All Products
Search
Document Center

Container Service for Kubernetes:Create a CronJob

Last Updated:Dec 04, 2023

CronJobs are used to create periodic and recurring tasks. For example, you can create CronJobs to perform backup operations or send emails. Jobs are used to process short-lived, one-off tasks. A CronJob creates one or more Jobs based on a specific schedule. This topic describes how to create a CronJob.

Create a CronJob in the ACK console

Create a CronJob from an image

  1. Log on to the ACK console.

  2. In the left-side navigation pane of the ACK console, click Clusters.

  3. On the Clusters page, find the cluster that you want to manage and click the name of the cluster or click Details in the Actions column. The details page of the cluster appears.

  4. In the left-side navigation pane of the details page, choose Workloads > CronJobs.

  5. On the CronJobs page, click Create from Image in the upper-right corner.

  6. Set parameters for the CronJob.

    1. On the Basic Information wizard page, configure the basic settings. For more information, see Step 5: Configure basic settings.

    2. On the Container wizard page, configure one or more containers. For more information about the parameters, see Container configurations.

    3. On the Advanced wizard page, configure the advanced settings.

      Category

      Parameter

      Description

      CronJobs

      Schedule

      You can specify a schedule on an hourly, daily, weekly, or monthly basis. You can also specify a cron expression.

      For more information, see Cron Expressions.

      Concurrency Policy

      You can select one of the following concurrency polices:
      • Allow: allows Jobs to run concurrently. Concurrent Jobs compete for cluster resources.
      • Forbid: disallows Jobs to run concurrently. If a Job is not complete within the schedule, the next Job is skipped.
      • Replace: If a Job is not complete within the schedule, the Job is skipped.

      Job History

      You can specify the numbers of successful or failed Jobs for which you want to retain records. If you set the parameters to 0, the system does not retain the records of Jobs.

      Job Settings

      Completions

      For more information about how to set parameters in the Job Settings section, see Job settings.

      Parallelism

      Timeout

      BackoffLimit

      Restart

      Labels, Annotations

      Pod Labels

      You can add labels to pods in key-value pairs.

      Note

      The key of a label must be 1 to 253 characters in length, and can contain only letters, digits, hyphens (-), underscores (_), and periods (.).

      Pod Annotations

      You can add annotations to pods in key-value pairs.

      Note

      The key of an annotation must be 1 to 253 characters in length, and can contain only letters, digits, hyphens (-), underscores (_), and periods (.).

  7. Click Create.

    After the CronJob is created, you can view the CronJob on the CronJobs page.

Create a CronJob from a YAML template

  1. On the CronJobs page, click Create from YAML in the upper-right corner.

  2. On the Create page, configure the DaemonSet in the Template section.

  3. Click Create.

Create a CronJob by using kubectl

Before you use kubectl to create a CronJob, you need to create a cluster, download kubectl, and then use the kubectl client to connect to the cluster. For more information, see Obtain the kubeconfig file of a cluster and use kubectl to connect to the cluster.

The following table describes the key parameters that are used to create a CronJob.

Parameter

Description

.spec.schedule

Specifies the schedule of the CronJob. For more information about the schedule format, see Cron schedule.

.spec.jobTemplate

Specifies the type of Job to be run. For more information about Job types, see Job patterns.

.spec.startingDeadlineSeconds

Specifies the due time before which a Job must be run.

.spec.concurrencyPolicy

Specifies the concurrency policy. Valid values: Allow, Forbid, and Replace.

  • Allow: allows Jobs to run concurrently. Concurrent Jobs compete for cluster resources.

  • Forbid: disallows Jobs to run concurrently. If a Job is not complete within the schedule, the next Job is skipped.

  • Replace: If a Job is not complete within the schedule, the Job is skipped.

A CronJob named hello is created in this example to demonstrate how to create a CronJob by using kubectl.

  1. Create a file named cronjob.yaml and copy the following content into the file:

    apiVersion: batch/v1
    kind: CronJob
    metadata:
      name: hello
    spec:
      schedule: "*/1 * * * *"
      jobTemplate:
        spec:
          template:
            spec:
              containers:
              - name: hello
                image: busybox
                args:
                - /bin/sh
                - -c
                - date; echo Hello from the Kubernetes cluster
              restartPolicy: OnFailure
  2. Run the following command to create a CronJob:

    kubectl create -f cronjob.yaml

    If cronjob.batch/hello created is returned, the CronJob is created.

Related operations

After you create a CronJob, you can perform the following operations:

  • Click Details in the Actions column to view the basic information about the CronJob, including the job list and events.

  • In the Actions column, choose More > View in YAML to view the YAML content of the CronJob, choose More > Scale to modify the number of pods that run in parallel, and choose More > Delete to delete the CronJob.