Endpoint Slice support for ServiceImport

internal/gatewayapi/resource.go

@@ -106,11 +106,18 @@ func (r *Resources) GetSecret(namespace, name string) *v1.Secret {
 	return nil
 }
 
-func (r *Resources) GetEndpointSlicesForService(svcNamespace, svcName string) []*discoveryv1.EndpointSlice {
+func (r *Resources) GetEndpointSlicesForBackend(svcNamespace, svcName string, backendKind string) []*discoveryv1.EndpointSlice {
 	endpointSlices := []*discoveryv1.EndpointSlice{}
 	for _, endpointSlice := range r.EndpointSlices {
+		var backendSelectorLabel string
+		switch backendKind {
+		case KindService:
+			backendSelectorLabel = discoveryv1.LabelServiceName
+		case KindServiceImport:
+			backendSelectorLabel = mcsapi.LabelServiceName
+		}
 		if svcNamespace == endpointSlice.Namespace &&
-			endpointSlice.GetLabels()[discoveryv1.LabelServiceName] == svcName {
+			endpointSlice.GetLabels()[backendSelectorLabel] == svcName {
 			endpointSlices = append(endpointSlices, endpointSlice)
 		}
 	}

internal/gatewayapi/route.go

@@ -11,9 +11,11 @@
 	"time"
 
 	corev1 "k8s.io/api/core/v1"
+	v1 "k8s.io/api/discovery/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"sigs.k8s.io/gateway-api/apis/v1alpha2"
 	"sigs.k8s.io/gateway-api/apis/v1beta1"
+	mcsapi "sigs.k8s.io/mcs-api/pkg/apis/v1alpha1"
 
 	"github.com/envoyproxy/gateway/internal/ir"
 	"github.com/envoyproxy/gateway/internal/utils/ptr"
@@ -1009,14 +1011,26 @@
 
 	var endpoints []*ir.DestinationEndpoint
 	switch KindDerefOr(backendRef.Kind, KindService) {
-	// TODO: Use EndpointSlice for ServiceImport
 	case KindServiceImport:
-		backendIps := resources.GetServiceImport(backendNamespace, string(backendRef.Name)).Spec.IPs
-		for _, ip := range backendIps {
-			ep := ir.NewDestEndpoint(
-				ip,
-				uint32(*backendRef.Port))
-			endpoints = append(endpoints, ep)
+		serviceImport := resources.GetServiceImport(backendNamespace, string(backendRef.Name))
+		var servicePort mcsapi.ServicePort
+		for _, port := range serviceImport.Spec.Ports {
+			if port.Port == int32(*backendRef.Port) {
+				servicePort = port
+				break
+			}
+		}
+		if !t.EndpointRoutingDisabled {
+			endpointSlices := resources.GetEndpointSlicesForBackend(backendNamespace, string(backendRef.Name), KindDerefOr(backendRef.Kind, KindService))
+			endpoints = getIREndpointsFromEndpointSlice(endpointSlices, servicePort.Name, servicePort.Protocol)
+		} else {
+			backendIps := resources.GetServiceImport(backendNamespace, string(backendRef.Name)).Spec.IPs
+			for _, ip := range backendIps {
+				ep := ir.NewDestEndpoint(
+					ip,
+					uint32(*backendRef.Port))
+				endpoints = append(endpoints, ep)
+			}
 		}
 	case KindService:
 		service := resources.GetService(backendNamespace, string(backendRef.Name))
@@ -1030,26 +1044,8 @@
 
