Container Service for Kubernetes:Create a Job

ACK console

1. Log on to the ACK console. In the navigation pane on the left, click Clusters.

2. On the Clusters page, find the cluster you want and click its name. In the left-side pane, choose Workloads > Jobs.

3. On the Jobs page, click Create from Image in the upper-left corner.

4. In the Basic Information step, configure the basic settings of the application. Then, click Next to go to the Container step.

5. In the General section, enter registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest in the Image Name field. In the Start part of the Lifecycle section, enter /bin/sh in the Command field and enter ["-c", "echo 'starting...'; COUNTER=0; while [ $COUNTER -lt 5 ]; do sleep 2; COUNTER=$((COUNTER+1)); echo $COUNTER; done; echo 'finished'; exit 0"] in the Parameter field, as shown in the following figure. Then, click Next to go to the Advanced step.

   Important

   Before pulling the registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest image, you need to enable Internet access for the cluster. If you keep the default value for the Configure SNAT for VPC parameter when you create a cluster, the cluster can access the Internet. For more information about how to enable Internet access for an existing cluster, see Enable an existing ACK cluster to access the Internet.

   

6. In the Advanced step, configure the Completions and Parallelism parameters. In this example, Completions is set to 2. For more information about the preceding parameters, see Introduction to Jobs. Then, click Create in the lower part of the page.

   

   Section	Parameter	Description
   Job Settings	Completions	The number of pods that must terminate with success. This parameter corresponds to the spec.completions parameter of the Job configurations.
   	Parallelism	The number of pods that can run in parallel. This parameter corresponds to the spec.parallelism parameter of the Job configurations.
   	Timeout	The timeout period of the Job execution. This parameter corresponds to the spec.activeDeadlineSeconds parameter of the Job configurations. If the Job execution times out, the Job is terminated, regardless of whether the number of pods that terminate with success reaches the specified value. This parameter is suitable for tasks that are strictly time-sensitive or may encounter infinite loop execution. Default value: 600. Unit: seconds.
   	BackoffLimit	The maximum number of retries that are performed by the Job upon pod failures. This parameter corresponds to the spec.backoffLimit parameter of the Job configurations. Default value: 6.
   	Restart	The pod restart policy. This parameter corresponds to the template.spec.restartPolicy parameter of the Job configurations. Valid values: Never: When a container in a pod exceptionally exits, the system tries to restart the pod. In this case, the system does not create a new pod. The restart does not count toward the retry limit specified by the spec.backoffLimit parameter. On Failure: When a pod fails, the system creates a new one to replace the failed pod.
   Labels, Annotations	Pod Labels	Add a label to each pod to which the workload belongs. All resources in the cluster, including workloads and services, are matched with pods by using labels. By default, ACK adds labels in the format of app:(application name) to pods.
   	Pod Annotations	Add an annotation to each pod to which the workload belongs. Some features in ACK use annotations. You can configure the annotations when you use these features.

7. After you create the Job, you can view the logs of the Job in the ACK console. The logs show that the two pods created by the Job return the same output.

   

kubectl

1. Create a file named job.yaml and copy the following YAML template to the file:

   apiVersion: batch/v1 kind: Job metadata: name: example-job spec: completions: 2 # Stop the Job after two pods terminate with success. parallelism: 1 # Run only one pod at a time. template: spec: containers: - name: counter image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest command: - /bin/sh - -c - | echo "starting..."; COUNTER=0; while [ $COUNTER -lt 5 ]; do sleep 2; COUNTER=$((COUNTER+1)); echo "${COUNTER}"; done; echo "finished"; exit 0 restartPolicy: Never # Use the Never pod restart policy.

2. Run the following command to create the Job:

   kubectl apply -f job.yaml

   Expected output:

   job.batch/example-job created

3. After the Job is created, wait 15 seconds and run the following command to query the Job status:

   kubectl get job example-job

   The following output shows that one pod has terminated with success and the Job is in the Running state.

   NAME STATUS COMPLETIONS DURATION AGE example-job Running 1/2 16s 16s

4. After the Job is created, wait 40 seconds and run the following command to query the Job status:

   kubectl get job example-job

   The following output shows that the Job is complete.

   NAME STATUS COMPLETIONS DURATION AGE example-job Complete 2/2 27s 37s

5. Run the following command to query the logs of the Job:

   kubectl logs -l job-name=example-job

   Expected output:

   starting... 1 2 3 4 5 finished starting... 1 2 3 4 5 finished