refactor: Use Patch instead of Update to set/remove finalizers

controllers/controller_shared.go

@@ -19,6 +19,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/meta"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/types"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/event"
 	"sigs.k8s.io/controller-runtime/pkg/predicate"
@@ -366,3 +367,56 @@ func getReferencedValue(ctx context.Context, cl client.Client, cr metav1.ObjectM
 		}
 	}
 }
+
+// Add finalizer through a MergePatch
+// Avoids updating the entire object and only changes the finalizers
+func addFinalizer(ctx context.Context, cl client.Client, cr client.Object) error {
+	crFinalizers := cr.GetFinalizers()
+
+	// Already exists, skip the update
+	if slices.Contains(crFinalizers, grafanaFinalizer) {
+		return nil
+	}
+
+	// Append finalizer and create patch
+	crFinalizers = append(crFinalizers, grafanaFinalizer)
+	patch, err := json.Marshal(map[string]interface{}{"metadata": map[string]interface{}{"finalizers": crFinalizers}})
+	if err != nil {
+		return err
+	}
+	return cl.Patch(ctx, cr, client.RawPatch(types.MergePatchType, patch))
+}
+
+// Remove finalizer through a MergePatch
+// Avoids updating the entire object and only changes the finalizers
+func removeFinalizer(ctx context.Context, cl client.Client, cr client.Object) error {
+	crFinalizers := cr.GetFinalizers()
+	length := len(crFinalizers)
+
+	// Skip patching if finalizers is empty
+	if length == 0 {
+		return nil
+	}
+
+	// Shift items in array if it contains and is not equal to grafanaFinalizer
+	index := 0
+	for i := 0; i < length; i++ {
+		if crFinalizers[i] == grafanaFinalizer {
+			continue
+		}
+		crFinalizers[index] = crFinalizers[i]
+		index++
+	}
+
+	// Skip patching if finalizer length is unchanged
+	if index == length {
+		return nil
+	}
+
+	// Create patch using slice
+	patch, err := json.Marshal(map[string]interface{}{"metadata": map[string]interface{}{"finalizers": crFinalizers[:index]}})
+	if err != nil {
+		return err
+	}
+	return cl.Patch(ctx, cr, client.RawPatch(types.MergePatchType, patch))
+}

controllers/grafanaalertrulegroup_controller.go

@@ -76,16 +76,13 @@ func (r *GrafanaAlertRuleGroupReconciler) Reconcile(ctx context.Context, req ctr
 	}
 
 	if group.GetDeletionTimestamp() != nil {
+		// Check if resource needs clean up
 		if controllerutil.ContainsFinalizer(group, grafanaFinalizer) {
-			// still need to clean up
-			err := r.finalize(ctx, group)
-			if err != nil {
-				return ctrl.Result{}, fmt.Errorf("cleaning up alert rule group: %w", err)
+			if err := r.finalize(ctx, group); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to finalize GrafanaAlertRuleGroup: %w", err)
 			}
-			controllerutil.RemoveFinalizer(group, grafanaFinalizer)
-			if err := r.Update(ctx, group); err != nil {
-				r.Log.Error(err, "failed to remove finalizer")
-				return ctrl.Result{}, err
+			if err := removeFinalizer(ctx, r.Client, group); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to remove finalizer: %w", err)
 			}
 		}
 		return ctrl.Result{}, nil
@@ -96,12 +93,13 @@ func (r *GrafanaAlertRuleGroupReconciler) Reconcile(ctx context.Context, req ctr
 			r.Log.Error(err, "updating status")
 		}
 		if meta.IsStatusConditionTrue(group.Status.Conditions, conditionNoMatchingInstance) {
-			controllerutil.RemoveFinalizer(group, grafanaFinalizer)
+			if err := removeFinalizer(ctx, r.Client, group); err != nil {
+				r.Log.Error(err, "failed to remove finalizer")
+			}
 		} else {
-			controllerutil.AddFinalizer(group, grafanaFinalizer)
-		}
-		if err := r.Update(ctx, group); err != nil {
-			r.Log.Error(err, "failed to set finalizer")
+			if err := addFinalizer(ctx, r.Client, group); err != nil {
+				r.Log.Error(err, "failed to set finalizer")
+			}
 		}
 	}()
 

controllers/grafanacontactpoint_controller.go

@@ -82,15 +82,13 @@ func (r *GrafanaContactPointReconciler) Reconcile(ctx context.Context, req ctrl.
 	}
 
