Refactor DesignateWorker controller to use generic helper functions

- Extract findWorkerListObjects to return ObjectMeta instead of full objects
- Create generic createRequestsFromObjectUpdates helper function
- Add requestsForObjectUpdates method for cleaner watch setup
- Refactor existing findObjectsForSrc to use new helper
- Add comprehensive godoc comments to all new functions
- Add TODO/NOTE comments for future validation and enhancement work

This reduces code duplication and improves memory efficiency by only
keeping ObjectMeta for reconcile requests. The pattern can be extended
to other controllers in the operator.

Author: beagles

api/v1beta1/designate_webhook.go

@@ -128,6 +128,11 @@ func (r *Designate) ValidateCreate() (admission.Warnings, error) {
 		allErrs = append(allErrs, err...)
 	}
 
+	// NOTE(beagles): validator here and for updates about
+	// - nsRecords ending with period
+	// - the same not mentioned multiple times for different priorities.
+	// - check expected names in service overrides (maybe just check camel case)
+	//
 	if len(allErrs) != 0 {
 		return nil, apierrors.NewInvalid(
 			schema.GroupKind{Group: "designate.openstack.org", Kind: "Designate"},

controllers/designateunbound_controller.go

@@ -553,6 +553,7 @@ func stubZoneDefaults(values map[string]string) map[string]string {
 // return the expected defaults defined in the build.
 // TODO(beagles): it might be a good idea to have this settable through an environment variable to bridge
 // unexpected compatibility issues.
+// NOTE(beagles): we should also consider adding the cidr for the cluster network.
 func (r *UnboundReconciler) getClusterJoinSubnets(ctx context.Context) []string {
 	Log := r.GetLogger(ctx)
 

controllers/designateworker_controller.go

@@ -54,6 +54,7 @@ import (
 	"github.com/openstack-k8s-operators/lib-common/modules/common/tls"
 	"github.com/openstack-k8s-operators/lib-common/modules/common/util"
 	mariadbv1 "github.com/openstack-k8s-operators/mariadb-operator/api/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 // GetClient -
@@ -338,7 +339,7 @@ func (r *DesignateWorkerReconciler) SetupWithManager(ctx context.Context, mgr ct
 			handler.EnqueueRequestsFromMapFunc(svcSecretFn)).
 		Watches(
 			&corev1.Secret{},
-			handler.EnqueueRequestsFromMapFunc(r.findObjectsForSrc),
+			handler.EnqueueRequestsFromMapFunc(r.requestsForObjectUpdates),
 			builder.WithPredicates(predicate.ResourceVersionChangedPredicate{}),
 		).
 		// watch the config CMs we don't own
@@ -350,6 +351,71 @@ func (r *DesignateWorkerReconciler) SetupWithManager(ctx context.Context, mgr ct
 		Complete(r)
 }
 
+// findObjectFunc is a function type for listing objects that match a given field selector.
+// It returns a slice of ObjectMeta for the matching objects, allowing callers to create
+// reconcile requests without needing full object details.
+type findObjectFunc func(ctx context.Context, cl client.Client, field string, src client.Object, log *logr.Logger) ([]metav1.ObjectMeta, error)
+
+// findWorkerListObjects finds all DesignateWorker objects that reference the given source object
+// through a specific field. It returns only the ObjectMeta for matched objects to minimize memory usage.
+func findWorkerListObjects(ctx context.Context, cl client.Client, field string, src client.Object, log *logr.Logger) ([]metav1.ObjectMeta, error) {
+	crList := &designatev1beta1.DesignateWorkerList{}
+	err := cl.List(ctx, crList, &client.ListOptions{
+		FieldSelector: fields.OneTermEqualSelector(field, src.GetName()),
+		Namespace:     src.GetNamespace(),
+	})
+	if err != nil {
+		log.Error(err, fmt.Sprintf("listing %s for field: %s - %s", crList.GroupVersionKind().Kind, field, src.GetNamespace()))
+		return []metav1.ObjectMeta{}, err
+	}
+	items := make([]metav1.ObjectMeta, len(crList.Items))
+	for i, item := range crList.Items {
+		items[i] = item.ObjectMeta
+	}
+	return items, nil
+}
+
+// createRequestsFromObjectUpdates is a generic helper function that creates reconcile requests
+// for all objects that reference a given source object. It iterates through configured watch fields
+// and uses the provided findObjectFunc to locate dependent objects.
+// This function encapsulates the boilerplate pattern used across multiple controllers to handle
+// changes in watched resources (secrets, configmaps, topology, etc.).
+func createRequestsFromObjectUpdates(ctx context.Context, cl client.Client, src client.Object, fn findObjectFunc, log *logr.Logger) []reconcile.Request {
+	allWatchFields := []string{
+		passwordSecretField,
+		caBundleSecretNameField,
+		topologyField,
+	}
+	requests := []reconcile.Request{}
+	for _, field := range allWatchFields {
+		objs, err := fn(ctx, cl, field, src, log)
+		if err != nil {
+			return requests
+		}
+		for _, obj := range objs {
+			log.Info(fmt.Sprintf("input source %s changed, reconcile: %s - %s", src.GetName(), obj.GetName(), obj.GetNamespace()))
+			requests = append(requests,
+				reconcile.Request{
+					NamespacedName: types.NamespacedName{
+						Name:      obj.GetName(),
+						Namespace: obj.GetNamespace(),
+					},
+				},
+			)
+		}
+	}
+
+	return requests
+}
+
+// requestsForObjectUpdates creates reconcile requests for DesignateWorker objects that depend on
+// the given source object (e.g., a Secret or Topology). This method is used as a handler function
+// in the controller's watch setup.
+func (r *DesignateWorkerReconciler) requestsForObjectUpdates(ctx context.Context, src client.Object) []reconcile.Request {
+	Log := r.GetLogger(ctx)
+	return createRequestsFromObjectUpdates(ctx, r.Client, src, findWorkerListObjects, &Log)
+}
+
 func (r *DesignateWorkerReconciler) findObjectsForSrc(ctx context.Context, src client.Object) []reconcile.Request {
 	requests := []reconcile.Request{}
 
@@ -362,25 +428,17 @@ func (r *DesignateWorkerReconciler) findObjectsForSrc(ctx context.Context, src c
 	}
 
 	for _, field := range allWatchFields {
-		crList := &designatev1beta1.DesignateWorkerList{}
-		listOps := &client.ListOptions{
-			FieldSelector: fields.OneTermEqualSelector(field, src.GetName()),
-			Namespace:     src.GetNamespace(),
-		}
-		err := r.List(context.TODO(), crList, listOps)
+		objs, err := findWorkerListObjects(ctx, r.Client, field, src, &Log)
 		if err != nil {
-			Log.Error(err, fmt.Sprintf("listing %s for field: %s - %s", crList.GroupVersionKind().Kind, field, src.GetNamespace()))
 			return requests
 		}
-
-		for _, item := range crList.Items {
-			Log.Info(fmt.Sprintf("input source %s changed, reconcile: %s - %s", src.GetName(), item.GetName(), item.GetNamespace()))
-
+		for _, obj := range objs {
+			Log.Info(fmt.Sprintf("input source %s changed, reconcile: %s - %s", src.GetName(), obj.GetName(), obj.GetNamespace()))
 			requests = append(requests,
 				reconcile.Request{
 					NamespacedName: types.NamespacedName{
-						Name:      item.GetName(),
-						Namespace: item.GetNamespace(),
+						Name:      obj.GetName(),
+						Namespace: obj.GetNamespace(),
 					},
 				},
 			)