fix: store one copy of HTTPRoute Extension Filters

internal/provider/kubernetes/filters.go

@@ -50,13 +50,12 @@
 	return resourceItems, nil
 }
 
-func (r *gatewayAPIReconciler) getHTTPRouteFilters(ctx context.Context) ([]egv1a1.HTTPRouteFilter, error) {
-	httpFilterList := new(egv1a1.HTTPRouteFilterList)
-	if err := r.client.List(ctx, httpFilterList); err != nil {
-		return nil, fmt.Errorf("failed to list HTTPRouteFilters: %w", err)
+func (r *gatewayAPIReconciler) getHTTPRouteFilter(ctx context.Context, name, namespace string) (*egv1a1.HTTPRouteFilter, error) {
+	hrf := new(egv1a1.HTTPRouteFilter)
+	if err := r.client.Get(ctx, types.NamespacedName{Namespace: namespace, Name: name}, hrf); err != nil {
+		return nil, fmt.Errorf("failed to get HTTPRouteFilter: %w", err)
 	}
-
-	return httpFilterList.Items, nil
+	return hrf, nil
 }
 
 // processRouteFilterConfigMapRef adds the referenced ConfigMap in a HTTPRouteFilter

internal/provider/kubernetes/resource.go

@@ -10,7 +10,6 @@ import (
 	"k8s.io/apimachinery/pkg/util/sets"
 	gwapiv1 "sigs.k8s.io/gateway-api/apis/v1"
 
-	egv1a1 "github.com/envoyproxy/gateway/api/v1alpha1"
 	"github.com/envoyproxy/gateway/internal/utils"
 )
 
@@ -61,35 +60,35 @@ type resourceMappings struct {
 	// The key is the namespaced name, group and kind of the filter and the value is the
 	// unstructured form of the resource.
 	extensionRefFilters map[utils.NamespacedNameWithGroupKind]unstructured.Unstructured
-	// httpRouteFilters is a map of HTTPRouteFilters, where the key is the namespaced name,
-	// group and kind of the HTTPFilter.
-	httpRouteFilters map[utils.NamespacedNameWithGroupKind]*egv1a1.HTTPRouteFilter
+	// Set for storing HTTPRouteExtensions (Envoy Gateway or Custom) NamespacedNames referenced by various
+	// route rules objects.
+	allAssociatedHTTPRouteExtensionFilters sets.Set[utils.NamespacedNameWithGroupKind]
 }
 
 func newResourceMapping() *resourceMappings {
 	return &resourceMappings{
-		allAssociatedGateways:               sets.New[string](),
-		allAssociatedReferenceGrants:        sets.New[string](),
-		allAssociatedServiceImports:         sets.New[string](),
-		allAssociatedEndpointSlices:         sets.New[string](),
-		allAssociatedBackends:               sets.New[string](),
-		allAssociatedSecrets:                sets.New[string](),
-		allAssociatedConfigMaps:             sets.New[string](),
-		allAssociatedNamespaces:             sets.New[string](),
-		allAssociatedEnvoyProxies:           sets.New[string](),
-		allAssociatedEnvoyPatchPolicies:     sets.New[string](),
-		allAssociatedTLSRoutes:              sets.New[string](),
-		allAssociatedHTTPRoutes:             sets.New[string](),
-		allAssociatedGRPCRoutes:             sets.New[string](),
-		allAssociatedTCPRoutes:              sets.New[string](),
-		allAssociatedUDPRoutes:              sets.New[string](),
-		allAssociatedBackendRefs:            sets.New[gwapiv1.BackendObjectReference](),
-		allAssociatedClientTrafficPolicies:  sets.New[string](),
-		allAssociatedBackendTrafficPolicies: sets.New[string](),
-		allAssociatedSecurityPolicies:       sets.New[string](),
-		allAssociatedBackendTLSPolicies:     sets.New[string](),
-		allAssociatedEnvoyExtensionPolicies: sets.New[string](),
-		extensionRefFilters:                 map[utils.NamespacedNameWithGroupKind]unstructured.Unstructured{},
-		httpRouteFilters:                    map[utils.NamespacedNameWithGroupKind]*egv1a1.HTTPRouteFilter{},
+		allAssociatedGateways:                  sets.New[string](),
+		allAssociatedReferenceGrants:           sets.New[string](),
+		allAssociatedServiceImports:            sets.New[string](),
+		allAssociatedEndpointSlices:            sets.New[string](),
+		allAssociatedBackends:                  sets.New[string](),
+		allAssociatedSecrets:                   sets.New[string](),
+		allAssociatedConfigMaps:                sets.New[string](),
+		allAssociatedNamespaces:                sets.New[string](),
+		allAssociatedEnvoyProxies:              sets.New[string](),
+		allAssociatedEnvoyPatchPolicies:        sets.New[string](),
+		allAssociatedTLSRoutes:                 sets.New[string](),
+		allAssociatedHTTPRoutes:                sets.New[string](),
+		allAssociatedGRPCRoutes:                sets.New[string](),
+		allAssociatedTCPRoutes:                 sets.New[string](),
+		allAssociatedUDPRoutes:                 sets.New[string](),
+		allAssociatedBackendRefs:               sets.New[gwapiv1.BackendObjectReference](),
+		allAssociatedClientTrafficPolicies:     sets.New[string](),
+		allAssociatedBackendTrafficPolicies:    sets.New[string](),
+		allAssociatedSecurityPolicies:          sets.New[string](),
+		allAssociatedBackendTLSPolicies:        sets.New[string](),
+		allAssociatedEnvoyExtensionPolicies:    sets.New[string](),
+		extensionRefFilters:                    map[utils.NamespacedNameWithGroupKind]unstructured.Unstructured{},
+		allAssociatedHTTPRouteExtensionFilters: sets.New[utils.NamespacedNameWithGroupKind](),
 	}
 }

