feat: filter out Gateways before reconciliation (#20)

Signed-off-by: Rahul-D78 <[email protected]>

controllers/gateway_controller.go

@@ -5,16 +5,19 @@ import (
 	"fmt"
 	"reflect"
 
+	"github.com/go-logr/logr"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/utils/pointer"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/builder"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/controller-runtime/pkg/handler"
 	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 	"sigs.k8s.io/controller-runtime/pkg/source"
 	gatewayv1beta1 "sigs.k8s.io/gateway-api/apis/v1beta1"
@@ -36,18 +39,37 @@ const gatewayServiceLabel = "konghq.com/owned-by-gateway"
 type GatewayReconciler struct {
 	client.Client
 	Scheme *runtime.Scheme
+	Log    logr.Logger
 }
 
 func (r *GatewayReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewControllerManagedBy(mgr).
-		For(&gatewayv1beta1.Gateway{}).
+		For(&gatewayv1beta1.Gateway{},
+			builder.WithPredicates(predicate.NewPredicateFuncs(r.gatewayHasMatchingGatewayClass)),
+		).
 		Watches(
 			&source.Kind{Type: &corev1.Service{}},
 			handler.EnqueueRequestsFromMapFunc(mapServiceToGateway),
 		).
 		Complete(r)
 }
 
+func (r *GatewayReconciler) gatewayHasMatchingGatewayClass(obj client.Object) bool {
+	gateway, ok := obj.(*gatewayv1beta1.Gateway)
+	if !ok {
+		r.Log.Error(fmt.Errorf("unexpected object type in gateway watch predicates"), "expected", "*gatewayv1beta1.Gateway", "found", reflect.TypeOf(obj))
+		return false
+	}
+	gatewayClass := &gatewayv1beta1.GatewayClass{}
+	if err := r.Client.Get(context.Background(), client.ObjectKey{Name: string(gateway.Spec.GatewayClassName)}, gatewayClass); err != nil {
+		if errors.IsNotFound(err) {
+			r.Log.Error(err, "gatewayclass not found", "gatewayclass", gateway.Spec.GatewayClassName)
+		}
+		return false
+	}
+	return true // some other problem retrieving the object, enqueue anyway to avoid dropping
+}
+
 func (r *GatewayReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
 	log := log.FromContext(ctx)