Makes the TCPRoute controller optional (#10305)

Signed-off-by: Daneyon Hansen <[email protected]>

changelog/v1.18.0-beta34/issue_10304.yaml

@@ -0,0 +1,6 @@
+changelog:
+  - type: FIX
+    issueLink: https://github.com/solo-io/gloo/issues/10304
+    resolvesIssue: false
+    description: >-
+      Makes the Gateway API TCPRoute controller optional.

pkg/schemes/extended_scheme.go

@@ -0,0 +1,54 @@
+package schemes
+
+import (
+	"fmt"
+
+	"github.com/solo-io/gloo/projects/gateway2/wellknown"
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/rest"
+
+	gwv1a2 "sigs.k8s.io/gateway-api/apis/v1alpha2"
+)
+
+// AddGatewayV1A2Scheme adds the gwv1a2 scheme to the provided scheme if the TCPRoute CRD exists.
+func AddGatewayV1A2Scheme(restConfig *rest.Config, scheme *runtime.Scheme) error {
+	exists, err := CRDExists(restConfig, gwv1a2.GroupVersion.Group, gwv1a2.GroupVersion.Version, wellknown.TCPRouteKind)
+	if err != nil {
+		return fmt.Errorf("error checking if %s CRD exists: %w", wellknown.TCPRouteKind, err)
+	}
+
+	if exists {
+		if err := gwv1a2.Install(scheme); err != nil {
+			return fmt.Errorf("error adding Gateway API v1alpha2 to scheme: %w", err)
+		}
+	}
+
+	return nil
+}
+
+// Helper function to check if a CRD exists
+func CRDExists(restConfig *rest.Config, group, version, kind string) (bool, error) {
+	discoveryClient, err := discovery.NewDiscoveryClientForConfig(restConfig)
+	if err != nil {
+		return false, err
+	}
+
+	groupVersion := fmt.Sprintf("%s/%s", group, version)
+	apiResourceList, err := discoveryClient.ServerResourcesForGroupVersion(groupVersion)
+	if err != nil {
+		if discovery.IsGroupDiscoveryFailedError(err) || meta.IsNoMatchError(err) {
+			return false, nil
+		}
+		return false, err
+	}
+
+	for _, apiResource := range apiResourceList.APIResources {
+		if apiResource.Kind == kind {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}

pkg/schemes/scheme.go

@@ -1,6 +1,8 @@
 package schemes
 
 import (
+	"fmt"
+
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	discoveryv1 "k8s.io/api/discovery/v1"
@@ -23,7 +25,6 @@ import (
 var SchemeBuilder = runtime.SchemeBuilder{
 	// K8s Gateway API resources
 	gwv1.Install,
-	gwv1a2.Install,
 	gwv1b1.Install,
 
 	// Kubernetes Core resources
@@ -62,3 +63,12 @@ func DefaultScheme() *runtime.Scheme {
 	_ = AddToScheme(s)
 	return s
 }
+
+// TestingScheme unconditionally includes the default scheme and the gwv1a2 scheme (which includes TCPRoute).
+func TestingScheme() *runtime.Scheme {
+	s := DefaultScheme()
+	if err := gwv1a2.Install(s); err != nil {
+		panic(fmt.Sprintf("Failed to install gwv1a2 scheme: %v", err))
+	}
+	return s
+}

projects/gateway2/controller/controller.go

@@ -2,6 +2,7 @@ package controller
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	corev1 "k8s.io/api/core/v1"
@@ -56,6 +57,8 @@ type GatewayConfig struct {
 	Aws                     *deployer.AwsInfo
 
 	Extensions extensions.K8sGatewayExtensions
+	// CRDs defines the set of discovered Gateway API CRDs
+	CRDs sets.Set[string]
 }
 
 func NewBaseGatewayController(ctx context.Context, cfg GatewayConfig) error {
@@ -114,9 +117,26 @@ type controllerBuilder struct {
 }
 
 func (c *controllerBuilder) addIndexes(ctx context.Context) error {
-	return query.IterateIndices(func(obj client.Object, field string, indexer client.IndexerFunc) error {
-		return c.cfg.Mgr.GetFieldIndexer().IndexField(ctx, obj, field, indexer)
-	})
+	var errs []error
+
+	// Index for HTTPRoute
+	if err := c.cfg.Mgr.GetFieldIndexer().IndexField(ctx, &apiv1.HTTPRoute{}, query.HttpRouteTargetField, query.IndexerByObjType); err != nil {
+		errs = append(errs, err)
+	}
+
+	// Index for ReferenceGrant
+	if err := c.cfg.Mgr.GetFieldIndexer().IndexField(ctx, &apiv1beta1.ReferenceGrant{}, query.ReferenceGrantFromField, query.IndexerByObjType); err != nil {
+		errs = append(errs, err)
+	}
+
+	// Conditionally index for TCPRoute
+	if c.cfg.CRDs.Has(wellknown.TCPRouteCRD) {
+		if err := c.cfg.Mgr.GetFieldIndexer().IndexField(ctx, &apiv1a2.TCPRoute{}, query.TcpRouteTargetField, query.IndexerByObjType); err != nil {
+			errs = append(errs, err)
+		}
+	}
+
+	return errors.Join(errs...)
 }
 
