kubernetes Pod容器存活性探測和就緒性探測

Pod容器存活性探測和就緒性探測

1、存活性探測

pods.spec.containers.livenessProbe.exec：存活性探測之exec探針

apiVersion: v1
kind: Pod
metadata:
  name: liveness-exec-pod
  namespace: default
spec:
  containers:
  - name: liveness-exec-container
    image: busybox:latest
    imagePullPolicy: IfNotPresent
    command: ["/bin/sh", "-c","touch /tmp/healthy; sleep 10; rm -rf /tmp/healthy; sleep 3600"]
    livenessProbe:
      exec:
        command: ["test","-e","/tmp/healthy"]  #探測命令
      initialDelaySeconds: 1  #初始化延遲時間，默認0s
      periodSeconds: 3  #隔多長時間探測一次，默認10s
      failureThreshold: 3  #探測失敗3次爲失敗，默認3次
      successThreshold: 1  #探測成功1次爲成功
  restartPolicy: Always  #探測失敗時的重啓策略
# kubectl get pods -w  #監控POD狀態
# kubectl describe pods liveness-exec-pod |grep "Restart Count"  #查看Pod重啓次數

pods.spec.containers.livenessProbe.tcpSocket：存活性探測之tcpSocket探針,探測端口是否可用

pods.spec.containers.livenessProbe.httpGet：存活性探測之httpGet探針

apiVersion: v1
kind: Pod
metadata:
  name: liveness-httpget-pod
  namespace: default
spec:
  containers:
  - name: liveness-httpget-container
    image: dongfeimg/myapp:v1
    imagePullPolicy: IfNotPresent
    ports:
    - name: http
      containerPort: 80
    livenessProbe:
      httpGet:
        port: http
        path: /index.html
      initialDelaySeconds: 1
      periodSeconds: 3
# kubectl exec -it liveness-httpget-pod -- /bin/sh  #手動連入pod
/ # rm -f /usr/share/nginx/html/index.html  #刪除index.html文件，探測失敗會重啓

2、就緒性探測

pods.spec.containers.readinessProbe.httpGet：就緒性探測之httpGet探針

apiVersion: v1
kind: Pod
metadata:
  name: readiness-httpget-pod
  namespace: default
spec:
  containers:
  - name: readiness-httpget-container
    image: dongfeimg/myapp:v1
    imagePullPolicy: IfNotPresent
    ports:
    - name: http
      containerPort: 80
    readinessProbe:
      httpGet:
        port: http
        path: /index.html
      initialDelaySeconds: 1
      periodSeconds: 3

3.啓動後和終止前鉤子

pods.spec.containers.lifecycle.preStop：終止前鉤子

pods.spec.containers.lifecycle.postStart：啓動後鉤子

apiVersion: v1
kind: Pod
metadata:
  name: poststart-pod
  namespace: default
spec:
  containers:
  - name: busybox-httpd
    image: busybox:latest
    imagePullPolicy: IfNotPresent
    lifecycle:
      postStart:
        exec:
          command: ["mkdir","-p","/data/web/html"]  #在command命令後執行此命令
    command: ["/bin/sh","-c","sleep 3600"]