쿠버1탄-12. 쿠버네티스 - jobs,cronjob

다음은 쿠버네티스 스터디 자료를 참고해 정리한 내용입니다.

<1> job = 단일로 수행하는 것

<2> cronjob = 일정 주기로 실행

<3> 삭제

<4> 정리

<5> 다음 과정

<1> job = 단일로 수행하는 것

1

특정 동작을 수행하고 종료하는 작업용 오브젝트

2

접속,정리

ssh -i ~/.ssh/id_rsa ubuntu@api.k8s.serverchk.com

kubectl delete pod --all

3

파이 소수점 계산하기

cat << EOF > job.yaml

apiVersion: batch/v1

kind: Job

metadata:

name: pi

spec:

template:

spec:

containers:

- name: pi

image: perl

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

restartPolicy: Never

backoffLimit: 4

EOF

110 job.txt

3

터미널2에서 모니터링

watch -d 'kubectl get pods,jobs -o wide'

4

kubectl apply -f job.yaml && kubectl get pods -w

ubuntu@ip-172-20-41-255:~$ kubectl apply -f job.yaml && kubectl get pods -w

job.batch/pi created

NAME READY STATUS RESTARTS AGE

pi-pw6tf 0/1 ContainerCreating 0 0s

pi-pw6tf 0/1 ContainerCreating 0 0s

pi-pw6tf 1/1 Running 0 19s

pi-pw6tf 0/1 Completed 0 23s

pi-pw6tf 0/1 Completed 0 23s

모니터링

Every 2.0s: kubectl get pods,jobs -o wide ip-172-20-41-255: Fri Jul 2 04:48:46 2021

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

pod/pi-pw6tf 0/1 Completed 0 54s 100.98.158.185 ip-172-20-38-144.ap-northeast-1.compute.internal <none> <none>

NAME COMPLETIONS DURATION AGE CONTAINERS IMAGES SELECTOR

job.batch/pi 1/1 23s 54s pi perl controller-uid=63096c24-5805-4e50-bb53-0cf0e060cc72

5

결과 log로 확인

kubectl logs -l job-name=pi

// 3.141592 ....... 파이에 대한 값이 나온다.

3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798214808651328230664709384460955058223172535940812848111745028410270193852110555964462294895493038196442881097566593344612847564823378678316527120190914564856692346034861045432664821339360726024914127372458700660631558817488152092096282925409171536436789259036001133053054882046652138414695194151160943305727036575959195309218

6

kubectl get jobs.batch pi -o wide

NAME COMPLETIONS DURATION AGE CONTAINERS IMAGES SELECTOR

pi 1/1 23s 110s pi perl controller-uid=63096c24-5805-4e50-bb53-0cf0e06

상세

kubectl describe jobs.batch pi

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal SuccessfulCreate 2m23s job-controller Created pod: pi-pw6tf

Normal Completed 2m job-controller Job completed

7

pod name 으로 조회 pi-pw6tf

kubectl get pod pi-pw6tf

NAME READY STATUS RESTARTS AGE

pi-pw6tf 0/1 Completed 0 5m28s

8

kubectl describe pod pi-pw6tf

ubuntu@ip-172-20-41-255:~$ kubectl describe pod pi-pw6tf

Name: pi-pw6tf

Namespace: default

Priority: 0

Node: ip-172-20-38-144.ap-northeast-1.compute.internal/172.20.38.144

Start Time: Fri, 02 Jul 2021 04:47:52 +0000

Labels: controller-uid=63096c24-5805-4e50-bb53-0cf0e060cc72

job-name=pi

Annotations: cni.projectcalico.org/podIP:

cni.projectcalico.org/podIPs:

kubernetes.io/limit-ranger: LimitRanger plugin set: cpu request for container pi

Status: Succeeded

IP: 100.98.158.185

:

Events:

Type Reason Age From Message

---- ------ ---- ---- -------

Normal Scheduled 6m2s default-scheduler Successfully assigned default/pi-pw6tf to ip-172-20-38-144.ap-northeast-1.compute.internal

Normal Pulling 6m2s kubelet Pulling image "perl"

Normal Pulled 5m45s kubelet Successfully pulled image "perl" in 16.323738814s

Normal Created 5m44s kubelet Created container pi

Normal Started 5m44s kubelet Started container pi

kubectl describe pod

9

한번 더 실행하면?

kubectl apply -f https://kubernetes.io/examples/controllers/job.yaml

ubuntu@ip-172-20-41-255:~$ kubectl apply -f https://kubernetes.io/examples/controllers/job.yaml

job.batch/pi unchanged

// 변화 없다.

