每日一见K8s笔记(三十四)pod控制器(Job)

Job

Job主要用于负责批量处理(一次要处理指定数量的任务)短暂的一次性(每个任务仅运行一次就结束)任务，job的特点如下

• 当job创建的pod执行成功结束时，job就记录成功结束的pod数量
• 当成功结束的pod达到指定的数量时，job将完成执行

job的资源清单文件

关于重启策略设置的说明

OnFailure，则job会在pod出现故障时重启容器，而不是创建pod，failed次数不变

Never，则job会在pod出现故障时创建新的pod，并且故障pod不会消失，也不会重启，failed次数加1

Always，就意味着一直重启，意味着job任务会重复执行，这当然是不会的，所以不能设置为Always。

创建pc-job.yaml

apiVersion: batch/v1
kind: Job
metadata:
 name: pc-job
 namespace: dev
spec:
 manualSelector: true
 selector:
  matchLabels:
   app: counter-pod
 template:
  metadata:
   labels:
    app: counter-pod
  spec:
   restartPolicy: Never
   containers:
   - name: counter
     image: busybox:1.30
     command: ["bin/sh","-c","for i in 9 8 7 6 5 4 3 2 1;do echo $i;sleep 3;done"]

# 创建job
kubectl create -f pc-job.yaml

# 查看job
kubectl get job -n dev -o wide -w

NAME     COMPLETIONS   DURATION   AGE   CONTAINERS   IMAGES         SELECTOR
pc-job   1/1           52s        57s   counter      busybox:1.30   app=counter-pod

#查看pod的状态，Completed表示pod已经成功执行并已完成
[root@master ~]# kubectl get pod -n dev -w
NAME                     READY   STATUS      RESTARTS   AGE
pc-job-46tsm             0/1     Completed   0          2m33s

#删除pod
kubectl delete -f pc-job.yaml

修改pc-job.yaml,增加completions: 6和parallelism: 3

apiVersion: batch/v1
kind: Job
metadata:
 name: pc-job
 namespace: dev
spec:
 manualSelector: true
 completions: 6
 parallelism: 3
 selector:
  matchLabels:
   app: counter-pod
 template:
  metadata:
   labels:
    app: counter-pod
  spec:
   restartPolicy: Never
   containers:
   - name: counter
     image: busybox:1.30
     command: ["bin/sh","-c","for i in 9 8 7 6 5 4 3 2 1;do echo $i;sleep 3;done"]

#创建job
kubectl create -f pc-job

#查看job变化信息
kubectl get job -n dev -o wide -w
NAME     COMPLETIONS   DURATION   AGE   CONTAINERS   IMAGES         SELECTOR
pc-job   0/6           12s        12s   counter      busybox:1.30   app=counter-pod
pc-job   1/6           29s        29s   counter      busybox:1.30   app=counter-pod
pc-job   2/6           29s        29s   counter      busybox:1.30   app=counter-pod
pc-job   3/6           29s        29s   counter      busybox:1.30   app=counter-pod
pc-job   4/6           58s        58s   counter      busybox:1.30   app=counter-pod
pc-job   5/6           58s        58s   counter      busybox:1.30   app=counter-pod
pc-job   6/6           58s        58s   counter      busybox:1.30   app=counter-pod

#查看pod变化信息，三个组三个一组在运行
kubectl get pod -n dev -w
pc-job-dk77g             0/1     Pending       0          0s
pc-job-jpfkd             0/1     Pending       0          0s
pc-job-twfmw             0/1     Pending       0          0s
pc-job-dk77g             0/1     Pending       0          0s
pc-job-jpfkd             0/1     Pending       0          0s
pc-job-twfmw             0/1     Pending       0          0s
pc-job-dk77g             0/1     ContainerCreating   0          0s
pc-job-jpfkd             0/1     ContainerCreating   0          0s
pc-job-twfmw             0/1     ContainerCreating   0          0s
pc-job-jpfkd             1/1     Running             0          2s
pc-job-twfmw             1/1     Running             0          2s
pc-job-dk77g             1/1     Running             0          2s        

#删除job
kubectl delete -f pc-job

注意：非原创，是跟着黑马视频学习一个字一个字敲出来的笔记

视频地址：

https://www.bilibili.com/video/BV1xX4y1K7nb?p=2