Create and run a job that sends Pub/Sub status notifications

This document explains how to create a Batch job that sends Pub/Sub notifications. You can use Pub/Sub to get notifications when a job or task state changes, or when a job or task enters a specific state. For more information, see Monitor jobs using notifications.

Before you begin

  1. If you haven't used Batch before, review Get started with Batch and enable Batch by completing the prerequisites for projects and users.
  2. Create or identify a Pub/Sub topic for Batch notifications.
  3. Configure a subscription to receive and use the notifications.

Required roles

  • To get the permissions that you need to create and run a job that sends notifications, ask your administrator to grant you the following IAM roles:

    For more information about granting roles, see Manage access to projects, folders, and organizations.

    You might also be able to get the required permissions through custom roles or other predefined roles.

  • Unless you are using the default configuration for the job's service account, ensure that it has the necessary permissions.

    To ensure that the job's service account has the necessary permissions to publish Pub/Sub notifications, ask your administrator to grant the job's service account the Pub/Sub Publisher (roles/pubsub.publisher) IAM role on your Pub/Sub topic.

  • If you want a job to publish notifications to a Pub/Sub topic that is in a different project than the job, then the Batch service agent for the job's project must be granted permission to publish to that topic.

    To ensure that the Batch service agent for the job's project has the necessary permissions to publish Pub/Sub notifications to a Pub/Sub topic in another project, ask your administrator to grant the Batch service agent for the job's project the Pub/Sub Publisher (roles/pubsub.publisher) IAM role on the Pub/Sub topic.

Create and run a job that sends notifications

You can create a Batch job that sends Pub/Sub notifications by doing the following:

gcloud

Use the Google Cloud CLI to create a job that includes the notifications field and one or more jobNotification objects in the main body of the JSON file:

{
...
  "notifications": [
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        ATTRIBUTES
      }
    }
  ]
...
}

Replace the following:

  • PROJECT_ID: the project ID of the project that contains the Pub/Sub topic.
  • TOPIC_ID: the Pub/Sub topic ID of the topic you created when you enabled Pub/Sub notifications.

  • ATTRIBUTES: specify one or more of the following attributes, which each let you receive notifications about the state of the job or all of its tasks.

    • For notifications about all job state changes, specify the following:

      "type": "JOB_STATE_CHANGED"

    • For notifications about a specific job state change, specify the following:

      "type": "JOB_STATE_CHANGED",
"newJobState": "JOB_STATE"

      Replace JOB_STATE with one of the following job states:

      • QUEUED
      • SCHEDULED
      • RUNNING
      • SUCCEEDED
      • FAILED

      For more information about job states, see Job lifecycle.

    • For notifications about all task state changes, specify the following:

      "type": "TASK_STATE_CHANGED"

    • For notifications about specific task state changes, specify the following:

      "type": "TASK_STATE_CHANGED",
"newTaskState": "TASK_STATE"

      Replace TASK_STATE with one of the following task states:

      • PENDING
      • ASSIGNED
      • RUNNING
      • SUCCEEDED
      • FAILED

      For more information about task states, see Job lifecycle.

For example, suppose you want to receive notifications about all job state changes and any time a task fails. To do so, you can have a JSON configuration file that is similar to the following:

{
  "taskGroups": [
    {
      "taskSpec": {
        "runnables": [
          {
            "script": {
              "text": "echo Hello World! This is task $BATCH_TASK_INDEX."
            }
          }
        ]
      },
      "taskCount": 3,
    }
  ],
  "logsPolicy": {
      "destination": "CLOUD_LOGGING"
  },
  "notifications": [
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        "type": "JOB_STATE_CHANGED"
      }
    },
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        "type": "TASK_STATE_CHANGED",
        "newTaskState": "FAILED"
      }
    }
  ]
}

API

Use the REST API to create a job that includes the notifications field and one or more jobNotification objects in the main body of the JSON file:

{
...
  "notifications": [
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        ATTRIBUTES
      }
    }
  ]
...
}

Replace the following:

  • PROJECT_ID: the project ID of the project that contains the Pub/Sub topic.
  • TOPIC_ID: the Pub/Sub topic ID of the topic you created when you enabled Pub/Sub notifications.