Pod가 이미 셀렉터를 가지고 있는 레이블 값은 Pos가 가지고 있다.

이미 끝난 값이라 변화가 없다.

kubectl get jobs.batch pi -o wide

NAME COMPLETIONS DURATION AGE CONTAINERS IMAGES SELECTOR

pi 1/1 23s 110s pi perl controller-uid=63096c24-5805-4e50-bb53-0cf0e06

10

kubectl delete -f https://kubernetes.io/examples/controllers/job.yaml

<2> cronjob = 일정 주기로 실행

1

현재 시간, hello를 1분 마다 실행해 보자

date 시간을 기준으로 동작 한다.

date

Tue Oct 5 07:43:40 UTC 2021

2

clear

cat << EOF > cronjob.yaml

apiVersion: batch/v1beta1

kind: CronJob

metadata:

name: hello

spec:

schedule: "*/1 * * * *" # 매 1분마다 실행

successfulJobsHistoryLimit: 10 # 성공 Job 10개 까지 기록

jobTemplate: # 실행될 Job 내용

spec:

template:

spec:

containers:

- name: hello

image: busybox

imagePullPolicy: IfNotPresent

command:

- /bin/sh

- -c

- date; echo Hello from the DKOS Member!

restartPolicy: OnFailure

EOF

120 cronjob.txt

3

kubectl apply -f cronjob.yaml && kubectl get jobs --watch

error: unable to recognize "cronjob.yaml": no matches for kind "CronJob" in version "batch/v1"

4

kubectl get pod

NAME READY STATUS RESTARTS AGE

hello-1625202360-vbf57 0/1 Completed 0 24s

모니터링

Every 2.0s: kubectl get pods,jobs -o wide ip-172-20-41-255: Fri Jul 2 05:06:43 2021

NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES

pod/hello-1625202360-vbf57 0/1 Completed 0 35s 100.98.158.181 ip-172-20-38-144.ap-northeast-1.compute.internal <none> <none>

NAME COMPLETIONS DURATION AGE CONTAINERS IMAGES SELECTOR

job.batch/hello-1625202360 1/1 1s 35s hello busybox controller-uid=9ddac269-bbcd-47fd-a74a-0bf57f668776

5

kubectl get cronjobs.batch

NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE

hello */1 * * * * False 0 56s 94s

6

kubectl get jobs.batch

NAME COMPLETIONS DURATION AGE

hello-1625202360 1/1 1s 71s

hello-1625202420 1/1 1s 11s

7

watch -n 1 "kubectl logs -l job-name"

Fri Jul 2 05:06:09 UTC 2021

Hello from the DKOS Member!

Fri Jul 2 05:07:09 UTC 2021

Hello from the DKOS Member!

8

결과 확인 !!!

kubectl logs -l job-name

Fri Jul 2 05:06:09 UTC 2021

Hello from the DKOS Member!

Fri Jul 2 05:07:09 UTC 2021

Hello from the DKOS Member!

// 1분 마다 1번씩 찍힘!!

<3> 삭제

kubectl delete -f cronjob.yaml

cronjob.batch "hello" deleted

<4> 정리

1

job = 단일로 수행하는 것

2

cronjob = 일정 주기로 실행

<5> 다음 과정

https://brunch.co.kr/@topasvga/1681

실습1-13.도메인 없이 KOPS로 AWS에 쿠버네티스

https://brunch.co.kr/@topasvga/1656

(몰아보기) 쿠버네티스 전문가 되기-2022

감사합니다.