fix(appmesh): Move Client Policy from Virtual Service to backend structure

packages/@aws-cdk-containers/ecs-service-extensions/lib/extensions/appmesh.ts

@@ -347,7 +347,7 @@ export class AppMeshExtension extends ServiceExtension {
     // Next update the app mesh config so that the local Envoy
     // proxy on this service knows how to route traffic to
     // nodes from the other service.
-    this.virtualNode.addBackend(otherAppMesh.virtualService);
+    this.virtualNode.addBackend(appmesh.Backend.virtualService({ virtualService: otherAppMesh.virtualService }));
   }
 
   private routeSpec(weightedTargets: appmesh.WeightedTarget[], serviceName: string): appmesh.RouteSpec {

packages/@aws-cdk/aws-appmesh/README.md

@@ -186,9 +186,11 @@ const node = new VirtualNode(this, 'node', {
       idle: cdk.Duration.seconds(5),
     },
   })],
-  backendsDefaultClientPolicy: appmesh.ClientPolicy.fileTrust({
-    certificateChain: '/keys/local_cert_chain.pem',
-  }),
+  backendDefaults: {
+    clientPolicy: appmesh.ClientPolicy.fileTrust({
+      certificateChain: '/keys/local_cert_chain.pem',
+    }),
+  },
   accessLog: appmesh.AccessLog.fromFilePath('/dev/stdout'),
 });
 
@@ -230,14 +232,16 @@ const virtualService = new appmesh.VirtualService(stack, 'service-1', {
   }),
 });
 
