fix: make creating DataPlanes index conditional on enabling the Contr…

…olPlane controller (#103) (#106)

CHANGELOG.md

@@ -31,6 +31,10 @@
   autoscaling with `GatewayConfiguration` as the generated `DataPlane` deployment
   will no longer be rejected.
   [#79](https://github.com/Kong/gateway-operator/pull/79)
+- Make creating a `DataPlane` index conditional based on enabling the `ControlPlane`
+  controller. This allows running KGO without `ControlPlane` CRD with its controller
+  disabled.
+  [#103](https://github.com/Kong/gateway-operator/pull/103)
 
 ## [v1.2.1]
 

internal/utils/index/index.go

@@ -2,7 +2,9 @@ package index
 
 import (
 	"context"
+	"fmt"
 
+	"k8s.io/apimachinery/pkg/api/meta"
 	"sigs.k8s.io/controller-runtime/pkg/cache"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 
@@ -14,10 +16,17 @@ const (
 	DataPlaneNameIndex = "dataplane"
 )
 
-// IndexDataPlaneNameOnControlPlane indexes the ControlPlane .spec.dataplaneName field
+// DataPlaneNameOnControlPlane indexes the ControlPlane .spec.dataplaneName field
 // on the "dataplane" key.
-func IndexDataPlaneNameOnControlPlane(c cache.Cache) error {
-	return c.IndexField(context.Background(), &operatorv1beta1.ControlPlane{}, DataPlaneNameIndex, func(o client.Object) []string {
+func DataPlaneNameOnControlPlane(ctx context.Context, c cache.Cache) error {
+	if _, err := c.GetInformer(ctx, &operatorv1beta1.ControlPlane{}); err != nil {
+		if meta.IsNoMatchError(err) {
+			return nil
+		}
+		return fmt.Errorf("failed to get informer for v1beta1 ControlPlane: %w, disabling indexing DataPlanes for ControlPlanes' .spec.dataplaneName", err)
+	}
+
+	return c.IndexField(ctx, &operatorv1beta1.ControlPlane{}, DataPlaneNameIndex, func(o client.Object) []string {
 		controlPlane, ok := o.(*operatorv1beta1.ControlPlane)
 		if !ok {
 			return []string{}

modules/manager/controller_setup.go

@@ -1,6 +1,7 @@
 package manager
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"net/url"
@@ -93,8 +94,13 @@ func (c *ControllerDef) MaybeSetupWithManager(mgr ctrl.Manager) error {
 	return c.Controller.SetupWithManager(mgr)
 }
 
-func setupIndexes(mgr manager.Manager) error {
-	return index.IndexDataPlaneNameOnControlPlane(mgr.GetCache())
+func setupIndexes(ctx context.Context, mgr manager.Manager, cfg Config) error {
+	if cfg.ControlPlaneControllerEnabled || cfg.GatewayControllerEnabled {
+		if err := index.DataPlaneNameOnControlPlane(ctx, mgr.GetCache()); err != nil {
+			return fmt.Errorf("failed to setup index for DataPlane names on ControlPlane: %w", err)
+		}
+	}
+	return nil
 }
 
 // SetupControllers returns a list of ControllerDefs based on config.

modules/manager/run.go

@@ -186,7 +186,7 @@ func Run(
 		return fmt.Errorf("unable to start manager: %w", err)
 	}
 
-	if err := setupIndexes(mgr); err != nil {
+	if err := setupIndexes(context.Background(), mgr, cfg); err != nil {
 		return err
 	}