feat(translator): Set zone for endpoint and arrange endpoints by zone in EDS

internal/gatewayapi/route.go

@@ -1488,6 +1488,10 @@ func getIREndpointsFromEndpointSlice(endpointSlice *discoveryv1.EndpointSlice, p
 					ep := ir.NewDestEndpoint(
 						address,
 						uint32(*endpointPort.Port))
+
+					// EndpointSlice may set zone for individual endpoint, use it anyway.
+					ep.Zone = endpoint.Zone
+
 					endpoints = append(endpoints, ep)
 				}
 			}

internal/gatewayapi/testdata/httproute-attaching-to-listener-with-core-backendrefs-diff-zone.in.yaml

@@ -0,0 +1,201 @@
+gateways:
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: Gateway
+    metadata:
+      namespace: envoy-gateway
+      name: gateway-1
+    spec:
+      gatewayClassName: envoy-gateway-class
+      listeners:
+        - name: http
+          protocol: HTTP
+          port: 80
+          allowedRoutes:
+            namespaces:
+              from: All
+httpRoutes:
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      namespace: default
+      name: httproute-static
+    spec:
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-1
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/1"
+          backendRefs:
+            - name: service-ip
+              port: 8080
+            - name: service-import-ip
+              group: multicluster.x-k8s.io
+              kind: ServiceImport
+              port: 8081
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      namespace: default
+      name: httproute-fqdn
+    spec:
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-1
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/2"
+          backendRefs:
+            - name: service-fqdn
+              port: 8080
+            - name: service-import-fqdn
+              group: multicluster.x-k8s.io
+              kind: ServiceImport
+              port: 8081
+services:
+  - apiVersion: v1
+    kind: Service
+    metadata:
+      namespace: default
+      name: service-fqdn
+    spec:
+      clusterIP: 1.1.1.1
+      ports:
+        - name: http
+          port: 8080
+          protocol: TCP
+          targetPort: 8080
+  - apiVersion: v1
+    kind: Service
+    metadata:
+      namespace: default
+      name: service-ip
+    spec:
+      clusterIP: 2.2.2.2
+      ports:
+        - name: http
+          port: 8080
+          protocol: TCP
+          targetPort: 8080
+serviceImports:
+  - apiVersion: multicluster.x-k8s.io/v1alpha1
+    kind: ServiceImport
+    metadata:
+      namespace: default
+      name: service-import-fqdn
+    spec:
+      ips:
+        - 7.7.7.7
+      ports:
+        - port: 8081
+          name: http
+          protocol: TCP
+  - apiVersion: multicluster.x-k8s.io/v1alpha1
+    kind: ServiceImport
+    metadata:
+      namespace: default
+      name: service-import-ip
+    spec:
+      ips:
+        - 8.8.8.8
+      ports:
+        - port: 8081
+          name: http
+          protocol: TCP
+endpointSlices:
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: endpointslice-service-fqdn
+      namespace: default
+      labels:
+        kubernetes.io/service-name: service-fqdn
+    addressType: FQDN
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8080
+    endpoints:
+      - addresses:
+          - "bar.foo"
+        zone: "a"
+        conditions:
+          ready: true
+      - addresses:
+          - "abc.xyz"
+        zone: "b"
+        conditions:
+          ready: true
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: endpointslice-service-ip
+      namespace: default
+      labels:
+        kubernetes.io/service-name: service-ip
+    addressType: IP
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8080
+    endpoints:
+      - addresses:
+          - "4.3.2.1"
+        zone: "a"
+        conditions:
+          ready: true
+      - addresses:
+          - "8.7.6.5"
+        zone: "b"
+        conditions:
+          ready: true
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: service-import-fqdn
+      namespace: default
+      labels:
+        multicluster.kubernetes.io/service-name: service-import-fqdn
+    addressType: FQDN
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8081
+    endpoints:
+      - addresses:
+          - "foo.bar"
+        zone: "a"
+        conditions:
+          ready: true
+      - addresses:
+          - "xyz.abc"
+        zone: "b"
+        conditions:
+          ready: true
+  - apiVersion: discovery.k8s.io/v1
+    kind: EndpointSlice
+    metadata:
+      name: service-import-ip
+      namespace: default
+      labels:
+        multicluster.kubernetes.io/service-name: service-import-ip
+    addressType: IPv4
+    ports:
+      - name: http
+        protocol: TCP
+        port: 8081
+    endpoints:
+      - addresses:
+          - "1.2.3.4"
+        zone: "a"
+        conditions:
+          ready: true
+      - addresses:
+          - "5.6.7.8"
+        zone: "b"
+        conditions:
+          ready: true