 		// Route to endpoints by default
 		if !t.EndpointRoutingDisabled {
-			endpointSlices := resources.GetEndpointSlicesForService(backendNamespace, string(backendRef.Name))
-
-			for _, endpointSlice := range endpointSlices {
-				for _, endpoint := range endpointSlice.Endpoints {
-					for _, endpointPort := range endpointSlice.Ports {
-						// Check if the endpoint port matches the service port
-						// and if endpoint is Ready
-						if *endpointPort.Name == servicePort.Name &&
-							*endpointPort.Protocol == servicePort.Protocol &&
-							*endpoint.Conditions.Ready {
-							for _, address := range endpoint.Addresses {
-								ep := ir.NewDestEndpoint(
-									address,
-									uint32(servicePort.TargetPort.IntVal))
-								endpoints = append(endpoints, ep)
-							}
-						}
-					}
-				}
-			}
+			endpointSlices := resources.GetEndpointSlicesForBackend(backendNamespace, string(backendRef.Name), KindDerefOr(backendRef.Kind, KindService))
+			endpoints = getIREndpointsFromEndpointSlice(endpointSlices, servicePort.Name, servicePort.Protocol)
 		} else {
 			// Fall back to Service CluserIP routing
 			ep := ir.NewDestEndpoint(
@@ -1135,3 +1131,27 @@
 	}
 	return relevantRoute
 }
+
+func getIREndpointsFromEndpointSlice(endpointSlices []*v1.EndpointSlice, portName string, portProtocol corev1.Protocol) []*ir.DestinationEndpoint {
+	endpoints := []*ir.DestinationEndpoint{}
+	for _, endpointSlice := range endpointSlices {
+		for _, endpoint := range endpointSlice.Endpoints {
+			for _, endpointPort := range endpointSlice.Ports {
+				// Check if the endpoint port matches the service port
+				// and if endpoint is Ready
+				if *endpointPort.Name == portName &&
+					*endpointPort.Protocol == portProtocol &&
+					*endpoint.Conditions.Ready {
+					for _, address := range endpoint.Addresses {
+						ep := ir.NewDestEndpoint(
+							address,
+							uint32(*endpointPort.Port))
+						endpoints = append(endpoints, ep)
+					}
+				}
+			}
+		}
+	}
+
+	return endpoints
+}

internal/gatewayapi/testdata/httproute-attaching-to-listener-with-serviceimport-backendref.in.yaml

@@ -44,3 +44,23 @@ serviceImports:
         - 7.7.7.7
       ports:
         - port: 8080
+          name: http
+          protocol: TCP
+endpointSlices:
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: service-import-1
+      namespace: default
+      labels:
+        multicluster.kubernetes.io/service-name: service-import-1
+    addressType: IPv4
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8080
+    endpoints:
+      - addresses:
+          - "8.8.8.8"
+        conditions:
+          ready: true

internal/gatewayapi/testdata/httproute-attaching-to-listener-with-serviceimport-backendref.out.yaml

@@ -108,7 +108,7 @@ xdsIR:
           name: httproute/default/httproute-1/rule/0
           settings:
           - endpoints:
-            - host: 7.7.7.7
+            - host: 8.8.8.8
               port: 8080
             weight: 1
         hostname: '*'

internal/gatewayapi/testdata/httproute-with-backendref-serviceimport-in-other-namespace-allowed-by-refgrant.in.yaml

@@ -45,6 +45,26 @@ serviceImports:
         - 7.7.7.7
       ports:
         - port: 8080
+          name: http
+          protocol: TCP
+endpointSlices:
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: service-import-1
+      namespace: backends
+      labels:
+        multicluster.kubernetes.io/service-name: service-import-1
+    addressType: IPv4
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8080
+    endpoints:
+      - addresses:
+          - "8.8.8.8"
+        conditions:
+          ready: true
 referenceGrants:
   - apiVersion: gateway.networking.k8s.io/v1alpha2
     kind: ReferenceGrant

internal/gatewayapi/testdata/httproute-with-backendref-serviceimport-in-other-namespace-allowed-by-refgrant.out.yaml

@@ -108,7 +108,7 @@ xdsIR:
           name: httproute/default/httproute-1/rule/0
           settings:
           - endpoints:
-            - host: 7.7.7.7
+            - host: 8.8.8.8
               port: 8080
             weight: 1
         hostname: '*'