測試環境：
svc: nginx
deployment: nginx-web-de1 nginx-web-de2
gateway: nginx-gateway
Virtualservice: nginx-virtual
DestinationRule: nginx

一、先可以訪問，正常工作（訪問gateway的時候能夠跳轉到nginx的POD）
1.創建svc和deployment,一個svc引用兩個deployment，規則在virtualservice配置，比如v1百分之20，v2百分之80，或者根據cookie、user、ip等訪問v1或者v2

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: http
  selector:
    app: nginx-web-de
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx-web-de1
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx-web-de
        version: v1
    spec:
      containers:
      - name: nginx
        image: nginx:v1
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: nginx-web-de2
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx-web-de
        version: v2
    spec:
      containers:
      - name: nginx
        image: nginx:v2
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 80
 

2.創建的gateway是通過api到etcd中，然後istio-ingressgateway的實例獲取，這個就相當於treafic或者nginx-ingress，然後直接訪問istio-ingressgateway

apiVersion: networking.istio.io/v1alpha3
kind: Gateway
metadata:
  name: nginx-gateway
spec:
  selector:
    istio: ingressgateway # use istio default controller
  servers:
  - port:
      number: 80
      name: http
      protocol: HTTP
    hosts:
    - "*"
 

2.創建virtualservice，綁定到gateway，可以想像成nginx的虛擬主機，訪問的ip地址想象成istio-gateway

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: nginx-virtual
spec:
  hosts:
  - "*"
  gateways:
  - nginx-gateway
  http:
  - match:
    - uri:
        exact: /nginx/
    route:
    - destination:
        host: nginx.default.svc.cluster.local
        port:
          number: 80

3.修改ingressgateway的訪問吧方式
kubectl edit svc/istio-ingressgateway -n istio-system 改成NodePort
curl 192.168.99.100:31380/nginx/ 這樣的話就是nginx-web-de1和nginx-web-de2 負載均衡，一次111一次222
docker鏡像就是簡單的 創建 nginx/index.html目錄，然後v1是"111",v2是"222",

----------------------------------------------------PS：功能實現只是能夠訪問-------------------------------------------------------------------------
我學習istio的主要要求就是 A/B test或者金絲雀發布
（1）金絲雀：利用分流 ，比如新上v2之後，我只把百分之5的流量給v2，其余還是訪問v1，根據數據分析，用戶反饋在加大流量訪問
（2）AB 根據cookie、ip、user等引流，訪問定義的版本

二、利用istio把v1百分之20 v2百分之80
1.添加DestinationRule
iapiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: nginx
spec:
host: nginx.default.svc.cluster.local
subsets:

• name: v1
  labels:
  version: v1
• name: v2
  labels:
  version: v2
  2.更改virtualservice

  
  apiVersion: networking.istio.io/v1alpha3
  kind: Gateway
  metadata:
  name: nginx-gateway
  spec:
  selector:
  istio: ingressgateway # use istio default controller
  servers:

• port:
  number: 80
  name: http
  protocol: HTTP
  hosts:

  • "*"

    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
    name: nginx-virtual
    spec:
    hosts:

• "*"
  "nginxgateway.yaml" 41L, 753C
  hosts:
  apiVersion: networking.istio.io/v1alpha3
  kind: Gateway
  metadata:
  name: nginx-gateway
  spec:
  selector:
  istio: ingressgateway # use istio default controller
  servers:
• port:
  number: 80
  name: http
  protocol: HTTP
  hosts:

  • "*"

    apiVersion: networking.istio.io/v1alpha3
    kind: VirtualService
    metadata:
    name: nginx-virtual
    spec:
    hosts:

• "*"
  "nginxgateway.yaml" 41L, 753C
  spec:
  hosts:
• "*"
  gateways:
• nginx-gateway
  http:
• match:
  • uri:
    exact: /nginx/
    route:
  • destination:
    host: nginx.default.svc.cluster.local
    port:
    number: 80
    subset: v1
    weight: 30
  • destination:
    host: nginx.default.svc.cluster.local
    port:
    number: 80
    subset: v2
    weight: 70

    
    3.更改replace的配置
    istioctl replace -f nginxgateway.yaml

4.再次訪問的時候就是十次只有兩次到v1，virtualserver的規則可以自己隨便修改，證明配置是否生效

istio 0.8 TLS 簡單測試