Kubernetes Job与CronJob（离线业务）

Job

• Job分为普通任务（Job）  一次性执行
• 应用场景：离线数据处理，视频解码等业务

官方文档：https://kubernetes.io/docs/concepts/workloads/controllers/jobs-run-to-completion/

1、创建yaml文件

vim job.yaml

apiVersion: batch/v1

kind: Job

metadata:

  name: pi

spec:

  template:

    spec:

      containers:

      - name: pi

        image: perl

        # 计算两千位的值

        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]

      # 重启策略

      restartPolicy: Never

  # 限制重启的次数

  backoffLimit: 4

2、创建容器

kubectl create -f job.yaml

3、查看容器
kubectl get pods

NAME READY STATUS RESTARTS AGE

# 计算完成

pi-q8rvl 0/1 Completed 0 4m5s

4、执行完成后查看job
kubectl get job

NAME COMPLETIONS DURATION AGE

pi 1/1 91s 106s

5、查看日志
kubectl logs pi-q8rvl

3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513...............

6、删除方法

kubectl delete -f job.yaml

CronJob

官方文档：https://kubernetes.io/docs/tasks/job/automated-tasks-with-cron-jobs/

• 定时任务，像Linux的Crontab一样。
• 应用场景：通知，备份

1.创建一个yaml文件

vim cronjob.yaml

apiVersion: batch/v1beta1

kind: CronJob

metadata:

  name: hello

spec:

  # 分时日月周，与crontab语法一样

  schedule: "*/1 * * * *"

  # job模板

  jobTemplate:

    spec:

      template:

        spec:

          # 容器配置

          containers:

          - name: hello

            image: busybox

            # 到达时间段执行命令

            args:

            - /bin/sh

            - -c

            - date; echo Hello from the Kubernetes cluster

          # 如果异常退出就重启

          restartPolicy: OnFailure

2、创建容器

kubectl create -f cronjob.yaml 

3、查看容器
kubectl get pod

NAME READY STATUS RESTARTS AGE

hello-1566882780-t88jl 0/1 Completed 0 71s

4、查看cronjob
kubectl get cronjob

NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE

hello */1 * * * * False 0 <none> 21s

5、查看日志
kubectl logs hello-1566883020-7hw2s

Tue Aug 27 05:17:10 UTC 2019

Hello from the Kubernetes cluster

6、删除

kubectl delete -f cronjob.yaml