  • ATTRIBUTES: specify one or more of the following attributes, which each let you receive notifications about the state of the job or all of its tasks.

    • For notifications about all job state changes, specify the following:

      "type": "JOB_STATE_CHANGED"

    • For notifications about a specific job state change, specify the following:

      "type": "JOB_STATE_CHANGED",
"newJobState": "JOB_STATE"

      Replace JOB_STATE with one of the following job states:

      • QUEUED
      • SCHEDULED
      • RUNNING
      • SUCCEEDED
      • FAILED

      For more information about job states, see Job lifecycle.

    • For notifications about all task state changes, specify the following:

      "type": "TASK_STATE_CHANGED"

    • For notifications about specific task state changes, specify the following:

      "type": "TASK_STATE_CHANGED",
"newTaskState": "TASK_STATE"

      Replace TASK_STATE with one of the following task states:

      • PENDING
      • ASSIGNED
      • RUNNING
      • SUCCEEDED
      • FAILED

      For more information about task states, see Job lifecycle.

For example, suppose you want to receive notifications about all job state changes and any time a task fails. To do so, you can have a JSON configuration file that is similar to the following:

{
  "taskGroups": [
    {
      "taskSpec": {
        "runnables": [
          {
            "script": {
              "text": "echo Hello World! This is task $BATCH_TASK_INDEX."
            }
          }
        ]
      },
      "taskCount": 3,
    }
  ],
  "logsPolicy": {
      "destination": "CLOUD_LOGGING"
  },
  "notifications": [
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        "type": "JOB_STATE_CHANGED"
      }
    },
    {
      "pubsubTopic": "projects/PROJECT_ID/topics/TOPIC_ID",
      "message": {
        "type": "TASK_STATE_CHANGED",
        "newTaskState": "FAILED"
      }
    }
  ]
}

Go 

import (
	"context"
	"fmt"
	"io"

	batch "cloud.google.com/go/batch/apiv1"
	"cloud.google.com/go/batch/apiv1/batchpb"
	durationpb "google.golang.org/protobuf/types/known/durationpb"
)

// Creates and runs a job with configured notifications
func createJobWithNotifications(w io.Writer, projectID, region, jobName, topicName string) (*batchpb.Job, error) {

	ctx := context.Background()
	batchClient, err := batch.NewClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("batchClient error: %w", err)
	}
	defer batchClient.Close()

	script := &batchpb.Runnable_Script_{
		Script: &batchpb.Runnable_Script{
			Command: &batchpb.Runnable_Script_Text{
				Text: "echo Hello world! This is task ${BATCH_TASK_INDEX}. This job has a total of ${BATCH_TASK_COUNT} tasks.",
			},
		},
	}

	taskSpec := &batchpb.TaskSpec{
		ComputeResource: &batchpb.ComputeResource{
			// CpuMilli is milliseconds per cpu-second. This means the task requires 2 whole CPUs.
			CpuMilli:  2000,
			MemoryMib: 16,
		},
		MaxRunDuration: &durationpb.Duration{
			Seconds: 3600,
		},
		MaxRetryCount: 2,
		Runnables: []*batchpb.Runnable{{
			Executable: script,
		}},
	}

	taskGroups := []*batchpb.TaskGroup{
		{
			TaskCount: 4,
			TaskSpec:  taskSpec,
		},
	}

	labels := map[string]string{"env": "testing", "type": "container"}

	// Policies are used to define on what kind of virtual machines the tasks will run on.
	// In this case, we tell the system to use "e2-standard-4" machine type.
	// Read more about machine types here: https://cloud.google.com/compute/docs/machine-types
	allocationPolicy := &batchpb.AllocationPolicy{
		Instances: []*batchpb.AllocationPolicy_InstancePolicyOrTemplate{{
			PolicyTemplate: &batchpb.AllocationPolicy_InstancePolicyOrTemplate_Policy{
				Policy: &batchpb.AllocationPolicy_InstancePolicy{
					MachineType: "e2-standard-4",
				},
			},
		}},
	}