internal/provider/kubernetes/routes.go

@@ -238,18 +238,6 @@
 	resourceMap *resourceMappings, resourceTree *resource.Resources,
 ) error {
 	httpRouteList := &gwapiv1.HTTPRouteList{}
-	if r.hrfCRDExists {
-		httpFilters, err := r.getHTTPRouteFilters(ctx)
-		if err != nil {
-			return err
-		}
-
-		for i := range httpFilters {
-			filter := httpFilters[i]
-			resourceMap.httpRouteFilters[utils.GetNamespacedNameWithGroupKind(&filter)] = &filter
-			r.processRouteFilterConfigMapRef(ctx, &filter, resourceMap, resourceTree)
-		}
-	}
 
 	extensionRefFilters, err := r.getExtensionRefFilters(ctx)
 	if err != nil {
@@ -416,12 +404,18 @@
 
 					switch string(filter.ExtensionRef.Kind) {
 					case egv1a1.KindHTTPRouteFilter:
-						httpFilter, ok := resourceMap.httpRouteFilters[key]
-						if !ok {
-							r.log.Error(err, "HTTPRouteFilters not found; bypassing rule", "index", i)
-							continue
+						if r.hrfCRDExists {
+							httpFilter, err := r.getHTTPRouteFilter(ctx, key.Name, key.Namespace)
+							if err != nil {
+								r.log.Error(err, "HTTPRouteFilters not found; bypassing rule", "index", i)
+								continue
+							}
+							if !resourceMap.allAssociatedHTTPRouteExtensionFilters.Has(key) {
+								r.processRouteFilterConfigMapRef(ctx, httpFilter, resourceMap, resourceTree)
+								resourceMap.allAssociatedHTTPRouteExtensionFilters.Insert(key)
+								resourceTree.HTTPRouteFilters = append(resourceTree.HTTPRouteFilters, httpFilter)
+							}
 						}
-						resourceTree.HTTPRouteFilters = append(resourceTree.HTTPRouteFilters, httpFilter)
 					default:
 						extRefFilter, ok := resourceMap.extensionRefFilters[key]
 						if !ok {
@@ -433,7 +427,10 @@
 							continue
 						}
 
-						resourceTree.ExtensionRefFilters = append(resourceTree.ExtensionRefFilters, extRefFilter)
+						if !resourceMap.allAssociatedHTTPRouteExtensionFilters.Has(key) {
+							resourceMap.allAssociatedHTTPRouteExtensionFilters.Insert(key)
+							resourceTree.ExtensionRefFilters = append(resourceTree.ExtensionRefFilters, extRefFilter)
+						}
 					}
 				}
 			}