Shulou(Shulou.com)06/02 Report--

Job Resource Object

Pod containers for service classes: RC, RS, DS, Deployment.

Pod containers for work classes: Job---> execute once, or execute the processing program in batches, and push the container out after completion.

[root@master ~]# cat job.yaml

kind: Job

apiVersion: batch/v1

metadata:

name: test-job

spec:

template:

metadata:

name: test-job

spec:

containers:

name: hello

image: busybox

command: ["echo","hello k8s job! "]

restartPolicy: Never

[root@master ~]# kubectl get pod

NAME READY STATUS RESTARTS AGE

test-job-qgc6p 0/1 Completed 0 55s

[root@master ~]# kubectl logs test-job-qgc6p

hello k8s job!

PS: Note that if the task is executed incorrectly in the container, the container will be operated according to the restart policy of the container, but the restart policy of the container here can only be: Never, OnFailure

Improve Job Execution Efficiency

We can add parallelism to the Job.spec field. Indicates how many pods are running simultaneously to perform tasks

We can add the completions option to the Job.spec field. Indicates the total number of pods that need to be completed.

[root@master ~]# cat job.yaml

kind: Job

apiVersion: batch/v1

metadata:

name: test-job

spec:

completions: 8 //Total number of pods to complete

parallelism: 2 //run several pods simultaneously

template:

metadata:

name: test-job

spec:

containers:name: hello

image: busybox

command: ["echo","hello k8s job! "]

restartPolicy: OnFailure

How to perform a Job regularly

kind: CronJob

apiVersion: batch/v1beta1

metadata:

name: hello

spec:

schedule: "/1 *"

jobTemplate:

spec:

template:

spec:

containers:name: hello

image: busybox

command: ["echo","hello cronjob! "]

restartPolicy: OnFailure

[root@master ~]# kubectl apply -f cronjob.yaml

[root@master ~]# kubectl get cronjobs.batch

NAME SCHEDULE SUSPEND ACTIVE LAST SCHEDULE AGE

hello /1 * False 0 47s 51s

[root@master ~]# kubectl logs hello-1579053480-vpm6t

hello cronjob!

Looking at the status of the pods, you will see that a new Pod is running every minute to perform the tasks specified by the command.

Exercise:

Specify January 15, 2020 at 10:05 AM to run the crontab task above.

[root@master ~]# cat cronjob.yaml

kind: CronJob

apiVersion: batch/v1beta1

metadata:

name: hello

spec:

schedule: "5 10 15 1 3"

jobTemplate:

spec:

template:

spec:

containers:name: hello

image: busybox

command: ["echo","hello cronjob! "]

restartPolicy: OnFailure

At this point, it may be found that if a specific time is specified, the task may not be carried out.

[root@master ~]# kubectl api-versions //view api versions

Add the apiVersion library.

[root@master ~]# vim /etc/kubernetes/manifests/kube-apiserver.yaml

//add to yaml file

--runtime-config=batch/v2alpha1=true

Then restart the kubelet service and re-identify the api yaml file content.

//view api repository

[root@master ~]# kubectl api-versions

PS: Note that the job for the specified time still cannot run normally at this time, because k8s official has not perfected this function in the support of cronjob this resource object. Still to be developed.

Just like job resources, concurrent Job parameters are also supported under cronjob.spec.jobTemplate.spec: parallelism, and the total number of completed pods is also supported. Parameters: completions

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