[core] Use device label instead of field indexer in LLDP controller

Author: nikatza

internal/controller/core/lldp_controller.go

@@ -389,7 +389,7 @@ func (r *LLDPReconciler) validateUniqueLLDPPerDevice(ctx context.Context, s *lld
 	var list v1alpha1.LLDPList
 	if err := r.List(ctx, &list,
 		client.InNamespace(s.LLDP.Namespace),
-		client.MatchingFields{".spec.deviceRef.name": s.LLDP.Spec.DeviceRef.Name},
+		client.MatchingLabels{v1alpha1.DeviceLabel: s.Device.Name},
 	); err != nil {
 		return err
 	}
@@ -423,13 +423,6 @@ func (r *LLDPReconciler) SetupWithManager(ctx context.Context, mgr ctrl.Manager)
 		return fmt.Errorf("failed to create label selector predicate: %w", err)
 	}
 
-	if err := mgr.GetFieldIndexer().IndexField(ctx, &v1alpha1.LLDP{}, ".spec.deviceRef.name", func(obj client.Object) []string {
-		lldp := obj.(*v1alpha1.LLDP)
-		return []string{lldp.Spec.DeviceRef.Name}
-	}); err != nil {
-		return err
-	}
-
 	c := ctrl.NewControllerManagedBy(mgr).
 		For(&v1alpha1.LLDP{}).
 		Named("lldp").