-node.addBackend(virtualService);
+node.addBackend(appmesh.Backend.virtualService({
+  virtualService: virtualService,
+}));
 ```
 
 The `listeners` property can be left blank and added later with the `node.addListener()` method. The `healthcheck` and `timeout` properties are optional but if specifying a listener, the `port` must be added.
 
 The `backends` property can be added with `node.addBackend()`. We define a virtual service and add it to the virtual node to allow egress traffic to other node.
 
-The `backendsDefaultClientPolicy` property are added to the node while creating the virtual node. These are virtual node's service backends client policy defaults.
+The `backendDefaults` property are added to the node while creating the virtual node. These are virtual node's default settings for all backends.
 
 ## Adding TLS to a listener
 
@@ -369,10 +373,12 @@ const gateway = new appmesh.VirtualGateway(stack, 'gateway', {
       interval: cdk.Duration.seconds(10),
     },
   })],
-  backendsDefaultClientPolicy: appmesh.ClientPolicy.acmTrust({
-    certificateAuthorities: [acmpca.CertificateAuthority.fromCertificateAuthorityArn(stack, 'certificate', certificateAuthorityArn)],
-    ports: [8080, 8081],
-  }),
+  backendDefaults: {
+    clientPolicy: appmesh.ClientPolicy.acmTrust({
+      certificateAuthorities: [acmpca.CertificateAuthority.fromCertificateAuthorityArn(stack, 'certificate', certificateAuthorityArn)],
+      ports: [8080, 8081],
+    }),
+  },
   accessLog: appmesh.AccessLog.fromFilePath('/dev/stdout'),
   virtualGatewayName: 'virtualGateway',
 });
@@ -396,7 +402,7 @@ const gateway = mesh.addVirtualGateway('gateway', {
 The listeners field can be omitted which will default to an HTTP Listener on port 8080.
 A gateway route can be added using the `gateway.addGatewayRoute()` method.
 
-The `backendsDefaultClientPolicy` property are added to the node while creating the virtual gateway. These are virtual gateway's service backends client policy defaults.
+The `backendDefaults` property is added to the node while creating the virtual gateway. These are virtual gateway's default settings for all backends.
 
 ## Adding a Gateway Route
 

packages/@aws-cdk/aws-appmesh/lib/shared-interfaces.ts

@@ -1,5 +1,7 @@
 import * as cdk from '@aws-cdk/core';
 import { CfnVirtualGateway, CfnVirtualNode } from './appmesh.generated';
+import { ClientPolicy } from './client-policy';
+import { IVirtualService } from './virtual-service';
 
 // keep this import separate from other imports to reduce chance for merge conflicts with v2-main
 // eslint-disable-next-line no-duplicate-imports, import/order
@@ -194,3 +196,84 @@ class FileAccessLog extends AccessLog {
   }
 }
 
+/**
+ * Represents the properties needed to define backend defaults
+ */
+export interface BackendDefaults {
+  /**
+   * Client policy for backend defaults
+   *
+   * @default none
+   */
+  readonly clientPolicy?: ClientPolicy;
+}
+
+/**
+ * Represents the properties needed to define a Virtual Service backend
+ */
+export interface VirtualServiceBackendOptions {
+  /**
+   * The Virtual Service this backend points to
+   */
+  readonly virtualService: IVirtualService;
+
+  /**
+   * Client policy for the backend
+   *
+   * @default none
+   */
+  readonly clientPolicy?: ClientPolicy;
+}
+
+/**
+ * Properties for a backend
+ */
+export interface BackendConfig {
+  /**
+   * Config for a Virtual Service backend
+   */
+  readonly virtualServiceBackend: CfnVirtualNode.BackendProperty;
+}
+
+
+/**
+ * Contains static factory methods to create backends
+ */
+export abstract class Backend {
+  /**
+   * Construct a Virtual Service backend
+   */
+  public static virtualService(props: VirtualServiceBackendOptions): Backend {
+    return new VirtualServiceBackend(props.virtualService, props.clientPolicy);
+  }
+
+  /**
+   * Return backend config
+   */
+  public abstract bind(_scope: Construct): BackendConfig;
+}
+
+/**
+ * Represents the properties needed to define a Virtual Service backend
+ */
+class VirtualServiceBackend extends Backend {
+
+  constructor (private readonly virtualService: IVirtualService,
+    private readonly clientPolicy: ClientPolicy | undefined) {
+    super();
+  }
+
+  /**
