k8s蓝绿部署实践

在进行蓝/绿部署时，应用程序的一个新副本（绿）将与现有版本（蓝）一起部署。然后更新应用程序的入口/路由器以切换到新版本（绿）。然后，您需要等待旧（蓝）版本来完成所有发送给它的请求，但是大多数情况下，应用程序的流量将一次更改为新版本；Kubernetes不支持内置的蓝/绿部署。目前最好的方式是创建新的部署，然后更新应用程序的服务（如service）以指向新的部署；蓝绿部署是不停老版本，部署新版本然后进行测试，确认OK后将流量逐步切到新版本。蓝绿部署无需停机，并且风险较小。

demo-blue1.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-blue1
  namespace: default
  labels:
    app: demo
    version: v1
spec:
  replicas: 1
  revisionHistoryLimit: 3
  strategy:
    rollingUpdate:
      maxSurge: 30%
      maxUnavailable: 30%
  selector:
    matchLabels:
      app: demo
      version: v1
  template:
    metadata:
      labels:
        app: demo
        version: v1
    spec:
      containers:
      - name: demo-blue1
        image:  opcache/devops-go-sample:hello1
        resources:
          limits:
            cpu: 5m
            memory: 10Mi
          requests:
            cpu: 5m
            memory: 10Mi
        livenessProbe:
          httpGet:
            path: /
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 3
          timeoutSeconds: 5
          periodSeconds: 30
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 3
          timeoutSeconds: 5
          periodSeconds: 10
          successThreshold: 1
          failureThreshold: 5
        ports:
          - name: http
            containerPort: 8080
            protocol: TCP

demo-green2.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-green2
  namespace: default
  labels:
    app: demo
    version: v2
spec:
  replicas: 1
  revisionHistoryLimit: 3
  strategy:
    rollingUpdate:
      maxSurge: 30%
      maxUnavailable: 30%
  selector:
    matchLabels:
      app: demo
      version: v2
  template:
    metadata:
      labels:
        app: demo
        version: v2
    spec:
      containers:
      - name: demo-green2
        image: opcache/devops-go-sample:hello2
        livenessProbe:
          httpGet:
            path: /
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 3
          timeoutSeconds: 5
          periodSeconds: 30
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 3
          timeoutSeconds: 5
          periodSeconds: 10
          successThreshold: 1
          failureThreshold: 5
        ports:
          - name: http
            containerPort: 8080
            protocol: TCP

Service-v1文件
Service-v1.yaml

apiVersion: v1
kind: Service
metadata:
  name: demo
  namespace: default
  labels:
    app: demo
spec:
  ports:
    - port: 8080
      targetPort: http
      protocol: TCP
      name: http
  selector:
    app: demo
    version: v1

Service-v2文件
Service-v2.yaml

apiVersion: v1
kind: Service
metadata:
  name: demo
  namespace: default
  labels:
    app: demo
spec:
  ports:
    - port: 8080
      targetPort: http
      protocol: TCP
      name: http
  selector:
    app: demo
    version: v2

执行步骤

kubectl apply -f demo-blue1.yaml
kubectl apply -f demo-green2.yaml
kubectl apply -f Service-v1.yaml
#获取SVC  IP
kubectl get rc,pods,svc,ingress --all-namespaces -o wide | grep demo

验证请求

 for i in `seq 1 100000`; do curl  10.106.49.228:8080/?a=$i ;echo " "; done

一直循环打印 Hello World1

然后执行

kubectl apply -f Service-v2.yaml

这个时候请求切换到了demo-green2
一直循环打印 Hello World2