k8s系列（14）--探针检测

apiVersion: v1
kind: Pod
metadata:
name: readiness-httpget-pod
namespace: default
spec:
containers:

• name: readiness-httpget-container
  image: 192.168.68.253:8253/library/nginx:latest
  imagePullPolicy: IfNotPresent
  readinessProbe:
  httpGet:
  port: 80
  path: /index1.html
  initialDelaySeconds: 1
  periodSeconds: 3
  进入容器
  kubectl exec readiness-httpget-pod -it -- /bin/sh
  exit退出
  文件已经存在，但是检测还是失败了

存活检测
apiVersion: v1
kind: Pod
metadata:
name: liveness-exec-pod
namespace: default
spec:
containers:

• name: livness-exec-container
  image: 192.168.68.253:8253/library/busybox:latest
  imagePullPolicy: IfNotPresent
  command: ["/bin/sh","-с", "touch /tmp/live ; sleep 60; rm -rf /tmp/live; sleep 3600"]
  livenessProbe:
  exec:
  command: ["test","-е","/tmp/live"]
  initialDelaySeconds: 1
  periodSeconds: 3
  不知道为什么，文件夹没删掉，又失败了，拼写错误，rm -rf没有空格，上面也是拼写失败，index1.html后面多了个I

apiVersion: v1
kind: Pod
metadata:
name: liveness-httpget-pod
namespace: default
spec:
containers:

• name: liveness-httpget-container
  image: 192.168.68.253:8253/library/nginx:latest
  imagePullPolicy: IfNotPresent
  ports:
  • name: http
    containerPort: 80
    livenessProbe:
    httpGet:
    port: http
    path: /index.html
    initialDelaySeconds: 1
    periodSeconds: 3
    timeoutSeconds: 10

kubectl exec podname -it -- rm -rf /usr/share/nginx/html/index/html

apiVersion: v1
kind: Pod
metadata:
name: probe-tcp
spec:
containers:

• name: nginx
  image: 192.168.68.253:8253/library/nginx:latest
  imagePullPolicy: IfNotPresent
  livenessProbe:
  initialDelaySeconds: 5
  timeoutSeconds: 1
  tcpSocket:
  port: 80

start/end

apiVersion: v1
kind: Pod
metadata:
name: lifecycle-demo
spec:
containers:

• name: lifecycle-demo-container
  image: 192.168.68.253:8253/library/nginx:latest
  lifecycle:
  postStart:
  exec:
  command: ["/bin/sh", "-с", "echo Hello from the poststart handler > /usr/share/message"]
  prestop:
  exec:
  command: ["/bin/sh","-с", "echo Hello from the poststop handler > /usr/share/message"]

status的值
挂起（Pending）：Pod己被Kubernetes系统接受，但有一个或者多个容器镜像尚未创建。等待时间包括调度Pod的时间和通过网络下载镜像的时间，这可能需要花点时间
运行中(Running）：该Pod已经绑定到了一个节点上，Pod 中所有的容器都已被创建。至少有一个容器正在运行，或者正处于启动或重启状态
成功（Succeeded）：Pod 中的所有容器都被成功终止，并且不会再重启
失败（Failed）：Pod 中的所有容器都已终止了，并且至少有一个容器是因为失败终止。也就是说，容器以非0状态退出或者被系统终止
未知（Unknown）：因为某些原因无法取得Pod的状态，通常是因为与Pod所在主机通信失败

命令式编程：重复调用重复执行，一步一步走
声明式编程：只要最终结果一致就不会重新执行，告诉结果，自动执行，数据库就是声明式编程