Refactor GatewayClass protection logic to use indexer

Simplify the GatewayClass deletion protection by leveraging an indexer to filter Gateways. This improves efficiency and readability by reducing unnecessary iterations and directly querying relevant resources.

Author: dspo

internal/controller/gatewayclass_congroller.go

@@ -17,6 +17,7 @@ import (
 	gatewayv1 "sigs.k8s.io/gateway-api/apis/v1"
 
 	"github.com/api7/api7-ingress-controller/internal/controller/config"
+	"github.com/api7/api7-ingress-controller/internal/controller/indexer"
 )
 
 const (
@@ -61,20 +62,18 @@ func (r *GatewayClassReconciler) Reconcile(ctx context.Context, req ctrl.Request
 	} else {
 		if controllerutil.ContainsFinalizer(gc, FinalizerGatewayClassProtection) {
 			var gatewayList gatewayv1.GatewayList
-			if err := r.List(ctx, &gatewayList); err != nil {
+			if err := r.List(ctx, &gatewayList, client.MatchingFields{indexer.GatewayClassIndexRef: gc.Name}); err != nil {
 				r.Log.Error(err, "failed to list gateways")
 				return ctrl.Result{}, err
 			}
-			var gateways []types.NamespacedName
-			for _, gateway := range gatewayList.Items {
-				if string(gateway.Spec.GatewayClassName) == gc.GetName() {
+			if len(gatewayList.Items) > 0 {
+				var gateways []types.NamespacedName
+				for _, item := range gatewayList.Items {
 					gateways = append(gateways, types.NamespacedName{
-						Namespace: gateway.GetNamespace(),
-						Name:      gateway.GetName(),
+						Namespace: item.GetNamespace(),
+						Name:      item.GetName(),
 					})
 				}
-			}
-			if len(gateways) > 0 {
 				r.Eventf(gc, "Warning", "DeletionBlocked", "the GatewayClass is still used by Gateways: %v", gateways)
 				return ctrl.Result{RequeueAfter: 5 * time.Second}, nil
 			} else {