destinationrule-demoapp.yaml

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: demoapp
spec:
  host: demoapp
  trafficPolicy:
    loadBalancer:
      simple: LEAST_CONN
  subsets:
  - name: v10
    labels:
      version: v1.0
    trafficPolicy:
      loadBalancer:
        consistentHash:
          httpHeaderName: X-User
  - name: v11
    labels:
      version: v1.1

virutalservice-demoapp.yaml

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: demoapp
spec:
  hosts:
  - demoapp
  http:
  - name: canary
    match:
    - uri:
        prefix: /canary
    rewrite:
      uri: /
    route:
    - destination:
        host: demoapp
        subset: v11
  - name: default
    route:
    - destination:
        host: demoapp
        subset: v10

更新demoapp dr

# kubectl apply -f destinationrule-demoapp.yaml  -f virutalservice-demoapp.yaml
destinationrule.networking.istio.io/demoapp configured
virtualservice.networking.istio.io/demoapp configured

访问demoapp

访问v10子集

root@client # curl demoapp:8080
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-hq957, ServerIP: 172.20.44.206!
root@client # curl demoapp:8080
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!

root@client # curl -H "x-user: user2" demoapp:8080
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!

root@client # curl -H "x-user: user3" demoapp:8080
iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-hq957, ServerIP: 172.20.44.206!

访问v11子集

root@client # curl demoapp:8080/canary
iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-sn9qp, ServerIP: 172.20.154.253!
root@client # curl demoapp:8080/canary
iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-sn9qp, ServerIP: 172.20.154.253!
root@client # curl demoapp:8080/canary
iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-sn9qp, ServerIP: 172.20.154.253!
root@client # curl demoapp:8080/canary
iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!

参考文档

https://istio.io/latest/zh/docs/reference/config/networking/destination-rule/#LoadBalancerSettings