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CronJobs

CronJobs are useful for creating periodic and recurring tasks, like running backups or sending emails. CronJobs can also schedule individual tasks at a specific time or interval, such as scheduling a Job for when your cluster is likely to be idle.

For more information, see the official documentation of Kubernetes.

Prerequisites

You need to create a workspace, a project and a user (project-regular). The user must be invited to the project with the role of operator. For more information, see Create Workspaces, Projects, Users and Roles.

Create a CronJob

Step 1: Open the dashboard

Log in to the console as project-regular. Go to Jobs of a project, choose CronJobs and click Create.

Step 2: Enter basic information

Enter the basic information. You can refer to the instructions below for each field. When you finish, click Next.

  • Name: The name of the CronJob, which is also the unique identifier.

  • Alias: The alias name of the CronJob, making resources easier to identify.

  • Schedule: It runs a Job periodically on a given time-based schedule. Please see CRON for grammar reference. Some preset CRON statements are provided in KubeSphere to simplify the input. This field is specified by .spec.schedule. For this CronJob, enter */1 * * * *, which means it runs once per minute.

    TypeCRON
    Every Hour0 * * * *
    Every Day0 0 * * *
    Every Week0 0 * * 0
    Every Month0 0 1 * *
  • Advanced Settings:

    • Maximum Start Delay (s). Specified by .spec.startingDeadlineSeconds in the manifest file, this optional field represents the maximum number of seconds that a ConJob can take to start if it misses the scheduled time for any reason. CronJobs that have missed executions will be counted as failed ones. If you do not specify this field, there is no deadline for the CronJob.
    • Successful Jobs Retained. Specified by .spec.successfulJobsHistoryLimit in the manifest file, this field represents the number of successful CronJob executions to retain. This is a pointer to distinguish between explicit zero and not specified. It defaults to 3.
    • Failed Jobs Retained. Specified by .spec.failedJobsHistoryLimit in the manifest file, this field represents the number of failed CronJob executions to retain. This is a pointer to distinguish between explicit zero and not specified. It defaults to 1.
    • Concurrency Policy. Specified by .spec.concurrencyPolicy, it represents how to treat concurrent executions of a Job:
      • Run Jobs concurrently (default): Run CronJobs concurrently.
      • Skip new Job: Forbid concurrent runs and skip the next run if the previous run hasn't finished yet.
      • Skip old Job: Cancels currently running Job and replaces it with a new one.

Note

You can enable Edit YAML in the upper-right corner to see the YAML manifest of this CronJob.

Step 3: Strategy settings (Optional)

Please refer to Jobs.

Step 4: Set a Pod

  1. Click Add Container in Containers, enter busybox in the search box, and press Enter.

  2. Scroll down to Start Command and enter /bin/sh,-c,date; echo "KubeSphere!" in the box under Parameters.

  3. Click to finish setting the image and Next to continue.

    Note

    • This example CronJob prints KubeSphere. For more information about setting images, see Pod Settings.
    • For more information about Restart Policy, see Jobs.
    • You can skip Storage Settings and Advanced Settings for this tutorial. For more information, see Mount Volumes and Configure Advanced Settings in Deployments.

Step 5: Check results

  1. In the final step of Advanced Settings, click Create to finish. A new item will be added to the CronJob list if the creation is successful. Besides, you can also find Jobs under Jobs tab.

  2. Under the ConJobs tab, click this CronJob and go to the Job Records tab where you can see the information of each execution record. There are 3 successful CronJob executions as the field Successful Jobs Retained is set to 3.

  3. Click any of them and you will be directed to the Job details page.

  4. In Resource Status, you can inspect the Pod status. Click icon on the right and click icon to check the container log as shown below, which displays the expected output.

Check CronJob Details

Operations

On the CronJob details page, you can manage the CronJob after it is created.

  • Edit Information: Edit the basic information except Name of the CronJob.
  • Pause/Start: Pause or start the Cronjob. Pausing a CronJob will tell the controller to suspend subsequent executions, which does not apply to executions that already start.
  • Edit YAML: Edit the CronJob's specification in YAML format.
  • Delete: Delete the CronJob, and return to the CronJob list page.

Job records

Click the Job Records tab to view the records of the CronJob.

Metadata

Click the Metadata tab to view the labels and annotations of the CronJob.

Events

Click the Events tab to view the events of the CronJob.

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