How to access an ASM ingress gateway via multiple CLBs - Alibaba Cloud Service Mesh

This topic describes how to bind an additional CLB instance to an ASM ingress gateway and use multiple CLBs to access it.

Prerequisites

The cluster is added to the ASM instance.
An ingress gateway is deployed. For more information, see Create an ingress gateway.

After the ingress gateway is deployed, a Service named istio-ingressgateway is automatically created in the ACK cluster.
The Bookinfo sample application and its Istio resources are deployed in the ASM instance. This allows you to access the application through the ingress gateway. For more information, see Deploy an application in an ACK cluster that is associated with an ASM instance and Use Istio resources for traffic routing.

Procedure

Create a new Service to provision an additional CLB instance for the ASM ingress gateway.

Note

Deleting the additional Service also deletes the corresponding CLB instance.

Log on to the ACK console. In the left navigation pane, click Clusters.
On the Cluster List page, click the name of the destination cluster or click Details in the Actions column.
In the left navigation pane of the cluster management page, choose Network > Services.
On the Services page, set the Namespace to istio-system, and then click Create Resources in YAML in the upper-right corner.

On the Create page, set Sample Template to Custom, copy the following content into the Template text box, and click Create.

Important

The nodePort value must not conflict with any existing ports in the cluster.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/alibaba-cloud-loadbalancer-spec: slb.s1.small
    service.beta.kubernetes.io/alicloud-loadbalancer-address-type: internet
  labels:
    app: istio-ingressgateway
    asm-system: 'true'
    istio: ingressgateway
  name: istio-ingressgateway-2
  namespace: istio-system
spec:
  externalTrafficPolicy: Cluster
  ports:
    - name: http-0
      nodePort: 30544
      port: 80
      protocol: TCP
      targetPort: 80
    - name: https-2
      nodePort: 30682
      port: 443
      protocol: TCP
      targetPort: 443
  selector:
    app: istio-ingressgateway
    asm-system: 'true'
    istio: ingressgateway
    provider: asm
  sessionAffinity: None
  type: LoadBalancer

name: The name of the service. In this topic, this parameter is set to istio-ingressgateway-2.
service.beta.kubernetes.io/alibaba-cloud-loadbalancer-spec: Sets the CLB instance specification. Valid values: slb.s1.small, slb.s2.small, slb.s2.medium, slb.s3.small, slb.s3.medium, and slb.s3.large.
service.beta.kubernetes.io/alicloud-loadbalancer-address-type: Specifies the network type of the CLB. Valid values:
- internet: Public network.
- intranet: private network.

After you create the Service, the system automatically provisions a new CLB instance.

Verify that the ASM ingress gateway is accessible through multiple CLB instances.
1. On the Services page, find the istio-ingressgateway and istio-ingressgateway-2 Services. For each Service, note its IP address for port 80 from the External IP column.
2. In your web browser, visit http://<External_IP_of_istio-ingressgateway>/productpage and http://<External_IP_of_istio-ingressgateway-2>/productpage separately.
  
  The product page for the Bookinfo Sample application is displayed, which includes a summary of the book The Comedy of Errors, a Book Details section (Type, Pages, Publisher, Language, ISBN, etc.), and a Book Reviews section (user ratings and reviews).
  
  The ASM ingress gateway is accessible through multiple CLB instances if the Bookinfo application page loads successfully from both addresses.