fix : Add Groups filter to CustomResourceDefinition reconciler

- Introduced Groups field in Options to specify API groups for CRDs.
- Implemented GroupPredicate to filter CRDs based on specified groups.
- Updated Setup function to apply the Groups filter during reconciliation.

Author: SatabdiG

pkg/controller/options.go

@@ -77,6 +77,11 @@ type Options struct {
 
 	// EventFilterFunctions used to filter events emitted by the controllers.
 	EventFilterFunctions []event.FilterFn
+
+	// Groups is the list of API groups managed by this provider.
+	// If specified, the CRD gate will only watch CRDs belonging to these groups,
+	// reducing unnecessary reconciles from unrelated CRDs in the cluster.
+	Groups []string
 }
 
 // ForControllerRuntime extracts options for controller-runtime.

pkg/reconciler/customresourcesgate/reconciler_test.go

@@ -23,10 +23,13 @@ import (
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
+	corev1 "k8s.io/api/core/v1"
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/event"
 
 	"github.com/crossplane/crossplane-runtime/v2/pkg/logging"
 	"github.com/crossplane/crossplane-runtime/v2/pkg/test"
@@ -560,3 +563,85 @@ func TestReconcile(t *testing.T) {
 		})
 	}
 }
+
+func TestGroupPredicate(t *testing.T) {
+	type args struct {
+		groups []string
+		obj    client.Object
+	}
+	type want struct {
+		match bool
+	}
+
+	cases := map[string]struct {
+		reason string
+		args   args
+		want   want
+	}{
+		"CRDGroupPresent": {
+			reason: "CRD is present in the specified groups, predicate should return true",
+			args: args{
+				groups: []string{"example.com"},
+				obj: &apiextensionsv1.CustomResourceDefinition{
+					Spec: apiextensionsv1.CustomResourceDefinitionSpec{
+						Group: "example.com",
+					},
+				},
+			},
+			want: want{
+				match: true,
+			},
+		},
+		"CRDGroupAbsent": {
+			reason: "CRD is not present in the specified groups, predicate should return false",
+			args: args{
+				groups: []string{"example.com"},
+				obj: &apiextensionsv1.CustomResourceDefinition{
+					Spec: apiextensionsv1.CustomResourceDefinitionSpec{
+						Group: "other.com",
+					},
+				},
+			},
+			want: want{
+				match: false,
+			},
+		},
+		"EmptyGroups": {
+			reason: "No groups specified, predicate should return false for any CRD",
+			args: args{
+				groups: []string{},
+				obj: &apiextensionsv1.CustomResourceDefinition{
+					Spec: apiextensionsv1.CustomResourceDefinitionSpec{
+						Group: "example.com",
+					},
+				},
+			},
+			want: want{
+				match: false,
+			},
+		},
+		"NonCRDObject": {
+			reason: "Object is not a CRD, predicate should return false",
+			args: args{
+				groups: []string{"example.com"},
+				obj:    &corev1.ConfigMap{},
+			},
+			want: want{
+				match: false,
+			},
+		},
+	}
+
+	for name, tc := range cases {
+		t.Run(name, func(t *testing.T) {
+			got := GroupPredicate(tc.args.groups...)
+			ev := event.GenericEvent{
+				Object: tc.args.obj,
+			}
+			match := got.Generic(ev)
+			if match != tc.want.match {
+				t.Errorf("\n%s\nGroupPredicate(...): -want match, +got match:\n%s", tc.reason, cmp.Diff(tc.want.match, match))
+			}
+		})
+	}
+}

pkg/reconciler/customresourcesgate/setup.go

@@ -22,6 +22,8 @@ import (
 
 	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/predicate"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 
 	"github.com/crossplane/crossplane-runtime/v2/pkg/controller"
@@ -38,9 +40,29 @@ func Setup(mgr ctrl.Manager, o controller.Options) error {
 		log:  o.Logger,
 		gate: o.Gate,
 	}
-
-	return ctrl.NewControllerManagedBy(mgr).
+	b := ctrl.NewControllerManagedBy(mgr).
 		For(&apiextensionsv1.CustomResourceDefinition{}).
-		Named("crd-gate").
-		Complete(reconcile.AsReconciler[*apiextensionsv1.CustomResourceDefinition](mgr.GetClient(), r))
+		Named("crd-gate")
+
+	if len(o.Groups) > 0 {
+		b = b.WithEventFilter(GroupPredicate(o.Groups...))
+	}
+
+	return b.Complete(reconcile.AsReconciler[*apiextensionsv1.CustomResourceDefinition](mgr.GetClient(), r))
+}
+
+// GroupPredicate returns a predicate that filters CustomResourceDefinitions by group.
+func GroupPredicate(groups ...string) predicate.Predicate {
+	groupSet := make(map[string]struct{})
+	for _, g := range groups {
+		groupSet[g] = struct{}{}
+	}
+	return predicate.NewPredicateFuncs(func(obj client.Object) bool {
+		crd, ok := obj.(*apiextensionsv1.CustomResourceDefinition)
+		if !ok {
+			return false
+		}
+		_, ok = groupSet[crd.Spec.Group]
+		return ok
+	})
 }