Use findObjectsForSrc to watch the referenced topology

With the goal of deduplicating the current code as much as possible and
help spreading the pattern across the operators, this patch adds the
topologyRef dynamic field to the existing glanceAPIWatchList. This
allows to both index the field (and use fieldSelector when the GlanceAPI
CR is retrieved), and remove the topologyFn/tpFn functions.
The watcher is now based on GenerationChangedPredicate, which only
triggers a reconcile when .Spec for the referenced topology changes.

Signed-off-by: Francesco Pantano <[email protected]>

controllers/glance_common.go

@@ -49,6 +49,7 @@ const (
 	caBundleSecretNameField = ".spec.tls.caBundleSecretName"
 	tlsAPIInternalField     = ".spec.tls.api.internal.secretName"
 	tlsAPIPublicField       = ".spec.tls.api.public.secretName"
+	topologyField           = ".spec.topologyRef.Name"
 )
 
 var (
@@ -60,6 +61,7 @@ var (
 		caBundleSecretNameField,
 		tlsAPIInternalField,
 		tlsAPIPublicField,
+		topologyField,
 	}
 )
 

controllers/glanceapi_controller.go

@@ -22,7 +22,6 @@ import (
 	"strings"
 
 	batchv1 "k8s.io/api/batch/v1"
-	"k8s.io/apimachinery/pkg/api/equality"
 	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/fields"
@@ -34,7 +33,6 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/builder"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/controller/controllerutil"
-	"sigs.k8s.io/controller-runtime/pkg/event"
 	"sigs.k8s.io/controller-runtime/pkg/handler"
 	"sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/controller-runtime/pkg/predicate"
@@ -246,6 +244,18 @@ func (r *GlanceAPIReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		return err
 	}
 
+	// index topologyField
+	if err := mgr.GetFieldIndexer().IndexField(context.Background(), &glancev1.GlanceAPI{}, topologyField, func(rawObj client.Object) []string {
+		// Extract the topology name from the spec, if one is provided
+		cr := rawObj.(*glancev1.GlanceAPI)
+		if cr.Spec.Topology == nil {
+			return nil
+		}
+		return []string{cr.Spec.Topology.Name}
+	}); err != nil {
+		return err
+	}
+
 	// Watch for changes to any CustomServiceConfigSecrets. Global secrets
 	svcSecretFn := func(_ context.Context, o client.Object) []reconcile.Request {
 		var namespace string = o.GetNamespace()
@@ -336,44 +346,6 @@ func (r *GlanceAPIReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		}
 		return nil
 	}
-	tpFn := predicate.Funcs{
-		UpdateFunc: func(e event.UpdateEvent) bool {
-			oldObj := e.ObjectOld.(*topologyv1.Topology)
-			newObj := e.ObjectNew.(*topologyv1.Topology)
-			// Compare spec
-			return !equality.Semantic.DeepEqual(oldObj.Spec, newObj.Spec)
-		},
-	}
-
-	topologyFn := func(_ context.Context, o client.Object) []reconcile.Request {
-		result := []reconcile.Request{}
-		// get all GlanceAPIs CRs
-		glanceAPIs := &glancev1.GlanceAPIList{}
-		listOpts := []client.ListOption{
-			client.InNamespace(o.GetNamespace()),
-		}
-		if err := r.Client.List(context.Background(), glanceAPIs, listOpts...); err != nil {
-			r.Log.Error(err, "Unable to retrieve GlanceAPI CRs %w")
-			return nil
-		}
-
-		for _, cr := range glanceAPIs.Items {
-			if cr.Spec.Topology != nil {
-				if o.GetName() == cr.Spec.Topology.Name {
-					name := client.ObjectKey{
-						Namespace: o.GetNamespace(),
-						Name:      cr.Name,
-					}
-					r.Log.Info(fmt.Sprintf("Topology %s is used by GlanceAPI CR %s", o.GetName(), cr.Name))
-					result = append(result, reconcile.Request{NamespacedName: name})
-				}
-			}
-		}
-		if len(result) > 0 {
-			return result
-		}
-		return nil
-	}
 
 	return ctrl.NewControllerManagedBy(mgr).
 		For(&glancev1.GlanceAPI{}).
@@ -393,8 +365,8 @@ func (r *GlanceAPIReconciler) SetupWithManager(mgr ctrl.Manager) error {
 		Watches(&memcachedv1.Memcached{},
 			handler.EnqueueRequestsFromMapFunc(memcachedFn)).
 		Watches(&topologyv1.Topology{},
-			handler.EnqueueRequestsFromMapFunc(topologyFn),
-			builder.WithPredicates(tpFn)).
+			handler.EnqueueRequestsFromMapFunc(r.findObjectsForSrc),
+			builder.WithPredicates(predicate.GenerationChangedPredicate{})).
 		Complete(r)
 }
 
@@ -857,7 +829,8 @@ func (r *GlanceAPIReconciler) reconcileNormal(
 	// When the Topology CR reference is updated and the current GlanceAPI
 	// switches to a new Topology, remove the finalizer from the previous
 	// Topology
-	if instance.Status.LastAppliedTopology != "" {
+	if instance.Spec.Topology == nil ||
+		(instance.Spec.Topology.Name != instance.Status.LastAppliedTopology) {
 		_, err = r.ensureDeletedTopology(ctx, instance, helper)
 		if err != nil {
 			return ctrl.Result{}, err
@@ -1564,19 +1537,21 @@ func (r *GlanceAPIReconciler) ensureDeletedTopology(
 ) (ctrl.Result, error) {
 	ns := instance.Namespace
 
-	// no Topology is currently passed to the GlanceAPI, and it was not used
-	// before
-	if instance.Spec.Topology == nil && instance.Status.LastAppliedTopology == "" {
+	// no Topology is passed to the GlanceAPI, and it was not used before
+	if instance.Status.LastAppliedTopology == "" {
 		return ctrl.Result{}, nil
 	}
+
+	// Topology is referenced in the .Spec, check the namespace
 	if instance.Spec.Topology != nil {
-		// Check namespace and set name
+		// Check namespace
 		if instance.Spec.Topology.Namespace != "" {
 			ns = instance.Spec.Topology.Namespace
 		}
 	}
 
 	name := instance.Status.LastAppliedTopology
+
 	// Remove the finalizer from the Topology CR
 	topology, _, err := topologyv1.GetTopologyByName(
 		ctx,
@@ -1597,7 +1572,7 @@ func (r *GlanceAPIReconciler) ensureDeletedTopology(
 			if err != nil && !k8s_errors.IsNotFound(err) {
 				return ctrl.Result{}, err
 			}
-			util.LogForObject(h, "Removed finalizer from Topology", instance)
+			util.LogForObject(h, "Removed finalizer from Topology", topology)
 		}
 	}
 	return ctrl.Result{}, err