基于istio的VirtualService和Destination完成蓝绿和灰度发布

环境准备

• 部署 VirtualService 和Destination
  1. 通过CloudShell 连接 Kubernetes 集群。
  2. 创建并拷贝如下内容到virtual-service.yaml文件中，并执行kubectl apply -f virtual-service.yaml命令，部署 VirtualService。

     apiVersion: networking.istio.io/v1alpha3
     kind: VirtualService
     metadata:
       name: productpage
     spec:
       hosts:
       - productpage
       http:
       - route:
         - destination:
             host: productpage
             subset: v1
     ---
     apiVersion: networking.istio.io/v1alpha3
     kind: VirtualService
     metadata:
       name: reviews
     spec:
       hosts:
       - reviews
       http:
       - route:
         - destination:
             host: reviews
             subset: v1
     ---
     apiVersion: networking.istio.io/v1alpha3
     kind: VirtualService
     metadata:
       name: ratings
     spec:
       hosts:
       - ratings
       http:
       - route:
         - destination:
             host: ratings
             subset: v1
     ---
     apiVersion: networking.istio.io/v1alpha3
     kind: VirtualService
     metadata:
       name: details
     spec:
       hosts:
       - details
       http:
       - route:
         - destination:
             host: details
             subset: v1

  3. 创建并拷贝如下内容到destination.yaml文件中，并执行kubectl apply -f destination.yaml命令，部署 Destination。

     apiVersion: networking.istio.io/v1alpha3
     kind: DestinationRule
     metadata:
       name: productpage
     spec:
       host: productpage
       subsets:
       - name: v1
         labels:
           version: v1
     ---
     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
     ---
     apiVersion: networking.istio.io/v1alpha3
     kind: DestinationRule
     metadata:
       name: ratings
     spec:
       host: ratings
       subsets:
       - name: v1
         labels:
           version: v1
       - name: v2
         labels:
           version: v2
       - name: v2-mysql
         labels:
           version: v2-mysql
       - name: v2-mysql-vm
         labels:
           version: v2-mysql-vm
     ---
     apiVersion: networking.istio.io/v1alpha3
     kind: DestinationRule
     metadata:
       name: details
     spec:
       host: details
       subsets:
       - name: v1
         labels:
           version: v1
       - name: v2
         labels:
           version: v2

• 设置地址转发

  kubectl port-forward -n istio-system svc/istio-ingressgateway 3000:80

  此时，浏览器访问localhost:3000/productpage，可以看到book reviews一栏只有留言，没有评分，productpage使用的是v1版本的reviews服务。

蓝绿发布v2版本

经过前面的部署，reviews的v2版本已经在运行，现在要做的只是用蓝绿部署的方式，让v2版本上线即可。

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v2

按比例灰度发布v3版本

您可以让v2，v3版本同时在线，且两个版本各处理50%的流量。

本例中，部署完成后，多次刷新页面，可以看到book reviews一栏v2，v3版本随机出现，v3版本的评分中实心星星为红色。

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
    - reviews
  http:
  - route:
    - destination:
        host: reviews
        subset: v2
      weight: 50
    - destination:
        host: reviews
        subset: v3
      weight: 50

按http header灰度发布v3版本

只按照流量来简单的灰度还是有很多场景不能满足，您还可以按照用户来灰度，不同的用户访问不同的页面。

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: reviews
spec:
  hosts:
  - reviews
  http:
  - match:
    - headers:
        end-user:
          exact: jason
    route:
    - destination:
        host: reviews
        subset: v3
  - route:
    - destination:
        host: reviews
        subset: v2