feature: add ref grant

config/rbac/role.yaml

@@ -121,6 +121,18 @@ rules:
   - get
   - patch
   - update
+- apiGroups:
+  - gateway.networking.k8s.io
+  resources:
+  - referencegrants
+  verbs:
+  - create
+  - delete
+  - get
+  - list
+  - patch
+  - update
+  - watch
 - apiGroups:
   - gateway.networking.k8s.io
   resources:

config/samples/tcproute/gateway.yaml

@@ -3,13 +3,15 @@ kind: GatewayClass
 apiVersion: gateway.networking.k8s.io/v1beta1
 metadata:
   name: blixt-tcproute-sample
+  namespace: gwapi-ref-ns
 spec:
   controllerName: konghq.com/blixt
 ---
 kind: Gateway
 apiVersion: gateway.networking.k8s.io/v1beta1
 metadata:
   name: blixt-tcproute-sample
+  namespace: gwapi-ref-ns
 spec:
   gatewayClassName: blixt-tcproute-sample
   listeners:

config/samples/tcproute/server.yaml

@@ -40,3 +40,8 @@ spec:
   selector:
     app: blixt-tcproute-sample
   type: ClusterIP
+---
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: gwapi-ref-ns

config/samples/tcproute/tcproute.yaml

@@ -2,6 +2,7 @@ apiVersion: gateway.networking.k8s.io/v1alpha2
 kind: TCPRoute
 metadata:
   name: blixt-tcproute-sample
+  namespace: gwapi-ref-ns
 spec:
   parentRefs:
   - name: blixt-tcproute-sample
@@ -10,3 +11,18 @@ spec:
   - backendRefs:
     - name: blixt-tcproute-sample
       port: 8080
+      namespace: default
+---
+apiVersion: gateway.networking.k8s.io/v1beta1
+kind: ReferenceGrant
+metadata:
+  name: tcproute-sample-ref
+  namespace: default
+spec:
+  from:
+    - group: gateway.networking.k8s.io
+      kind: TCPRoute
+      namespace: gwapi-ref-ns
+  to:
+    - group: ""
+      kind: Service

controllers/gateway_controller.go

@@ -21,6 +21,7 @@ import (
 )
 
 //+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=gateways,verbs=get;list;watch;create;update;patch;delete
+//+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=referencegrants,verbs=get;list;watch;create;update;patch;delete
 //+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=gateways/status,verbs=get;update;patch
 //+kubebuilder:rbac:groups=gateway.networking.k8s.io,resources=gateways/finalizers,verbs=update
 

internal/dataplane/client/utils.go

@@ -3,6 +3,7 @@ package client
 import (
 	context "context"
 	"encoding/binary"
+	"errors"
 	"fmt"
 	"net"
 
@@ -40,7 +41,12 @@ func CompileUDPRouteToDataPlaneBackend(ctx context.Context, c client.Client, udp
 	// TODO only using one endpoint for now until https://github.com/Kong/blixt/issues/10
 	var target *Target
 	if udproute.DeletionTimestamp == nil {
-		endpoints, err := endpointsFromBackendRef(ctx, c, udproute.Namespace, backendRef)
+		from := objectKindNamespacedName{
+			kind:      udproute.Kind,
+			namespace: udproute.Namespace,
+			name:      udproute.Name,
+		}
+		endpoints, err := endpointsFromBackendRef(ctx, from, c, udproute.Namespace, backendRef)
 		if err != nil {
 			return nil, err
 		}
@@ -112,7 +118,12 @@ func CompileTCPRouteToDataPlaneBackend(ctx context.Context, c client.Client, tcp
 	// TODO only using one endpoint for now until https://github.com/Kong/blixt/issues/10
 	var target *Target
 	if tcproute.DeletionTimestamp == nil {
-		endpoints, err := endpointsFromBackendRef(ctx, c, tcproute.Namespace, backendRef)
+		from := objectKindNamespacedName{
+			kind:      tcproute.Kind,
+			namespace: tcproute.Namespace,
+			name:      tcproute.Name,
+		}
+		endpoints, err := endpointsFromBackendRef(ctx, from, c, tcproute.Namespace, backendRef)
 		if err != nil {
 			return nil, err
 		}
@@ -156,9 +167,46 @@ func CompileTCPRouteToDataPlaneBackend(ctx context.Context, c client.Client, tcp
 	return targets, nil
 }
 
-func endpointsFromBackendRef(ctx context.Context, c client.Client, namespace string, backendRef gatewayv1alpha2.BackendRef) (*corev1.Endpoints, error) {
-	if backendRef.Namespace != nil {
-		namespace = string(*backendRef.Namespace)
+type objectKindNamespacedName struct {
+	kind      string
+	namespace string
+	name      string
+}
+
+func endpointsFromBackendRef(ctx context.Context, from objectKindNamespacedName, c client.Client, namespace string, backendRef gatewayv1alpha2.BackendRef) (*corev1.Endpoints, error) {
+	refGrantFoundOrNotNeeded := false
+	if backendRef.Namespace != nil && from.namespace != string(*backendRef.Namespace) {
+		refGrantList := &gatewayv1beta1.ReferenceGrantList{}
+		err := c.List(ctx, refGrantList, &client.ListOptions{Namespace: string(*backendRef.Namespace)})
+		for _, refGrant := range refGrantList.Items {
+			useRefGrant := false
+			for _, dest := range refGrant.Spec.To {
+				if dest.Group == "" && dest.Kind == "Service" {
+					useRefGrant = true
+					break
+				}
+			}
+			if !useRefGrant {
+				continue
+			}
+			for _, src := range refGrant.Spec.From {
+				if src.Kind == gatewayv1alpha2.Kind(from.kind) && string(src.Namespace) == from.namespace {
+					refGrantFoundOrNotNeeded = true
+					namespace = string(*backendRef.Namespace)
+					break
+				}
+			}
+		}
+		if err != nil {
+			return nil, errors.New("not able to list reference grant")
+		}
+
+	} else if backendRef.Namespace == nil {
+		refGrantFoundOrNotNeeded = true
+	}
+
+	if !refGrantFoundOrNotNeeded {
+		return nil, errors.New("route does not have reference grant for endpoints")
 	}
 
 	endpoints := new(corev1.Endpoints)