ALBERT SITE

[k8s] job,cronjob

Posted by Albert 106Day 18Hour 11Min 57Sec ago [2025-04-22]

1. JOB

쿠버네티스에서 잡은 쿠버네티스 애플리케이션의 실행 및 종료에 초점을 맞춘 리소스유형

(잡을 활용하면 파드를 생성하고 지정된 수의 파드가 성공적으로 종료될때까지 계속해서 파드의 실행을 재시도하고, 지정된 수의 성공횟수가 완료횟수에 도달하면 잡이 종료됨)

albert@k8s-master:~/work/ch09/ex15$ vi job-cronjob01.yml

apiVersion: batch/v1
kind: Job
metadata:
  name: job-test01
spec:
  template:
    spec:
      containers:
      - name: nginx-test01
        image: nginx:1.25
        command: ["echo", "Hello, Kubernetes!"]
      restartPolicy: Never
  backoffLimit: 3

nginx-test01xxx pod 생성 하고 job 실행시 "Hello, Kubernetes!" 메세지 출력한다

albert@k8s-master:~/work/ch09/ex15$ kubectl apply -f job-cronjob01.yml
job.batch/job-test01 created
        
albert@k8s-master:~/work/ch09/ex15$ kubectl get job
NAME         COMPLETIONS   DURATION   AGE
job-test01   1/1           3s         6s

albert@k8s-master:~/work/ch09/ex15$ kubectl describe job job-test01
Name:             job-test01
Namespace:        default
Selector:         batch.kubernetes.io/controller-uid=04568748-3a2d-4c39-8017-91dc12262073
Labels:           batch.kubernetes.io/controller-uid=04568748-3a2d-4c39-8017-91dc12262073
batch.kubernetes.io/job-name=job-test01
controller-uid=04568748-3a2d-4c39-8017-91dc12262073
job-name=job-test01
Annotations:      <none>
Parallelism:      1
Completions:      1
Completion Mode:  NonIndexed
Start Time:       Tue, 22 Apr 2025 04:30:02 +0000
Completed At:     Tue, 22 Apr 2025 04:30:05 +0000
Duration:         3s
Pods Statuses:    0 Active (0 Ready) / 1 Succeeded / 0 Failed
Pod Template:
Labels:  batch.kubernetes.io/controller-uid=04568748-3a2d-4c39-8017-91dc12262073
batch.kubernetes.io/job-name=job-test01
controller-uid=04568748-3a2d-4c39-8017-91dc12262073
job-name=job-test01
Containers:
nginx-test01:
Image:      nginx:1.25
Port:       <none>
Host Port:  <none>
Command:
echo
Hello, Kubernetes!
Environment:  <none>
Mounts:       <none>
Volumes:        <none>
Events:
Type    Reason            Age   From            Message
  ----    ------            ----  ----            -------
Normal  SuccessfulCreate  23s   job-controller  Created pod: job-test01-q6j27
Normal  Completed         20s   job-controller  Job completed

albert@k8s-master:~/work/ch09/ex15$ kubectl get pod
NAME               READY   STATUS      RESTARTS   AGE
job-test01-q6j27   1/1     Completed   0          56s

albert@k8s-master:~/work/ch09/ex15$ kubectl logs job-test01-q6j27
Hello, Kubernetes!

2. CRONJOB

크론잡은 리눅스의 crontab처럼 반복적으로 잡을 만든다.

albert@k8s-master:~/work/ch09/ex15$ vi job-cronjob02.yml

apiVersion: batch/v1
kind: CronJob
metadata:
  name: cronjob-test02
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: nginx-test02
            image: nginx:1.25
            command:
            - /bin/sh
            - -c
            - echo Hello Kubernetes!
          restartPolicy: Never

매1분마다 pod 생성하는 cronjob

albert@k8s-master:~/work/ch09/ex15$ kubectl apply -f job-cronjob02.yml
cronjob.batch/cronjob-test02 created
        
albert@k8s-master:~/work/ch09/ex15$ kubectl get cronjob
NAME             SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
cronjob-test02   */1 * * * *   False     0        <none>          6s

최초 확인시 아무런 파트도 생성되지않는다.

albert@k8s-master:~/work/ch09/ex15$ kubectl describe cronjob cronjob-test02
Name:                          cronjob-test02
Namespace:                     default
Labels:                        <none>
Annotations:                   <none>
Schedule:                      */1 * * * *
Concurrency Policy:            Allow
Suspend:                       False
Successful Job History Limit:  3
Failed Job History Limit:      1
Starting Deadline Seconds:     <unset>
Selector:                      <unset>
Parallelism:                   <unset>
Completions:                   <unset>
Pod Template:
Labels:  <none>
Containers:
nginx-test02:
Image:      nginx:1.25
Port:       <none>
Host Port:  <none>
Command:
        /bin/sh
      -c
echo Hello Kubernetes!
Environment:     <none>
Mounts:          <none>
Volumes:           <none>
Last Schedule Time:  <unset>
Active Jobs:         <none>
Events:              <none>

1분후 확인시 신규 pod가 생성된거 확인 할 수 있다.

albert@k8s-master:~/work/ch09/ex15$ kubectl describe cronjob cronjob-test02
Name:                          cronjob-test02
Namespace:                     default
Labels:                        <none>
Annotations:                   <none>
Schedule:                      */1 * * * *
Concurrency Policy:            Allow
Suspend:                       False
Successful Job History Limit:  3
Failed Job History Limit:      1
Starting Deadline Seconds:     <unset>
Selector:                      <unset>
Parallelism:                   <unset>
Completions:                   <unset>
Pod Template:
Labels:  <none>
Containers:
nginx-test02:
Image:      nginx:1.25
Port:       <none>
Host Port:  <none>
Command:
        /bin/sh
      -c
echo Hello Kubernetes!
Environment:     <none>
Mounts:          <none>
Volumes:           <none>
Last Schedule Time:  Tue, 22 Apr 2025 04:34:00 +0000
Active Jobs:         <none>
Events:
Type    Reason            Age   From                Message
  ----    ------            ----  ----                -------
Normal  SuccessfulCreate  25s   cronjob-controller  Created job cronjob-test02-29088274
Normal  SawCompletedJob   22s   cronjob-controller  Saw completed job: cronjob-test02-29088274, status: Complete

끝

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