一、探针区别

livenessProbe：健康状态检查，周期性检查服务是否存活，检查结果失败，将重启容器

readinessProbe：可用性检查，周期性检查服务是否可用，不可用将从service的endpoints中移除

探针检测方法

• exec：执行一段命令 返回值为0, 非0
• httpGet：检测某个 http 请求的返回状态码 2xx,3xx正常, 4xx,5xx错误
• tcpSocket：测试某个端口是否能够连接

二、liveness探针的exec使用

编写yaml文件

[root@k8s-master check]# cat nginx_pod_exec.yaml
iapiVersion: v1
kind: Pod
metadata:
  name: exec
spec:
  containers:
    - name: nginx
      image: 10.0.0.11:5000/nginx:1.13
      ports:
        - containerPort: 80
      args:
        - /bin/sh
        - -c
        - touch /tmp/healthy; sleep 30; rm -rf /tmp/healthy; sleep 600
      livenessProbe:
        exec:
          command:
            - cat
            - /tmp/healthy
        initialDelaySeconds: 5   
        periodSeconds: 5
        timeoutSeconds: 5
        successThreshold: 1
        failureThreshold: 1
 

 启动：

[root@k8s-master check]# kubectl create -f nginx_pod_exec.yaml 

查看：

[root@k8s-master check]# kubectl describe pod exec
-------------------

liveness探针的httpGet使用

vi   nginx_pod_httpGet.yaml 

iapiVersion: v1

kind: Pod

metadata:

  name: httpget

spec:

  containers:

    - name: nginx

      image: 10.0.0.11:5000/nginx:1.13

      ports:

        - containerPort: 80

      livenessProbe:

        httpGet:

          path: /index.html

          port: 80

        initialDelaySeconds: 3

        periodSeconds: 3

 liveness探针的tcpSocket使用

vi   nginx_pod_tcpSocket.yaml

iapiVersion: v1

kind: Pod

metadata:

  name: tcpSocket

spec:

  containers:

    - name: nginx

      image: 10.0.0.11:5000/nginx:1.13

      ports:

        - containerPort: 80

      args:

        - /bin/sh

        - -c

        - tail -f /etc/hosts

      livenessProbe:

        tcpSocket:

          port: 80

        initialDelaySeconds: 10

        periodSeconds: 3

 readiness探针的httpGet使用

vi   nginx-rc-httpGet.yaml

iapiVersion: v1

kind: ReplicationController

metadata:

  name: readiness

spec:

  replicas: 2

  selector:

    app: readiness

  template:

    metadata:

      labels:

        app: readiness

    spec:

      containers:

      - name: readiness

        image: 10.0.0.11:5000/nginx:1.13

        ports:

        - containerPort: 80

        readinessProbe:

          httpGet:

            path: /qiangge.html

            port: 80

          initialDelaySeconds: 3

          periodSeconds: 3