Exercise

  1. Create the specification of a Job running 3 pods in sequence. Each Pod contains a single container based on the alpine:3.15 image, prints the current date in its standard output and then waits for 3 seconds

  2. Run the Job

  3. Get the logs of the 3 pods

  4. Create a CronJob that prints the current date in the standard output every minute

  5. Delete the Job and CronJob

Documentation


Solution
  1. Create a Job running 3 pods in sequence. Each Pod contains a single container based on the alpine:3.15 image, prints the current date in its standard output and then waits for 3 seconds
k create job my-job --image=alpine:3.15 --dry-run=client -o yaml -- /bin/sh -c "date && sleep 3" > job.yaml

Then modify the specification to specify 3 pods must run in sequence

apiVersion: batch/v1
kind: Job
metadata:
  name: my-job
spec: 
  parallelism: 1
  completions: 3
  template:
    spec:
      containers:
      - command:
        - /bin/sh
        - -c
        - date && sleep 3
        image: alpine:3.15
        name: my-job
      restartPolicy: Never
  1. Run the Job
k apply -f job.yaml
  1. Get the logs of the 3 pods

The name of the job is auto set as the value of the pods’ job-name label:

k logs -l job-name=my-job
  1. Create a CronJob that prints the current date in the standard output every minute
k create cronjob my-cronjob --image=alpine:3.15 --schedule="* * * * *" -- date
  1. Delete the Job and CronJob
k delete job my-job
k delete cj my-cronjob