	// We use Cloud Logging as it's an out of the box available option
	logsPolicy := &batchpb.LogsPolicy{
		Destination: batchpb.LogsPolicy_CLOUD_LOGGING,
	}

	notifications := []*batchpb.JobNotification{
		{
			PubsubTopic: fmt.Sprintf("projects/%s/topics/%s", projectID, topicName),
			Message: &batchpb.JobNotification_Message{
				Type: batchpb.JobNotification_JOB_STATE_CHANGED,
			},
		},
		{
			PubsubTopic: fmt.Sprintf("projects/%s/topics/%s", projectID, topicName),
			Message: &batchpb.JobNotification_Message{
				Type:         batchpb.JobNotification_TASK_STATE_CHANGED,
				NewTaskState: batchpb.TaskStatus_FAILED,
			},
		},
	}

	job := &batchpb.Job{
		Name:             jobName,
		TaskGroups:       taskGroups,
		AllocationPolicy: allocationPolicy,
		Labels:           labels,
		Notifications:    notifications,
		LogsPolicy:       logsPolicy,
	}

	request := &batchpb.CreateJobRequest{
		Parent: fmt.Sprintf("projects/%s/locations/%s", projectID, region),
		JobId:  jobName,
		Job:    job,
	}

	created_job, err := batchClient.CreateJob(ctx, request)
	if err != nil {
		return nil, fmt.Errorf("unable to create job: %w", err)
	}

	fmt.Fprintf(w, "Job created: %v\n", created_job)
	return created_job, nil
}

Java 


import com.google.cloud.batch.v1.BatchServiceClient;
import com.google.cloud.batch.v1.CreateJobRequest;
import com.google.cloud.batch.v1.Job;
import com.google.cloud.batch.v1.JobNotification;
import com.google.cloud.batch.v1.JobNotification.Message;
import com.google.cloud.batch.v1.JobNotification.Type;
import com.google.cloud.batch.v1.LogsPolicy;
import com.google.cloud.batch.v1.LogsPolicy.Destination;
import com.google.cloud.batch.v1.Runnable;
import com.google.cloud.batch.v1.Runnable.Script;
import com.google.cloud.batch.v1.TaskGroup;
import com.google.cloud.batch.v1.TaskSpec;
import com.google.cloud.batch.v1.TaskStatus.State;
import com.google.common.collect.Lists;
import com.google.protobuf.Duration;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class CreateBatchNotification {

  public static void main(String[] args)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // TODO(developer): Replace these variables before running the sample.
    // Project ID or project number of the Google Cloud project you want to use.
    String projectId = "YOUR_PROJECT_ID";
    // Name of the region you want to use to run the job. Regions that are
    // available for Batch are listed on: https://cloud.google.com/batch/docs/get-started#locations
    String region = "europe-central2";
    // The name of the job that will be created.
    // It needs to be unique for each project and region pair.
    String jobName = "JOB_NAME";
    // The Pub/Sub topic ID to send the notifications to.
    String topicId = "TOPIC_ID";

    createBatchNotification(projectId, region, jobName, topicId);
  }

  // Create a Batch job that sends notifications to Pub/Sub
  public static Job createBatchNotification(String projectId, String region, String jobName,
                                            String topicId)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests.
    try (BatchServiceClient batchServiceClient = BatchServiceClient.create()) {
      // Define what will be done as part of the job.
      Runnable runnable =
          Runnable.newBuilder()
              .setScript(
                  Script.newBuilder()
                      .setText(
                          "echo Hello world! This is task ${BATCH_TASK_INDEX}. "
                                  + "This job has a total of ${BATCH_TASK_COUNT} tasks.")
                      // You can also run a script from a file. Just remember, that needs to be a
                      // script that's already on the VM that will be running the job.
                      // Using setText() and setPath() is mutually exclusive.
                      // .setPath("/tmp/test.sh")
                      .build())
              .build();