+   * Return config for a Virtual Service backend
+   */
+  public bind(_scope: Construct): BackendConfig {
+    return {
+      virtualServiceBackend: {
+        virtualService: {
+          virtualServiceName: this.virtualService.virtualServiceName,
+          clientPolicy: this.clientPolicy?.bind(_scope).clientPolicy,
+        },
+      },
+    };
+  }
+}

packages/@aws-cdk/aws-appmesh/lib/virtual-gateway.ts

@@ -1,10 +1,9 @@
 import * as cdk from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { CfnVirtualGateway } from './appmesh.generated';
-import { ClientPolicy } from './client-policy';
 import { GatewayRoute, GatewayRouteBaseProps } from './gateway-route';
 import { IMesh, Mesh } from './mesh';
-import { AccessLog } from './shared-interfaces';
+import { AccessLog, BackendDefaults } from './shared-interfaces';
 import { VirtualGatewayListener, VirtualGatewayListenerConfig } from './virtual-gateway-listener';
 
 /**
@@ -66,7 +65,7 @@ export interface VirtualGatewayBaseProps {
    *
    * @default - No Config
    */
-  readonly backendsDefaultClientPolicy?: ClientPolicy;
+  readonly backendDefaults?: BackendDefaults;
 }
 
 /**
@@ -180,7 +179,11 @@ export class VirtualGateway extends VirtualGatewayBase {
       meshName: this.mesh.meshName,
       spec: {
         listeners: this.listeners.map(listener => listener.listener),
-        backendDefaults: props.backendsDefaultClientPolicy?.bind(this),
+        backendDefaults: props.backendDefaults !== undefined
+          ? {
+            clientPolicy: props.backendDefaults?.clientPolicy?.bind(this).clientPolicy,
+          }
+          : undefined,
         logging: accessLogging !== undefined ? {
           accessLog: accessLogging.virtualGatewayAccessLog,
         } : undefined,

packages/@aws-cdk/aws-appmesh/lib/virtual-node.ts

@@ -1,12 +1,10 @@
 import * as cdk from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { CfnVirtualNode } from './appmesh.generated';
-import { ClientPolicy } from './client-policy';
 import { IMesh, Mesh } from './mesh';
 import { ServiceDiscovery } from './service-discovery';
-import { AccessLog } from './shared-interfaces';
+import { AccessLog, BackendDefaults, Backend } from './shared-interfaces';
 import { VirtualNodeListener, VirtualNodeListenerConfig } from './virtual-node-listener';
-import { IVirtualService } from './virtual-service';
 
 /**
  * Interface which all VirtualNode based classes must implement
@@ -61,7 +59,7 @@ export interface VirtualNodeBaseProps {
    *
    * @default - No backends
    */
-  readonly backends?: IVirtualService[];
+  readonly backends?: Backend[];
 
   /**
    * Initial listener for the virtual node
@@ -82,7 +80,7 @@ export interface VirtualNodeBaseProps {
    *
    * @default - No Config
    */
-  readonly backendsDefaultClientPolicy?: ClientPolicy;
+  readonly backendDefaults?: BackendDefaults;
 }
 
 /**
@@ -185,7 +183,11 @@ export class VirtualNode extends VirtualNodeBase {
       spec: {
         backends: cdk.Lazy.anyValue({ produce: () => this.backends }, { omitEmptyArray: true }),
         listeners: cdk.Lazy.anyValue({ produce: () => this.listeners.map(listener => listener.listener) }, { omitEmptyArray: true }),
-        backendDefaults: props.backendsDefaultClientPolicy?.bind(this),
+        backendDefaults: props.backendDefaults !== undefined
+          ? {
+            clientPolicy: props.backendDefaults?.clientPolicy?.bind(this).clientPolicy,
+          }
+          : undefined,
         serviceDiscovery: {
           dns: serviceDiscovery?.dns,
           awsCloudMap: serviceDiscovery?.cloudmap,
@@ -214,13 +216,8 @@ export class VirtualNode extends VirtualNodeBase {
   /**
    * Add a Virtual Services that this node is expected to send outbound traffic to
    */
-  public addBackend(virtualService: IVirtualService) {
-    this.backends.push({
-      virtualService: {
-        virtualServiceName: virtualService.virtualServiceName,
-        clientPolicy: virtualService.clientPolicy?.bind(this).clientPolicy,
-      },
-    });
+  public addBackend(backend: Backend) {
+    this.backends.push(backend.bind(this).virtualServiceBackend);
   }
 }
 

packages/@aws-cdk/aws-appmesh/lib/virtual-service.ts

@@ -1,7 +1,6 @@
