Running and updating jobs

Creating a job

Create a Code Engine job by using the icr.io/codeengine/firstjob image. This job prints Hi from a batch job! My index is:.

1. Open the Code Engine Overview page.
2. Select Let's go.
3. Select Job.
4. Select a project from the list of available projects. You can also create a new one. Note that you must have a selected project to create a job.
5. Enter a name for the job and specify icr.io/codeengine/firstjob for the container image. Use a name for your job that is unique within the project. For this example, you do not need to modify the default values for environment variables or runtime settings. For more information about the code that is used for this example, see firstjob.
6. Click Create.

Running a job

After you create your job and specify your workload configuration information, you are ready to run your job. You can override some configuration information.

Note that when you run your job, the latest version of your referenced container image is downloaded and deployed, unless you specified a tag for the image. If a tag is specified for the image, then the tagged image is used for the job.

1. Navigate to your job page:

   • From the Code Engine Projects page, click the name of your project. Click Jobs to work with your jobs and job runs.
   • From the Jobs page, click the Jobs tab, and click the name of the job that you want to run.

2. From your job page, click Submit job to submit a job that is based on the current configuration.

3. From the "Submit job" pane, accept all the default values, and click Submit job again to run your job.

From the "Submit job" pane, you can review and optionally change default configuration values such as instances, CPU, memory, number of job retries, and job timeout. You can specify either Array size or Array indices for the parallel job instances to run. For Array size, provide the number of instances to run in parallel for this job. For Array indices, provide a comma-separated list for your custom set of indices. For example, to run this job with a custom set of 5 indices, specify 3,12-14,25. You can also specify a custom value for the job array size, which updates the value of the automatically injected JOB_ARRAY_SIZE environment variable. After you submit this job, the system displays the status of the instances of your job on the Job details page. If you specify Array size instead of Array indices in the"Submit job" pane, from the Configuration section of the Job details page, this information is provided as Array indices.

Accessing job details

Find details about your job.

After you submit your job, the results of the specific job run are available in the console from the Job run details page. From the console, you can also view details of your job and specific job runs from the Jobs page.

• To view job details, click the Jobs tab, and click the name of the job you want to work with.
• To view details for a specific job run, click the Job runs tab, and click the name of the job run that you want to work with.

If any of the instances of your job failed to run, you can take the following actions:

1. Click Rerun failed indices to run the job again for indices that failed. From the Submit job pane, review and optionally change the configuration values, including Array indices. The Array indices field automatically lists the indices of the failed job run instances.

2. Click Submit job to submit the job for the failed indices.

You can view job logs after you add logging capabilities. For more information, see viewing job logs from the console.

Updating a job

You can manage your job by fine tuning your job configuration, which includes updating the code container image, code arguments or commands, runtime instance resources, or environment variables.

When the job is in a ready state, you can update the job. Let's update the job that you created previously to change the container image from icr.io/codeengine/firstjob to icr.io/codeengine/testjob and then update an environment variable. When a request is sent to this icr.io/codeengine/testjob sample job, the job reads the environment variable TARGET and prints "Hello ${TARGET}!". If this environment variable is empty, "Hello World!" is returned. For more information about the code that is used for this example, see testjob.

1. Navigate to your job page.

   • From the Code Engine Projects page, click the name of your project. Click Jobs to work with your jobs and job runs.
   • From the Jobs page, click the Jobs tab, and click the name of the job that you want to update.

2. From the Configuration tab, update the image reference of your job. Provide the name of your image or configure an image. Update the name of the image from icr.io/codeengine/firstjob to icr.io/codeengine/testjob. Click Deploy.

3. Click Submit job.

4. From the Submit job pane, review and optionally change default configuration values such as instances, CPU, memory, number of job retries, and job timeout. You can specify either Array size or Array indices for the parallel job instances to run. For Array size, provide the number of instances to run in parallel for this job. For Array indices, provide a comma-separated list for your custom set of indices. For example, to run this job with a custom set of 5 indices, specify 3,12-14,25. Click Submit job again to run your job. The system displays the status of the instances of your job on the Job details page.

5. By viewing job logs from the console for this job, the output of the job is Hello World!.

6. To update the job again and add an environment variable, navigate to your job page.

7. From the Configuration > Environment variables tab, click Add environment variable. Add a literal environment variable with the name of TARGET with a value of Sunshine. The icr.io/codeengine/testjob outputs the message, Hello <value_of_TARGET>!>.

8. Click Add to add your environment variable and then click Save to save the changes to your job.

9. Click Submit job to submit the updated job.

10. From the Submit job pane, review and optionally change default configuration values such as instances, CPU, memory, number of job retries, and job timeout. This time, specify Array size as 3. Click Submit job again to run your job. The system displays the status of the instances of your job on the Job details page. From the Configuration section of the Job details page, the information about the number of instances is displayed as Array indices, which is 0 - 2 for this example.

11. By viewing job logs from the console for this job, the output of the updated job is Hello Sunshine!.

Next steps

• After you create your job, submit the job to run it. See Run a job. You can run your job multiple times.

• After you run your job, to view details of your job and job runs, see access job details.

• Now that your job is created, consider making your jobs event-driven. By using event subscriptions, you can trigger your jobs by periodic schedules or set your job to react to events like file uploads.

• You can update your job and its referenced code in any of the following ways, independent of how you created or previously updated your job.

  • If you have a container image, per the Open Container Initiative (OCI) standard, then you need to provide only a reference to the image, which points to the location of your container registry when you create (or update) your job. You can create (or update) your job from images in a public registry or private registry and then access the referenced image from your job run.

    If you created your job by using the job create command and you specified the --build-source option to build the container image from local or repository source, and you want to change your job to point to a different container image, you must first remove the association of the build from your job. For example, run ibmcloud ce job update -n JOB_NAME --build-clear. After you remove the association of the build from your job, you can update the job to reference a different image.

  • If you are starting with source code that resides in a Git repository, you can choose to let Code Engine take care of building the image from your source and creating (or updating) the job with a single operation. In this scenario, Code Engine uploads your image to IBM Cloud® Container Registry. To learn more, see Creating a job from repository source code. If you want more control over the build of your image, then you can choose to build the image with Code Engine before you create (or update) your job and run the job.

  • If you are starting with source code that resides on a local workstation, you can choose to let Code Engine take care of building the image from your source and creating the job with a single CLI command. In this scenario, Code Engine uploads your image to IBM Cloud® Container Registry. To learn more, see Creating your job from local source code with the CLI. If you want more control over the build of your image, then you can choose to build the image) with Code Engine before you create (or update) your job and run the job.

  For example, you might choose to let Code Engine handle the build of your local source while you evolve the development of your source for the job. Then, after the image is matured, you can update the job to reference the specific image that you want. You can repeat this process as needed.

  When you run your updated job, the latest version of your referenced container image is used for the job run, unless a tag is specified for the image. If a tag is specified for the image, then the tagged image is used for the job run.

Looking for more code examples? Check out the Samples for IBM Cloud Code Engine GitHub repo.