      TaskSpec task = TaskSpec.newBuilder()
              // Jobs can be divided into tasks. In this case, we have only one task.
              .addRunnables(runnable)
              .setMaxRetryCount(2)
              .setMaxRunDuration(Duration.newBuilder().setSeconds(3600).build())
              .build();

      // Tasks are grouped inside a job using TaskGroups.
      // Currently, it's possible to have only one task group.
      TaskGroup taskGroup = TaskGroup.newBuilder()
          .setTaskCount(3)
          .setParallelism(1)
          .setTaskSpec(task)
          .build();

      Job job =
          Job.newBuilder()
              .addTaskGroups(taskGroup)
              .addAllNotifications(buildNotifications(projectId, topicId))
              .putLabels("env", "testing")
              .putLabels("type", "script")
              // We use Cloud Logging as it's an out of the box available option.
              .setLogsPolicy(
                  LogsPolicy.newBuilder().setDestination(Destination.CLOUD_LOGGING))
              .build();

      CreateJobRequest createJobRequest =
          CreateJobRequest.newBuilder()
              // The job's parent is the region in which the job will run.
              .setParent(String.format("projects/%s/locations/%s", projectId, region))
              .setJob(job)
              .setJobId(jobName)
              .build();

      Job result =
          batchServiceClient
              .createJobCallable()
              .futureCall(createJobRequest)
              .get(5, TimeUnit.MINUTES);

      System.out.printf("Successfully created the job: %s", result.getName());

      return result;
    }
  }

  // Creates notification configurations to send messages to Pub/Sub when the state is changed
  private static Iterable<JobNotification> buildNotifications(String projectId, String topicId) {
    String pubsubTopic = String.format("projects/%s/topics/%s", projectId, topicId);

    JobNotification jobStateChanged = JobNotification.newBuilder()
            .setPubsubTopic(pubsubTopic)
            .setMessage(Message.newBuilder().setType(Type.JOB_STATE_CHANGED))
            .build();

    JobNotification taskStateChanged = JobNotification.newBuilder()
            .setPubsubTopic(pubsubTopic)
            .setMessage(Message.newBuilder()
                    .setType(Type.TASK_STATE_CHANGED)
                    .setNewTaskState(State.FAILED))
            .build();

    return Lists.newArrayList(jobStateChanged, taskStateChanged);
  }
}

Node.js 

// Imports the Batch library
const batchLib = require('@google-cloud/batch');
const batch = batchLib.protos.google.cloud.batch.v1;

// Instantiates a client
const batchClient = new batchLib.v1.BatchServiceClient();

/**
 * TODO(developer): Update these variables before running the sample.
 */
// Project ID or project number of the Google Cloud project you want to use.
const PROJECT_ID = await batchClient.getProjectId();
// Name of the region you want to use to run the job. Regions that are
// available for Batch are listed on: https://cloud.google.com/batch/docs/get-started#locations
const REGION = 'europe-central2';
// The name of the job that will be created.
// It needs to be unique for each project and region pair.
const JOB_NAME = 'job-name-batch-notifications';
// The Pub/Sub topic ID to send the notifications to.
const TOPIC_ID = 'topic-id';

// Define what will be done as part of the job.
const task = new batch.TaskSpec();
const runnable = new batch.Runnable();
runnable.script = new batch.Runnable.Script();
runnable.script.commands = [
  '-c',
  'echo Hello world! This is task ${BATCH_TASK_INDEX}.',
];
task.runnables = [runnable];
task.maxRetryCount = 2;
task.maxRunDuration = {seconds: 3600};

// Tasks are grouped inside a job using TaskGroups.
const group = new batch.TaskGroup();
group.taskCount = 3;
group.taskSpec = task;

// Create batch notification when job state changed
const notification1 = new batch.JobNotification();
notification1.pubsubTopic = `projects/${PROJECT_ID}/topics/${TOPIC_ID}`;
notification1.message = {
  type: 'JOB_STATE_CHANGED',
};

