istio快速入门

第一步：

找到对应的版本

第二步：

执行yaml文件

[root@VM-0-15-centos istio-1.5.9]# kubectl apply -f istio-1.5.9/install/kubernetes/istio-demo.yaml

第三步

等待pod都running，这里可能等待时间较长，因为要拉取镜像，如果有拉取镜像失败，可以尝试docker pull去拉取

第四步：

创建pod，这里要注意的是一个service关联了2个deployment，并且2个deployment内容并不一样，一个v1，一个v2

[root@VM-0-15-centos ~]# cat flaskapp.yaml 
apiVersion: v1
kind: Service
metadata:
  name: flaskapp
  labels:
    app: flaskapp
spec:
  selector:
    app: flaskapp
  ports:
  - name: http
    port: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: flaskapp-1
spec:
  replicas: 1
  selector:
    matchLabels:
      app: flaskapp
  template:
    metadata: 
      labels:
        app: flaskapp
        version: v1
    spec:
      containers:
      - name: flaskapp
        image: dustise/flaskapp
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: v1
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: flaskapp-2
spec:
  replicas: 1
  selector:
    matchLabels:
      app: flaskapp
  template:
    metadata:
      labels:
        app: flaskapp
        version: v2
    spec:
      containers:
      - name: flaskapp
        image: dustise/flaskapp
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: v2

[root@VM-0-15-centos ~]# kubectl apply -f flaskapp.yaml 
service/flaskapp created
deployment.apps/flaskapp-1 created
deployment.apps/flaskapp-2 created

查看pod

 

 现在我们将istio注入到pod,可以看到istio已经注入到pod当中了

部署客户端，如下：

[root@VM-0-15-centos ~]# vim sleep.yaml
kind: Service
metadata:
  name: sleep
  labels:
    app: sleep
    version: v1
spec:
  selector:
    app: sleep
    version: v1
  ports:
  - name: ssh
    port: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: sleep
spec:
  selector:
    matchLabels:
      app: sleep
      version: v1
  replicas: 1
  template:
    metadata:
      labels:
        app: sleep
        version: v1
    spec:
      containers:
      - name: sleep
        image: dustise/sleep
        imagePullPolicy: IfNotPresent

[root@VM-0-15-centos ~]# kubectl apply -f sleep.yaml 
service/sleep created
deployment.apps/sleep created

 验证服务,可以看到基本上是轮调

 接下来我们用istio来控制这2个服务的流量,我们定义一个名字为flaskapp的destinationrule，它利用Pod标签把flaskapp服务分成两个subset，分别为v1和v2

[root@VM-0-15-centos ~]# cat flaskapp-destinationrule.yaml 
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: flaskapp
spec:
  host: flaskapp
  subsets:
  - name: v1
    labels:
      version: v1
  - name: v2
    labels:
      version: v2

[root@VM-0-15-centos ~]# kubectl apply -f flaskapp-destinationrule.yaml 
destinationrule.networking.istio.io/flaskapp created

接下来就需要为flaskapp服务创建默认规则，不论是否进行进一步的流量控制，我们都应该给它创建默认路由，以防止发生意料之外的访问结果

如下：我们定义的规则为凡是访问flaskapp这个主机的都交给v2这台主机做相应

[root@VM-0-15-centos ~]# vim flaskapp-default-vs-v2.yaml 
kind: VirtualService
metadata:
  name: flaskapp-default-v2
spec:
  hosts:
  - flaskapp
  http:
  - route:
    - destination:
        host: flaskapp
        subset: v2

[root@VM-0-15-centos ~]# kubectl apply -f flaskapp-default-vs-v2.yaml 
virtualservice.networking.istio.io/flaskapp-default-v2 created

再次验证