Kubernetes-健康状态检查

目录

• livenessProbe

• readinessprobe
  说明：健康状态对POD的服务（端口TCP，HTTP协议）进行检查，保证APP高可用

• 健康检查--重启POD

1.livenessProbe：  健康检查失败，重启pod解决问题
failureThreshold # 失败最大次数  3
initialDelaySeconds # POD启动之后， 延时多少才进行检测 
periodSeconds 5 #  多少秒钟检查一次
successThreshold  2 # 连续成功多次检查 认为健康检查成功 
timeoutSeconds 10 #会话超时时间

1. POD启用livenessProbe，检查POD健康状态

trnuser@k8s:~/pod/dc$ cat dc1.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: dc2
  name: dc2
spec:
  replicas: 2
  selector:
    matchLabels:
      app: dc2
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dc2
    spec:
      containers:
      - image: nginx
        name: nginx
        livenessProbe:
          httpGet:
            path: /index.html
            port: 80
            scheme: HTTP
        imagePullPolicy: IfNotPresent
        resources: 
          requests:
            cpu: 400m
status: {}

• 添加参数

trnuser@k8s:~/pod/dc$ cat dc-liveness.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: dc2
  name: dc2
spec:
  replicas: 2
  selector:
    matchLabels:
      app: dc2
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dc2
    spec:
      containers:
      - image: nginx
        name: nginx
        livenessProbe:
          failureThreshold: 3
          initialDelaySeconds: 10
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 10
          httpGet:
            path: /index.html
            port: 80
            scheme: HTTP
        imagePullPolicy: IfNotPresent
        resources: 
          requests:
            cpu: 400m
status: {}

• 健康检查--不重启POD，从SVC中删除

2. readinessprobe
   会从SVC中删除，但不会重建POD，若replica==2，会变为单点

trnuser@k8s:~/pod/dc$ cat dc-liveness.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: dc2
  name: dc2
spec:
  replicas: 2
  selector:
    matchLabels:
      app: dc2
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dc2
    spec:
      containers:
      - image: nginx
        name: nginx
        readinessProbe:  #  POD应答策略
          failureThreshold: 3
          initialDelaySeconds: 10
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 10
          httpGet:
            path: /index.html
            port: 80
            scheme: HTTP
        imagePullPolicy: IfNotPresent
        resources: 
          requests:
            cpu: 400m
status: {}