Schedule a Job

The guides above provide examples on how to configure workloads of the type wl.Service, which is typically used for long-running web applications that should "never" go down. Alternatively, you could also schedule another kind of workload profile, namely wl.Job which corresponds to a one-off or recurring execution of tasks that run to completion and then stop.

Prerequisites

Please refer to the prerequisites in the guide for scheduling a job.

The example below also requires you to have initialized the project using the kusion workspace create and kusion init command, which will create a workspace and also generate a kcl.mod file under the stack directory.

Managing Workspace Configuration

In the first guide in this series, we introduced a step to initialize a workspace with an empty configuration. The same empty configuration will still work in this guide, no changes are required there. Alternatively, if you have updated your workspace config in the previous guides, no changes need to be made either.

Example

To schedule a job with cron expression, update simple-service/dev/main.k to the following:

simple-service/dev/main.k:

import catalog.models.schema.v1 as ac
import catalog.models.schema.v1.workload as wl
import catalog.models.schema.v1.workload.container as c

helloworld: ac.AppConfiguration {
    workload: wl.Job {
        containers: {
            "busybox": c.Container {
                # The target image
                image: "busybox:1.28"
                # Run the following command as defined
                command: ["/bin/sh", "-c", "echo hello"]
            }
        }
        # Run every minute.
        schedule: "* * * * *"
    }
}

The KCL snippet above schedules a job. Alternatively, if you want a one-time job without cron, simply remove the schedule from the configuration.

You can find the full example in here in the konfig repo.

Applying

Re-run steps in Applying and schedule the job. Your output might look like one of the following:

If you are starting from scratch, all resources are created on the spot:

$ kusion apply
 ✔︎  Generating Intent in the Stack dev...                                                                                                                                                                                                     
Stack: dev  ID                                                    Action
* ├─     v1:Namespace:simple-service                               Create
* └─     batch/v1:CronJob:simple-service:simple-service-dev-helloworld  Create


? Do you want to apply these diffs? yes
Start applying diffs ...
 SUCCESS  Create v1:Namespace:simple-service success                                                                                                                                                                                              
 SUCCESS  Create batch/v1:CronJob:simple-service:helloworld-dev-helloworld success                                                                                                                                                                 
Create batch/v1:CronJob:simple-service:simple-service-dev-helloworld success [2/2] ██████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████ 100% | 0s
Apply complete! Resources: 2 created, 0 updated, 0 deleted.

If you are starting from the last guide which configures an opsRule, the output looks like the following which destroys the Deployment and Service and replace it with a CronJob:

$ kusion apply
 ✔︎  Generating Intent in the Stack dev...                                                                                                                                                                                                     
Stack: dev  ID                                                               Action
* ├─     v1:Namespace:simple-service                                      UnChanged
* ├─     batch/v1:CronJob:simple-service:simple-service-dev-helloworld     Create
* ├─     apps/v1:Deployment:simple-service:simple-service-dev-helloworld  Delete
* └─     v1:Service:simple-service:simple-service-dev-helloworld-private  Delete


? Do you want to apply these diffs? yes
Start applying diffs ...
 SUCCESS  UnChanged v1:Namespace:simple-service, skip                                                                                                                                                                                         
 SUCCESS  Delete apps/v1:Deployment:simple-service:simple-service-dev-helloworld success                                                                                                                                                      
 SUCCESS  Create batch/v1:CronJob:simple-service:simple-service-dev-helloworld success                                                                                                                                                         
 SUCCESS  Delete v1:Service:simple-service:simple-service-dev-helloworld-private success                                                                                                                                                      
Delete v1:Service:simple-service:simple-service-dev-helloworld-private success [4/4] ███████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████ 100% | 0s
Apply complete! Resources: 1 created, 0 updated, 2 deleted.

Validation

We can verify the job has now been scheduled:

$ kubectl get cronjob -n simple-service
NAME                       SCHEDULE    SUSPEND   ACTIVE   LAST SCHEDULE   AGE
simple-service-dev-helloworld   * * * * *   False     0        <none>          2m18s

Verify the job has been triggered after the minute mark since we scheduled it to run every minute:

$ kubectl get job -n simple-service
NAME                                COMPLETIONS   DURATION   AGE
simple-service-dev-helloworld-28415748   1/1           5s         11s