change the default cluster naming

internal/gatewayapi/filters.go

@@ -1039,7 +1039,7 @@ func (t *Translator) processRequestMirrorFilter(
 			fmt.Errorf("failed to validate the RequestMirror filter: %w", err), err.Reason()).WithType(gwapiv1.RouteConditionResolvedRefs)
 	}
 
-	destName := fmt.Sprintf("%s-mirror-%d", irRouteDestinationName(filterContext.Route, filterContext.RuleIdx), filterIdx)
+	destName := fmt.Sprintf("%s-mirror-%d", irRouteDestinationName(t.XDSNameSchemeV2, filterContext.Route, filterContext.RuleIdx), filterIdx)
 	settingName := irDestinationSettingName(destName, -1 /*unused*/)
 	ds, _, err := t.processDestination(settingName, mirrorBackendRef, filterContext.ParentRef, filterContext.Route, resources)
 	if err != nil {

internal/gatewayapi/helpers.go

@@ -465,11 +465,21 @@ func irUDPRouteName(route RouteContext) string {
 	return irTCPRouteName(route)
 }
 
-func irRouteDestinationName(route RouteContext, ruleIdx int) string {
+// irRouteDestinationName returns the name for a route destination in the IR.
+// The format of the name depends on the xdsNameSchemeV2 flag:
+//   - If xdsNameSchemeV2 is true, the name will be "{routePrefix}rule/{ruleIdx}/backend/0"
+//     this will avoid naming changes for issue like https://github.com/envoyproxy/gateway/issues/6287.
+//   - If xdsNameSchemeV2 is false, the name will be "{routePrefix}rule/{ruleIdx}"
+func irRouteDestinationName(xdsNameSchemeV2 bool, route RouteContext, ruleIdx int) string {
+	if xdsNameSchemeV2 {
+		return fmt.Sprintf("%srule/%d/backend/0", irRoutePrefix(route), ruleIdx)
+	}
 	return fmt.Sprintf("%srule/%d", irRoutePrefix(route), ruleIdx)
 }
 
 func irDestinationSettingName(destName string, backendIdx int) string {
+	// Trim the "/backend/0" suffix if it exists to avoid duplication when appending the backend index
+	destName = strings.TrimSuffix(destName, "/backend/0")
 	return fmt.Sprintf("%s/backend/%d", destName, backendIdx)
 }
 

internal/gatewayapi/route.go

@@ -259,7 +259,7 @@ func (t *Translator) processHTTPRouteRules(httpRoute *HTTPRouteContext, parentRe
 		}
 
 		// process each backendRef, and calculate the destination settings for this rule
-		destName := irRouteDestinationName(httpRoute, ruleIdx)
+		destName := irRouteDestinationName(t.XDSNameSchemeV2, httpRoute, ruleIdx)
 		allDs := make([]*ir.DestinationSetting, 0, len(rule.BackendRefs))
 		var processDestinationError error
 		failedNoReadyEndpoints := false
@@ -586,7 +586,7 @@ func (t *Translator) processHTTPRouteRule(
 
 			// We generate a unique session name per route.
 			// `/` isn't allowed in the header key, so we just replace it with `-`.
-			sessionName = strings.ReplaceAll(irRouteDestinationName(httpRoute, ruleIdx), "/", "-")
+			sessionName = strings.ReplaceAll(irRouteDestinationName(t.XDSNameSchemeV2, httpRoute, ruleIdx), "/", "-")
 		} else {
 			sessionName = *rule.SessionPersistence.SessionName
 		}
@@ -980,7 +980,7 @@ func (t *Translator) processGRPCRouteRules(grpcRoute *GRPCRouteContext, parentRe
 		}
 
 		// process each backendRef, and calculate the destination settings for this rule
-		destName := irRouteDestinationName(grpcRoute, ruleIdx)
+		destName := irRouteDestinationName(t.XDSNameSchemeV2, grpcRoute, ruleIdx)
 		allDs := make([]*ir.DestinationSetting, 0, len(rule.BackendRefs))
 		var processDestinationError error
 		failedNoReadyEndpoints := false
@@ -1365,7 +1365,7 @@ func (t *Translator) processTLSRouteParentRefs(tlsRoute *TLSRouteContext, resour
 		var (
 			destSettings []*ir.DestinationSetting
 			resolveErrs  = &status.MultiStatusError{}
-			destName     = irRouteDestinationName(tlsRoute, -1 /*rule index*/)
+			destName     = irRouteDestinationName(t.XDSNameSchemeV2, tlsRoute, -1 /*rule index*/)
 		)
 
 		// compute backends
@@ -1544,7 +1544,7 @@ func (t *Translator) processUDPRouteParentRefs(udpRoute *UDPRouteContext, resour
 		var (
 			destSettings []*ir.DestinationSetting
 			resolveErrs  = &status.MultiStatusError{}
-			destName     = irRouteDestinationName(udpRoute, -1 /*rule index*/)
+			destName     = irRouteDestinationName(t.XDSNameSchemeV2, udpRoute, -1 /*rule index*/)
 		)
 
 		for i := range udpRoute.Spec.Rules[0].BackendRefs {
@@ -1695,7 +1695,7 @@ func (t *Translator) processTCPRouteParentRefs(tcpRoute *TCPRouteContext, resour
 		var (
 			destSettings []*ir.DestinationSetting
 			resolveErrs  = &status.MultiStatusError{}
-			destName     = irRouteDestinationName(tcpRoute, -1 /*rule index*/)
+			destName     = irRouteDestinationName(t.XDSNameSchemeV2, tcpRoute, -1 /*rule index*/)
 		)
 
 		for i := range tcpRoute.Spec.Rules[0].BackendRefs {

internal/gatewayapi/runner/runner.go

@@ -196,6 +196,7 @@ func (r *Runner) subscribeAndTranslate(sub <-chan watchable.Snapshot[string, *re
 					RunningOnHost:                   r.EnvoyGateway.Provider != nil && r.EnvoyGateway.Provider.IsRunningOnHost(),
 					Logger:                          traceLogger,
 					LuaEnvoyExtensionPolicyDisabled: r.EnvoyGateway.ExtensionAPIs != nil && r.EnvoyGateway.ExtensionAPIs.DisableLua,
+					XDSNameSchemeV2:                 r.EnvoyGateway.RuntimeFlags != nil && r.EnvoyGateway.RuntimeFlags.IsEnabled(egv1a1.XDSNameSchemeV2),
 				}
 
 				// If an extension is loaded, pass its supported groups/kinds to the translator

internal/gatewayapi/testdata/xds-name-scheme-v2.in.yaml

@@ -0,0 +1,76 @@
+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
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: Gateway
+    metadata:
+      namespace: envoy-gateway
+      name: gateway-2
+    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-1
+    spec:
+      hostnames:
+        - gateway.envoyproxy.io
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-1
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/"
+          backendRefs:
+            - name: service-1
+              port: 8080
+  - apiVersion: gateway.networking.k8s.io/v1
+    kind: HTTPRoute
+    metadata:
+      namespace: default
+      name: httproute-2
+    spec:
+      hostnames:
+        - gateway2.envoyproxy.io
+      parentRefs:
+        - namespace: envoy-gateway
+          name: gateway-2
+          sectionName: http
+      rules:
+        - matches:
+            - path:
+                value: "/"
+          backendRefs:
+            - name: service-1
+              port: 8080
+            - name: service-2
+              port: 8080
+              filters:
+                - type: ResponseHeaderModifier
+                  responseHeaderModifier:
+                    add:
+                      - name: backend
+                        value: service-2