Istio-流量控制

场景1: 客户端 将流量分配到不同服务

virtual service 分配流量

使用busybox 客户端 流量通过vs 按照8比2分配到服务httpd和服务tomcat

yaml

• client
• deployment
• svc
• vs

client.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: client
  namespace: xxm
spec:
  replicas: 1 # pod数量
  selector:
    matchLabels: # pod 选择器
      app: client
  template:
    metadata:
      labels: # 定义 label 以供 Pod 选择器选择
        app: client
    spec:
      containers:
        - name: busybox
          image: busybox
          imagePullPolicy: IfNotPresent
          command: ["/bin/sh","-c","sleep 3600"]

deployment

# Deployment
apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpd
  namespace: xxm
  labels:
    server: httpd
    app: web
spec:
  replicas: 1 # pod数量
  selector:
    matchLabels: # pod 选择器
      server: httpd
      app: web
  template:
    metadata:
      name: httpd
      labels: # 定义 label 以供 Pod 选择器选择
        server: httpd
        app: web
    spec:
      containers:
        - image: busybox
          imagePullPolicy: IfNotPresent
          name: busybox # pod 中的容器名称
          command: ["/bin/sh","-c","echo  'hello httpd' > /var/www/index.html;httpd -f -p 8080 -h /var/www"]


---

# tomcat
apiVersion: apps/v1
kind: Deployment
metadata:
  name: tomcat
  namespace: xxm
  labels:
    server: tomcat
    app: web
spec:
  replicas: 1 # pod数量
  selector:
    matchLabels: # pod 选择器
      server: tomcat
      app: web
  template:
    metadata:
      name: tomcat
      labels: # 定义 label 以供 Pod 选择器选择
        server: tomcat
        app: web
    spec:
      containers:
        - image: kubeguide/tomcat-app:v1
          imagePullPolicy: IfNotPresent
          name: tomcat # pod 中的容器名称

service

apiVersion: v1
kind: Service
metadata:
  name: tomcat-svc
  namespace: xxm
spec:
  ports:
    - name: tomcat
      port: 8080  # SVC 暴露的端口
      targetPort: 8080
      protocol: TCP
  selector: # pod 选择器
    server: tomcat

---
apiVersion: v1
kind: Service
metadata:
  name: httpd-svc
  namespace: xxm
spec:
  ports:
    - name: http
      port: 8080  # SVC 暴露的端口
      targetPort: 8080
      protocol: TCP
  selector: # pod 选择器
    server: httpd

---

apiVersion: v1
kind: Service
metadata:
  name: web-svc
  namespace: xxm
spec:
  ports:
    - name: http
      port: 8080  # SVC 暴露的端口
      targetPort: 8080
      protocol: TCP
  selector: # pod 选择器
    app: web

VS

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name:  web-svc-vs
  namespace: xxm
spec:
  hosts:
    - web-svc
  http:
    - route:
        - destination:
            host: tomcat-svc # 转发的目标 SVC
          weight: 20
        - destination:
            host: httpd-svc
          weight: 80

执行

在yaml目录下执行
kubectl apply -f <(istioctl kube-inject -f xxm-client.yaml)

kubectl apply -f <(istioctl kube-inject -f xxm-deploy.yaml)

kubectl apply -f xxm-svc.yaml

kubectl apply -f xxm-vs-traffic.yaml

查看端口验证是否成功启动

kubectl get endpoints -n xxm 

//httpd-svc 按照实际ip
curl 192.168.82.232:8080

//tomcat-svc 按照实际ip
curl 192.168.82.235:8080

启动成功

进入busybox验svc

kubectl exec -it -n xxm client-549d4564bf-bnpp4 -- sh

wget -q -O - http://httpd-svc:8080

wget -q -O - tomcat-svc:8080

在busybox里 vs验证流量分配

//vs 
wget -q -O - http://web-svc:8080

可以看出 大部分流量进入httpd

场景2 根据header 内容分配到相应的服务

修改virual service 如果header 有xxm进入tomcat

修改vs

vi  xxm-vs-match.yaml

# header 完全匹配key end-user = xxm 路由到tomcat
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name:  web-svc-vs
  namespace: xxm
spec:
  hosts:
    - web-svc
  http:
    - match:
        - headers:
            end-user:
              exact: xxm
#        - uri:
#            prefix: /index.html
      route:
        - destination:
            host: tomcat-svc # 转发的目标 SV
    - route:
        - destination:
            host: httpd-svc

kubectl apply -f  xxm-vs-match.yaml

进入busybox client

kubectl exec -it -n xxm client-549d4564bf-bnpp4 -- sh


wget -q -O - web-svc:8080

wget -q -O - web-svc:8080 --header 'end-user:xxm'

验证成功 只有header 里end-user:xxm 才进入tomcat