Access an ingress gateway by using multiple CLB instances - Alibaba Cloud Service Mesh

You can associate multiple Classic Load Balancer (CLB) instances with a Service Mesh (ASM) ingress gateway so that multiple CLB instances can be used to access the ingress gateway. This topic describes how to access an ingress gateway by using multiple CLB instances that are associated with the ingress gateway.

Prerequisites

The cluster is added to the ASM instance. For more information, see Add a cluster to an ASM instance.
An ingress gateway is deployed in the Container Service for Kubernetes (ACK) cluster that is added to the ASM instance. 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 application and Istio resources are deployed in the ASM instance so that the Bookinfo application can be accessed by using the ingress gateway. For more information, see Deploy an application in an ASM instance and Use Istio resources to route traffic to different versions of a service.

Procedure

You need to create an additional CLB instance for the ingress gateway by creating a service with which the CLB instance is associated.

Note

If you delete the service associated with the CLB instance, the CLB instance is also deleted.

Log on to the ACK console.
In the left-side navigation pane of the ACK console, click Clusters.
On the Clusters page, find the cluster that you want to manage and click the name of the cluster or click Details in the Actions column. The details page of the cluster appears.
In the left-side navigation pane of the details page, choose Network > Services
In the upper part of the Services page, set the Namespace parameter to istio-system and click Create Resources in YAML in the upper-right corner.
On the Create page, select Custom from the Sample Template drop-down list, enter the following content in the Template field, and then click Create.
Important
The value of the nodePort parameter cannot be the same as an existing port number.
```
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 to be created. In this example, the value is set to istio-ingressgateway-2.
- service.beta.kubernetes.io/alibaba-cloud-loadbalancer-spec: the specifications of the CLB instance. 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: the network type of the CLB instance to be created. Valid values:
  - internet: an Internet-facing CLB instance
  - intranet: an internal-facing CLB instance
After the service is created, a CLB instance is automatically created.
Access the ingress gateway by using multiple CLB instances.
1. Obtain the IP addresses using port 80 of the istio-ingressgateway and istio-ingressgateway-2 services in the External IP column on the Services page.
2. Enter http://<IP address of the istio-ingressgateway service>/productpage and http://<IP address of the istio-ingressgateway-2 service}>/productpage in the address bar of the browser.
  If the page of the Bookinfo application appears after you enter each of the URLs, the preceding configurations take effect. In this case, you can access the ingress gateway by using multiple CLB instances.