 func (c *controllerBuilder) addGwParamsIndexes(ctx context.Context) error {
@@ -231,7 +251,7 @@ func (c *controllerBuilder) watchGw(ctx context.Context) error {
 			return fmt.Errorf("object %T is not a client.Object", obj)
 		}
 		log.Info("watching gvk as gateway child", "gvk", gvk)
-		// unless its a service, we don't care about the status
+		// unless it's a service, we don't care about the status
 		var opts []builder.OwnsOption
 		if shouldIgnoreStatusChild(gvk) {
 			opts = append(opts, builder.WithPredicates(predicate.GenerationChangedPredicate{}))
@@ -282,7 +302,7 @@ func (c *controllerBuilder) watchCustomResourceDefinitions(_ context.Context) er
 					return false
 				}
 				// Check if the CRD is one we care about
-				return wellknown.GatewayCRDs.Has(crd.Name)
+				return c.cfg.CRDs.Has(crd.Name)
 			}),
 		)).
 		For(&apiextensionsv1.CustomResourceDefinition{}).
@@ -296,7 +316,13 @@ func (c *controllerBuilder) watchHttpRoute(_ context.Context) error {
 		Complete(reconcile.Func(c.reconciler.ReconcileHttpRoutes))
 }
 
-func (c *controllerBuilder) watchTcpRoute(_ context.Context) error {
+func (c *controllerBuilder) watchTcpRoute(ctx context.Context) error {
+	if !c.cfg.CRDs.Has(wellknown.TCPRouteCRD) {
+		log.FromContext(ctx).Info("TCPRoute type not registered in scheme; skipping TCPRoute controller setup")
+		return nil
+	}
+
+	// Proceed to set up the controller for TCPRoute
 	return ctrl.NewControllerManagedBy(c.cfg.Mgr).
 		WithEventFilter(predicate.GenerationChangedPredicate{}).
 		For(&apiv1a2.TCPRoute{}).

projects/gateway2/controller/start.go

@@ -16,6 +16,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
+	gwv1a2 "sigs.k8s.io/gateway-api/apis/v1alpha2"
 
 	gatewaykubev1 "github.com/solo-io/gloo/projects/gateway/pkg/api/v1/kube/apis/gateway.solo.io/v1"
 	"github.com/solo-io/gloo/projects/gateway2/deployer"
@@ -98,9 +99,16 @@ func NewControllerBuilder(ctx context.Context, cfg StartConfig) (*ControllerBuil
 	}
 	ctrl.SetLogger(zap.New(opts...))
 
+	scheme := glooschemes.DefaultScheme()
+
+	// Extend the scheme if the TCPRoute CRD exists.
+	if err := glooschemes.AddGatewayV1A2Scheme(cfg.RestConfig, scheme); err != nil {
+		return nil, err
+	}
+
 	mgrOpts := ctrl.Options{
 		BaseContext:      func() context.Context { return ctx },
-		Scheme:           glooschemes.DefaultScheme(),
+		Scheme:           scheme,
 		PprofBindAddress: "127.0.0.1:9099",
 		// if you change the port here, also change the port "health" in the helmchart.
 		HealthProbeBindAddress: ":9093",
@@ -227,6 +235,12 @@ func (c *ControllerBuilder) Start(ctx context.Context) error {
 		}
 	}
 
+	// Initialize the set of Gateway API CRDs we care about
+	crds, err := getGatewayCRDs(c.cfg.RestConfig)
+	if err != nil {
+		return err
+	}
+
 	gwCfg := GatewayConfig{
 		Mgr:            c.mgr,
 		GWClasses:      sets.New(append(c.cfg.SetupOpts.ExtraGatewayClasses, wellknown.GatewayClassName)...),
@@ -241,6 +255,7 @@ func (c *ControllerBuilder) Start(ctx context.Context) error {
 		Aws:                     awsInfo,
 		Kick:                    c.inputChannels.Kick,
 		Extensions:              c.k8sGwExtensions,
+		CRDs:                    crds,
 	}
 	if err := NewBaseGatewayController(ctx, gwCfg); err != nil {
 		setupLog.Error(err, "unable to create controller")
@@ -249,3 +264,18 @@ func (c *ControllerBuilder) Start(ctx context.Context) error {
 
 	return c.mgr.Start(ctx)
 }
+
+func getGatewayCRDs(restConfig *rest.Config) (sets.Set[string], error) {
+	crds := wellknown.GatewayStandardCRDs
+
+	tcpRouteExists, err := glooschemes.CRDExists(restConfig, gwv1a2.GroupVersion.Group, gwv1a2.GroupVersion.Version, wellknown.TCPRouteKind)
+	if err != nil {
+		return nil, err
+	}
+
+	if tcpRouteExists {
+		crds.Insert(wellknown.TCPRouteCRD)
+	}
+
+	return crds, nil
+}