, fmt.Errorf("failed to init patch helper: %w", err)
+		return nil, fmt.Errorf("failed to init machine patch helper: %w", err)
+	}
+
+	clusterHelper, err := patch.NewHelper(params.LinodeCluster, params.Client)
+	if err != nil {
+		return nil, fmt.Errorf("failed to init cluster patch helper: %w", err)
 	}
 
 	return &MachineScope{
 		Client:              params.Client,
-		PatchHelper:         helper,
+		MachinePatchHelper:  machineHelper,
+		ClusterPatchHelper:  clusterHelper,
 		Cluster:             params.Cluster,
 		Machine:             params.Machine,
 		LinodeClient:        linodeClient,
@@ -129,21 +139,62 @@ func NewMachineScope(ctx context.Context, linodeClientConfig, dnsClientConfig Cl
 	}, nil
 }
 
-// PatchObject persists the machine configuration and status.
-func (s *MachineScope) PatchObject(ctx context.Context) error {
-	return s.PatchHelper.Patch(ctx, s.LinodeMachine)
+// CloseAll persists the linodemachine and linodecluster configuration and status.
+func (s *MachineScope) CloseAll(ctx context.Context) error {
+	if err := s.MachineClose(ctx); err != nil {
+		return err
+	}
+	if err := s.ClusterClose(ctx); err != nil {
+		return err
+	}
+	return nil
+}
+
+// MachineClose persists the linodemachine configuration and status.
+func (s *MachineScope) MachineClose(ctx context.Context) error {
+	return retry.OnError(retry.DefaultRetry, apierrors.IsConflict, func() error {
+		return s.MachinePatchHelper.Patch(ctx, s.LinodeMachine)
+	})
 }
 
-// Close closes the current scope persisting the machine configuration and status.
-func (s *MachineScope) Close(ctx context.Context) error {
-	return s.PatchObject(ctx)
+// ClusterClose persists the linodecluster configuration and status.
+func (s *MachineScope) ClusterClose(ctx context.Context) error {
+	return retry.OnError(retry.DefaultRetry, apierrors.IsConflict, func() error {
+		return s.ClusterPatchHelper.Patch(ctx, s.LinodeCluster)
+	})
 }
 
 // AddFinalizer adds a finalizer if not present and immediately patches the
 // object to avoid any race conditions.
 func (s *MachineScope) AddFinalizer(ctx context.Context) error {
 	if controllerutil.AddFinalizer(s.LinodeMachine, infrav1alpha2.MachineFinalizer) {
-		return s.Close(ctx)
+		return s.MachineClose(ctx)
+	}
+
+	return nil
+}
+
+// AddLinodeClusterFinalizer adds a finalizer if not present and immediately patches the
+// object to avoid any race conditions.
+func (s *MachineScope) AddLinodeClusterFinalizer(ctx context.Context) error {
+	if !kutil.IsControlPlaneMachine(s.Machine) {
+		return nil
+	}
+	if controllerutil.AddFinalizer(s.LinodeCluster, s.LinodeMachine.Name) {
+		return s.ClusterClose(ctx)
+	}
+
+	return nil
+}
+
+// RemoveLinodeClusterFinalizer adds a finalizer if not present and immediately patches the
+// object to avoid any race conditions.
+func (s *MachineScope) RemoveLinodeClusterFinalizer(ctx context.Context) error {
+	if !kutil.IsControlPlaneMachine(s.Machine) {
+		return nil
+	}
+	if controllerutil.RemoveFinalizer(s.LinodeCluster, s.LinodeMachine.Name) {
+		return s.ClusterClose(ctx)
 	}
 
 	return nil