 	if contactPoint.GetDeletionTimestamp() != nil {
+		// Check if resource needs clean up
 		if controllerutil.ContainsFinalizer(contactPoint, grafanaFinalizer) {
-			err := r.finalize(ctx, contactPoint)
-			if err != nil {
-				return ctrl.Result{RequeueAfter: RequeueDelay}, fmt.Errorf("failed to finalize GrafanaContactPoint: %w", err)
+			if err := r.finalize(ctx, contactPoint); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to finalize GrafanaContactPoint: %w", err)
 			}
-			controllerutil.RemoveFinalizer(contactPoint, grafanaFinalizer)
-			if err := r.Update(ctx, contactPoint); err != nil {
-				r.Log.Error(err, "failed to remove finalizer")
-				return ctrl.Result{RequeueAfter: RequeueDelay}, fmt.Errorf("failed to update GrafanaContactPoint: %w", err)
+			if err := removeFinalizer(ctx, r.Client, contactPoint); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to remove finalizer: %w", err)
 			}
 		}
 		return ctrl.Result{}, nil
@@ -101,12 +99,13 @@ func (r *GrafanaContactPointReconciler) Reconcile(ctx context.Context, req ctrl.
 			r.Log.Error(err, "updating status")
 		}
 		if meta.IsStatusConditionTrue(contactPoint.Status.Conditions, conditionNoMatchingInstance) {
-			controllerutil.RemoveFinalizer(contactPoint, grafanaFinalizer)
+			if err := removeFinalizer(ctx, r.Client, contactPoint); err != nil {
+				r.Log.Error(err, "failed to remove finalizer")
+			}
 		} else {
-			controllerutil.AddFinalizer(contactPoint, grafanaFinalizer)
-		}
-		if err := r.Update(ctx, contactPoint); err != nil {
-			r.Log.Error(err, "failed to set finalizer")
+			if err := addFinalizer(ctx, r.Client, contactPoint); err != nil {
+				r.Log.Error(err, "failed to set finalizer")
+			}
 		}
 	}()
 

controllers/notificationpolicy_controller.go

@@ -80,15 +80,13 @@ func (r *GrafanaNotificationPolicyReconciler) Reconcile(ctx context.Context, req
 	}
 
 	if notificationPolicy.GetDeletionTimestamp() != nil {
+		// Check if resource needs clean up
 		if controllerutil.ContainsFinalizer(notificationPolicy, grafanaFinalizer) {
-			err := r.finalize(ctx, notificationPolicy)
-			if err != nil {
-				return ctrl.Result{RequeueAfter: RequeueDelay}, fmt.Errorf("failed to finalize GrafanaNotificationPolicy: %w", err)
+			if err := r.finalize(ctx, notificationPolicy); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to finalize GrafanaNotificationPolicy: %w", err)
 			}
-			controllerutil.RemoveFinalizer(notificationPolicy, grafanaFinalizer)
-			if err := r.Update(ctx, notificationPolicy); err != nil {
-				r.Log.Error(err, "failed to remove finalizer")
-				return ctrl.Result{RequeueAfter: RequeueDelay}, fmt.Errorf("failed to update GrafanaNotificationPolicy: %w", err)
+			if err := removeFinalizer(ctx, r.Client, notificationPolicy); err != nil {
+				return ctrl.Result{}, fmt.Errorf("failed to remove finalizer: %w", err)
 			}
 		}
 		return ctrl.Result{}, nil
@@ -99,12 +97,13 @@ func (r *GrafanaNotificationPolicyReconciler) Reconcile(ctx context.Context, req
 			r.Log.Error(err, "updating status")
 		}
 		if meta.IsStatusConditionTrue(notificationPolicy.Status.Conditions, conditionNoMatchingInstance) {
-			controllerutil.RemoveFinalizer(notificationPolicy, grafanaFinalizer)
+			if err := removeFinalizer(ctx, r.Client, notificationPolicy); err != nil {
+				r.Log.Error(err, "failed to remove finalizer")
+			}
 		} else {
-			controllerutil.AddFinalizer(notificationPolicy, grafanaFinalizer)
-		}
-		if err := r.Update(ctx, notificationPolicy); err != nil {
-			r.Log.Error(err, "failed to set finalizer")
+			if err := addFinalizer(ctx, r.Client, notificationPolicy); err != nil {
+				r.Log.Error(err, "failed to set finalizer")
+			}
 		}
 	}()