 import * as cdk from '@aws-cdk/core';
 import { Construct } from 'constructs';
 import { CfnVirtualService } from './appmesh.generated';
-import { ClientPolicy } from './client-policy';
 import { IMesh, Mesh } from './mesh';
 import { IVirtualNode } from './virtual-node';
 import { IVirtualRouter } from './virtual-router';
@@ -28,11 +27,6 @@ export interface IVirtualService extends cdk.IResource {
    * The Mesh which the VirtualService belongs to
    */
   readonly mesh: IMesh;
-
-  /**
-   * Client policy for this Virtual Service
-   */
-  readonly clientPolicy?: ClientPolicy;
 }
 
 /**
@@ -50,13 +44,6 @@ export interface VirtualServiceProps {
    */
   readonly virtualServiceName?: string;
 
-  /**
-   * Client policy for this Virtual Service
-   *
-   * @default - none
-   */
-  readonly clientPolicy?: ClientPolicy;
-
   /**
    * The VirtualNode or VirtualRouter which the VirtualService uses as its provider
    */
@@ -90,7 +77,6 @@ export class VirtualService extends cdk.Resource implements IVirtualService {
     return new class extends cdk.Resource implements IVirtualService {
       readonly virtualServiceName = attrs.virtualServiceName;
       readonly mesh = attrs.mesh;
-      readonly clientPolicy = attrs.clientPolicy;
       readonly virtualServiceArn = cdk.Stack.of(this).formatArn({
         service: 'appmesh',
         resource: `mesh/${attrs.mesh.meshName}/virtualService`,
@@ -114,14 +100,11 @@ export class VirtualService extends cdk.Resource implements IVirtualService {
    */
   public readonly mesh: IMesh;
 
-  public readonly clientPolicy?: ClientPolicy;
-
   constructor(scope: Construct, id: string, props: VirtualServiceProps) {
     super(scope, id, {
       physicalName: props.virtualServiceName || cdk.Lazy.string({ produce: () => cdk.Names.uniqueId(this) }),
     });
 
-    this.clientPolicy = props.clientPolicy;
     const providerConfig = props.virtualServiceProvider.bind(this);
     this.mesh = providerConfig.mesh;
 
@@ -160,13 +143,6 @@ export interface VirtualServiceAttributes {
    * The Mesh which the VirtualService belongs to
    */
   readonly mesh: IMesh;
-
-  /**
-   * Client policy for this Virtual Service
-   *
-   * @default - none
-   */
-  readonly clientPolicy?: ClientPolicy;
 }
 
 /**

packages/@aws-cdk/aws-appmesh/test/integ.mesh.ts

@@ -36,16 +36,17 @@ const node = mesh.addVirtualNode('node', {
       path: '/check-path',
     },
   })],
-  backends: [
-    virtualService,
-  ],
+  backends: [appmesh.Backend.virtualService({
+    virtualService: virtualService,
+  })],
 });
 
-node.addBackend(new appmesh.VirtualService(stack, 'service-2', {
-  virtualServiceName: 'service2.domain.local',
-  virtualServiceProvider: appmesh.VirtualServiceProvider.none(mesh),
-}),
-);
+node.addBackend(appmesh.Backend.virtualService({
+  virtualService: new appmesh.VirtualService(stack, 'service-2', {
+    virtualServiceName: 'service2.domain.local',
+    virtualServiceProvider: appmesh.VirtualServiceProvider.none(mesh),
+  }),
+}));
 
 router.addRoute('route-1', {
   routeSpec: appmesh.RouteSpec.http({
@@ -78,15 +79,17 @@ const node2 = mesh.addVirtualNode('node2', {
       unhealthyThreshold: 2,
     },
   })],
-  backendsDefaultClientPolicy: appmesh.ClientPolicy.fileTrust({
-    certificateChain: 'path/to/cert',
-  }),
-  backends: [
-    new appmesh.VirtualService(stack, 'service-3', {
+  backendDefaults: {
+    clientPolicy: appmesh.ClientPolicy.fileTrust({
+      certificateChain: 'path/to/cert',
+    }),
+  },
+  backends: [appmesh.Backend.virtualService({
+    virtualService: new appmesh.VirtualService(stack, 'service-3', {
       virtualServiceName: 'service3.domain.local',
       virtualServiceProvider: appmesh.VirtualServiceProvider.none(mesh),
     }),
-  ],
+  })],
 });
 
 const node3 = mesh.addVirtualNode('node3', {
@@ -102,9 +105,11 @@ const node3 = mesh.addVirtualNode('node3', {
       unhealthyThreshold: 2,
     },
   })],
-  backendsDefaultClientPolicy: appmesh.ClientPolicy.fileTrust({
-    certificateChain: 'path-to-certificate',
-  }),
+  backendDefaults: {
+    clientPolicy: appmesh.ClientPolicy.fileTrust({
+      certificateChain: 'path-to-certificate',
+    }),
+  },
   accessLog: appmesh.AccessLog.fromFilePath('/dev/stdout'),
 });