Alibaba Cloud Service Mesh:VirtualService delegation in ASM

Notes

• ASM does not support nested Delegates. The Delegate parameter can be set only in a primary VirtualService. For example, if the Delegate parameter is set in both a primary VirtualService and a secondary VirtualService, neither the primary VirtualService nor the secondary VirtualService will take effect.

• The HTTPMatchRequest in a secondary VirtualService must be a subset of the corresponding match condition in the primary VirtualService. Otherwise, a conflict occurs and the HTTPRoute will not take effect.

• You can specify the delegate field only when the route and redirect fields in the primary VirtualService's HTTP route are empty. The hosts field of a secondary VirtualService must be empty. The routing rules from the secondary VirtualService are merged with those from the primary VirtualService.

Step 1: Configure Gateway

1. Log on to the ASM console.

2. In the left-side navigation pane, choose Service Mesh > Mesh Management.

3. On the Mesh Management page, find the ASM instance that you want to configure. Click the name of the ASM instance or click Manage in the Actions column.

4. On the details page of the ASM instance, choose ASM Gateways > Gateway in the left-side navigation pane. On the page that appears, click Create from YAML.

5. Select a Namespaces, paste the following YAML content into the editor, and click Create. This topic uses the default namespace as an example.

   apiVersion: networking.istio.io/v1alpha3
   kind: Gateway
   metadata:
     name: bookinfo-gateway
   spec:
     selector:
       istio: ingressgateway # use istio default controller
     servers:
     - port:
         number: 80
         name: http
         protocol: HTTP
       hosts:
       - "*"

   Set number to 80 so that the Bookinfo service can receive incoming or outgoing HTTP connections on port 80.

Step 2: Configure the primary VirtualService

1. Log on to the ASM console.

2. In the left-side navigation pane, choose Service Mesh > Mesh Management.

3. On the Mesh Management page, find the ASM instance that you want to configure. Click the name of the ASM instance or click Manage in the Actions column.

4. On the details page of the ASM instance, choose Traffic Management Center > VirtualService in the left-side navigation pane. On the page that appears, click Create from YAML.

5. Select a Namespaces, paste the following YAML content into the editor, and click Create. This topic uses the default namespace as an example.

   The following creates delegates for vs-1 and vs-2, where vs-1 requires requests to contain /log to access the Bookinfo service, and vs-2 requires requests to contain / to access the Bookinfo service.

   apiVersion: networking.istio.io/v1beta1
   kind: VirtualService
   metadata:
     name: bookinfo
     namespace: default
   spec:
     gateways:
       - bookinfo-gateway
     hosts:
       - '*'
     http:
       - delegate:
           name: vs-1
           namespace: ns1
         match:
           - uri:
               prefix: /log
       - delegate:
           name: vs-2
           namespace: ns1
         match:
           - uri:
               prefix: /

   Parameters in the delegate field:

   • name: The name of the delegate.

   • namespace: The namespace of the delegate.

Step 3: Configure the child VirtualService

1. Log on to the ASM console.

2. In the left-side navigation pane, choose Service Mesh > Mesh Management.

3. On the Mesh Management page, find the ASM instance that you want to configure. Click the name of the ASM instance or click Manage in the Actions column.

4. On the details page of the ASM instance, choose Traffic Management Center > VirtualService in the left-side navigation pane. On the page that appears, click Create from YAML.

5. Select a Namespaces, paste the following content into the editor, and click Create.

   This topic uses the ns1 namespace as an example. For more information about how to create a namespace, see Manage global namespaces.

   apiVersion: networking.istio.io/v1beta1
   kind: VirtualService
   metadata:
     name: vs-1
     namespace: ns1
   spec:
     http:
       - match:
           - uri:
               exact: /login
           - uri:
               exact: /logout
         route:
           - destination:
               host: productpage.default.svc.cluster.local
               port:
                 number: 9080

   • metadata: Must be consistent with the delegate parameter of the primary VirtualService to bind the delegate parameter. In this example, the metadata is consistent with the delegate parameter of vs-1, which binds the delegate parameter of vs-1.

   • match: Specifies the filter conditions for requests. In this example, uri is set to exact: /login and exact: /logout. This allows you to log in to and log out of the Bookinfo service.

6. Again, select the ns1 Namespaces, paste the following YAML content into the editor, and click Create.

   apiVersion: networking.istio.io/v1beta1
   kind: VirtualService
   metadata:
     name: vs-2
     namespace: ns1
   spec:
     http:
       - match:
           - uri:
               exact: /productpage
           - uri:
               prefix: /static
           - uri:
               prefix: /api/v1/products
         route:
           - destination:
               host: productpage.default.svc.cluster.local
               port:
                 number: 9080

   • metadata: The value must be consistent with the delegate parameter of the primary VirtualService. This is used to bind to the delegate parameter. In this example, the value is consistent with the delegate parameter of vs-2, which means it is bound to the delegate of vs-2.

   • match: Specifies the filter conditions for a request. In this example, the request must contain /productpage, /static, or /api/v1/products.

Verify the results

1. In your web browser, navigate to http://<ingress gateway IP address>/productpage.

   The following page is displayed. This indicates that the request to the Bookinfo service that contains the /productpage parameter was successful, and that the VirtualService for vs-2 is configured successfully. For information about how to obtain the ASM gateway address, see Obtain the ingress gateway IP address. The page successfully loads the BookInfo Sample application and displays the product page for the book The Comedy of Errors. The Book Details section on the left lists fields such as Type, Pages, Publisher, Language, and ISBN. The Book Reviews section on the right displays multiple user reviews and star ratings. This confirms that the service mesh application is accessible through the ASM gateway.

2. Click Sign in in the upper-right corner of the page. In the dialog box that appears, enter a username and password to sign in to the Bookinfo service.

   The page updates to a logged-in state. This confirms that the vs-1 VirtualService is configured correctly. After you sign in, your username (for example, jason) and a sign out link appear in the upper-right corner, confirming a successful sign-in.