使用ASM Serverless网关实现多集群统一的流量入口 - 服务网格 ASM

通过阿里云服务网格ASM，您可以在同一VPC内的多个Kubernetes集群上部署应用服务组件，并配置一个统一的Serverless入口网关代理多集群的入口流量，从而提升整体服务的可用性、降低计算资源成本。

前提条件

在同一VPC下，已创建两个ACK集群（本示例为m1c1和m1c2）。具体操作，请参见创建ACK专有集群或创建。
说明
在创建集群时，建议使用企业安全组。
已创建一个ASM实例（本示例为mesh1），且版本为1.18.0.139及以上。

步骤一：确认两个集群的互访联通性

默认情况下，同一个VPC下的两个集群，如果使用了企业安全组，默认能够互相访问。如果使用普通安全组或者两个安全组访问不通，则需要为彼此添加安全组访问规则。具体操作，请参见添加安全组规则。

步骤二：添加集群到ASM实例并创建Serverless入口网关

将两个集群添加到ASM实例后，创建一个Serverless入口网关。

将两个集群添加到ASM实例。具体操作，请参见添加集群到ASM实例。

使用以下YAML，创建一个Serverless入口网关。具体操作，请参见创建入口网关服务。

展开查看Serverless入口网关YAML

apiVersion: istio.alibabacloud.com/v1beta1
kind: IstioGateway
metadata:
  annotations:
    asm.alibabacloud.com/managed-by-asm: 'true'
  name: ingressgateway
  namespace: istio-system
spec:
  gatewayType: ingress
  dnsPolicy: ClusterFirst
  externalTrafficPolicy: Local
  hostNetwork: false
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: 80
    - name: https
      port: 443
      protocol: TCP
      targetPort: 443
  replicaCount: 1
  resources:
    limits:
      cpu: '2'
      memory: 2G
    requests:
      cpu: 200m
      memory: 256Mi
  rollingMaxSurge: 100%
  rollingMaxUnavailable: 25%
  runAsRoot: true
  serviceType: LoadBalancer

步骤三：部署Bookinfo应用

为了演示ASM跨集群的应用部署能力，Bookinfo应用的不同微服务分别部署在两个集群上。

使用以下内容，在m1c2集群中创建bookinfo-m1c2.yaml。

说明

review-v3 deployment对应的功能是书评中显示红色星。

展开查看Bookinfo应用YAML

# 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
---
# 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
---

执行以下命令，在m1c2集群中部署不包含review-v3 deployment的Bookinfo应用。
```
kubectl apply -f bookinfo-m1c2.yaml
```

使用以下内容，在m1c1集群中创建bookinfo-m1c1.yaml。

展开查看YAML内容

# 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

执行以下命令，在m1c1集群中部署review-v3和ratting service。
```
kubectl apply -f bookinfo-m1c1.yaml
```

步骤四：添加虚拟服务和网关规则

在ASM实例的default命名空间下，新建一个名为bookinfo的虚拟服务。具体操作，请参见管理虚拟服务。

展开查看虚拟服务YAML

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

在ASM实例的default命名空间下，新建一个名为bookinfo-gateway的网关规则。具体操作，请参见管理网关规则。

展开查看网关规则YAML

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:
    - "*"

在浏览器地址栏，输入http://{Serverless入口网关的IP地址}/productpage，并多次刷新页面。
可以看到页面出现reviews的3个版本，且比例接近1:1:1。虽然review-v3和其他服务不在同一个集群中，也可以正常显示。

（可选）步骤五：指定reviews总是使用v3版本

通过定义目标规则和虚拟服务，可以定义Bookinfo应用的微服务部署策略。本例中将指定Bookinfo总是使用review v3版本。

在ASM实例的default命名空间下，新建一个名为reviews的目标规则。具体操作，请参见管理虚拟服务。

展开查看目标规则YAML

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

在ASM实例的default命名空间下，新建一个名为reviews的虚拟服务。具体操作，请参见管理虚拟服务。

展开查看虚拟服务YAML

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

在浏览器地址栏，输入http://{Serverless入口网关的IP地址}/productpage，并多次刷新页面。
可以看到reviews始终使用v3版本，即书评中为红色星。