Use ASM to deploy an application in multiple clusters in the same VPC - Alibaba Cloud Service Mesh

Service Mesh (ASM) allows you to deploy the microservices of an application in multiple clusters in the same Virtual Private Cloud (VPC). This topic uses the Bookinfo application as an example to describe how to deploy an application in two clusters that share the same VPC and are added to the same ASM instance.

Prerequisites

Two Container Service for Kubernetes (ACK) clusters are created in the same VPC. For more information, see Create an ACK dedicated cluster. In this topic, the two clusters are m1c1 and m1c2.
An ASM instance is created. For more information, see Create an ASM instance. In this topic, the ASM instance is mesh1.

Step 1: Change the security group names for the two clusters

Change the security group names for the two clusters. Make sure that users can deduce the corresponding clusters from the new security group names. In this example, change the security group names to m1c1-sg and m1c2-sg.

Log on to the ECS console.
In the left-side navigation pane, choose Network & Security > Security Groups.
In the top navigation bar, select a region.
On the Security Groups page, find the security group that you want to modify and click Modify in the Actions column.
In the Modify Security Group dialog box, modify Security Group Name and Description.
Click OK.

The following figure shows the new security group names.

Step 2: Set security group rules to allow mutual access between the two clusters

To enable the two clusters to access each other, you must set rules for accessing the security groups of the two clusters.

On the configuration page of the m1c1-sg group, create a rule to allow the access from m1c2-sg. For more information, see Add a security group rule.
On the configuration page of the m1c2-sg group, create a rule to allow the access from m1c1-sg.

Step 3: Add the two clusters to the ASM instance and deploy an ingress gateway

The two clusters can access each other. After you add the two clusters to the ASM instance, you only need to deploy an ingress gateway for one of the two clusters.

Add the two clusters to the ASM instance. For more information, see Add a cluster to an ASM instance.
Deploy an ingress gateway for the m1c1 cluster. For more information, see Create an ingress gateway service.

Step 4: Deploy the Bookinfo application

ASM allows you to deploy an application across clusters. You can deploy the microservices of the Bookinfo application in the two clusters.

Deploy the Bookinfo application excluding the v3 version of the reviews microservice in the m1c2 cluster. For more information, see Deploy an application in an ASM instance.

Note

The v3 version of the reviews microservice displays ratings as red stars.

The following code shows the content of the YAML file:

##################################################################################################
# Details service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: details
  labels:
    app: details
    service: details
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: details
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-details
  labels:
    account: details
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: details-v1
  labels:
    app: details
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: details
      version: v1
  template:
    metadata:
      labels:
        app: details
        version: v1
    spec:
      serviceAccountName: bookinfo-details
      containers:
      - name: details
        image: docker.io/istio/examples-bookinfo-details-v1:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Ratings service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: ratings
  labels:
    app: ratings
    service: ratings
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: ratings
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-ratings
  labels:
    account: ratings
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: ratings-v1
  labels:
    app: ratings
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ratings
      version: v1
  template:
    metadata:
      labels:
        app: ratings
        version: v1
    spec:
      serviceAccountName: bookinfo-ratings
      containers:
      - name: ratings
        image: docker.io/istio/examples-bookinfo-ratings-v1:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Reviews service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: reviews
  labels:
    app: reviews
    service: reviews
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: reviews
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-reviews
  labels:
    account: reviews
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v1
  labels:
    app: reviews
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v1
  template:
    metadata:
      labels:
        app: reviews
        version: v1
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v1:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v2
  labels:
    app: reviews
    version: v2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v2
  template:
    metadata:
      labels:
        app: reviews
        version: v2
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v2:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
# ---
# apiVersion: apps/v1
# kind: Deployment
# metadata:
#   name: reviews-v3
#   labels:
#     app: reviews
#     version: v3
# spec:
#   replicas: 1
#   selector:
#     matchLabels:
#       app: reviews
#       version: v3
#   template:
#     metadata:
#       labels:
#         app: reviews
#         version: v3
#     spec:
#       serviceAccountName: bookinfo-reviews
#       containers:
#       - name: reviews
#         image: docker.io/istio/examples-bookinfo-reviews-v3:1.15.0
#         imagePullPolicy: IfNotPresent
#         ports:
#         - containerPort: 9080
---
##################################################################################################
# Productpage services
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: productpage
  labels:
    app: productpage
    service: productpage
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: productpage
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-productpage
  labels:
    account: productpage
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: productpage-v1
  labels:
    app: productpage
    version: v1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: productpage
      version: v1
  template:
    metadata:
      labels:
        app: productpage
        version: v1
    spec:
      serviceAccountName: bookinfo-productpage
      containers:
      - name: productpage
        image: docker.io/istio/examples-bookinfo-productpage-v1:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---

Deploy the v3 version of the reviews microservice and the rating microservice on which the reviews microservice depends in the m1c1 cluster.

The following code shows the content of the YAML file:

##################################################################################################
# Reviews service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: reviews
  labels:
    app: reviews
    service: reviews
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: reviews
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: bookinfo-reviews
  labels:
    account: reviews
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: reviews-v3
  labels:
    app: reviews
    version: v3
spec:
  replicas: 1
  selector:
    matchLabels:
      app: reviews
      version: v3
  template:
    metadata:
      labels:
        app: reviews
        version: v3
    spec:
      serviceAccountName: bookinfo-reviews
      containers:
      - name: reviews
        image: docker.io/istio/examples-bookinfo-reviews-v3:1.15.0
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 9080
---
##################################################################################################
# Ratings service
##################################################################################################
apiVersion: v1
kind: Service
metadata:
  name: ratings
  labels:
    app: ratings
    service: ratings
spec:
  ports:
  - port: 9080
    name: http
  selector:
    app: ratings

Step 5: Define a virtual service and an Istio gateway

In the namespace that is named default of the ASM instance, define a virtual service that is named bookinfo. For more information, see Use Istio resources to route traffic to different versions of a service.

The following code shows the content of the YAML file:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: bookinfo
spec:
  hosts:
  - "*"
  gateways:
  - bookinfo-gateway
  http:
  - match:
    - uri:
        exact: /productpage
    - uri:
        prefix: /static
    - uri:
        exact: /login
    - uri:
        exact: /logout
    - uri:
        prefix: /api/v1/products
    route:
    - destination:
        host: productpage
        port:
          number: 9080

In the namespace that is named default of the ASM instance, define an Istio gateway that is named bookinfo-gateway. For more information, see Use Istio resources to route traffic to different versions of a service.
The following code shows the content of the YAML file:
```
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:
    - "*"
```

You can refresh the product page to view the effect of the three versions of the reviews microservice in turn. The v3 version of the reviews microservice can take effect normally though it does not reside in the same cluster as other microservices.

Step 6: Make the v3 version of the reviews microservice take effect all the time (Optional)

You can define a destination rule and a virtual service to set a policy for deploying the microservices of the Bookinfo application. The following example specifies that the v3 version of the reviews microservice always takes effect.

In the namespace that is named default of the ASM instance, define a destination rule that is named reviews.

The following code shows the content of the YAML file:

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: reviews
spec:
  host: reviews
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2
  - name: v3
    labels:
      version: v3

In the namespace that is named default of the ASM instance, define a virtual service that is named reviews.

The following code shows the content of the YAML file:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v3

When you access the product page, the v3 version of the reviews microservice takes effect all the time. In this case, ratings are displayed as red stars.