// Create batch notification when task state changed
const notification2 = new batch.JobNotification();
notification2.pubsubTopic = `projects/${PROJECT_ID}/topics/${TOPIC_ID}`;
notification2.message = {
  type: 'TASK_STATE_CHANGED',
  newTaskState: 'FAILED',
};

const job = new batch.Job();
job.name = JOB_NAME;
job.taskGroups = [group];
job.notifications = [notification1, notification2];
job.labels = {env: 'testing', type: 'script'};
// We use Cloud Logging as it's an option available out of the box
job.logsPolicy = new batch.LogsPolicy();
job.logsPolicy.destination = batch.LogsPolicy.Destination.CLOUD_LOGGING;
// The job's parent is the project and region in which the job will run
const parent = `projects/${PROJECT_ID}/locations/${REGION}`;

async function callCreateBatchNotifications() {
  // Construct request
  const request = {
    parent,
    jobId: JOB_NAME,
    job,
  };

  // Run request
  const [response] = await batchClient.createJob(request);
  console.log(JSON.stringify(response));
}

await callCreateBatchNotifications();

Python 

from google.cloud import batch_v1


def create_with_pubsub_notification_job(
    project_id: str, region: str, job_name: str, topic_name: str
) -> batch_v1.Job:
    """
    This method shows how to create a sample Batch Job that will run
    a simple command inside a container on Cloud Compute instances.

    Args:
        project_id: project ID or project number of the Cloud project you want to use.
        region: name of the region you want to use to run the job. Regions that are
            available for Batch are listed on: https://cloud.google.com/batch/docs/locations
        job_name: the name of the job that will be created.
            It needs to be unique for each project and region pair.
        topic_name: the name of the Pub/Sub topic to which the notification will be sent.
            The topic should be created in GCP Pub/Sub before running this method.
            The procedure for creating a topic is listed here: https://cloud.google.com/pubsub/docs/create-topic

    Returns:
        A job object representing the job created.
    """

    client = batch_v1.BatchServiceClient()

    # Define what will be done as part of the job.
    runnable = batch_v1.Runnable()
    runnable.container = batch_v1.Runnable.Container()
    runnable.container.image_uri = "gcr.io/google-containers/busybox"
    runnable.container.entrypoint = "/bin/sh"
    runnable.container.commands = [
        "-c",
        "echo Hello world! This is task ${BATCH_TASK_INDEX}. This job has a total of ${BATCH_TASK_COUNT} tasks.",
    ]

    # Jobs can be divided into tasks. In this case, we have only one task.
    task = batch_v1.TaskSpec()
    task.runnables = [runnable]

    # We can specify what resources are requested by each task.
    resources = batch_v1.ComputeResource()
    resources.cpu_milli = 2000  # in milliseconds per cpu-second. This means the task requires 2 whole CPUs.
    resources.memory_mib = 16  # in MiB
    task.compute_resource = resources

    task.max_retry_count = 2
    task.max_run_duration = "3600s"

    # Tasks are grouped inside a job using TaskGroups.
    # Currently, it's possible to have only one task group.
    group = batch_v1.TaskGroup()
    group.task_count = 4
    group.task_spec = task

    # Policies are used to define on what kind of virtual machines the tasks will run on.
    # In this case, we tell the system to use "e2-standard-4" machine type.
    # Read more about machine types here: https://cloud.google.com/compute/docs/machine-types
    policy = batch_v1.AllocationPolicy.InstancePolicy()
    policy.machine_type = "e2-standard-4"
    instances = batch_v1.AllocationPolicy.InstancePolicyOrTemplate()
    instances.policy = policy
    allocation_policy = batch_v1.AllocationPolicy()
    allocation_policy.instances = [instances]

    job = batch_v1.Job()
    job.task_groups = [group]
    job.allocation_policy = allocation_policy
    job.labels = {"env": "testing", "type": "container"}
    # We use Cloud Logging as it's an out of the box available option
    job.logs_policy = batch_v1.LogsPolicy()
    job.logs_policy.destination = batch_v1.LogsPolicy.Destination.CLOUD_LOGGING

    # Configuring the first notification
    notification1 = batch_v1.JobNotification()
    notification1.pubsub_topic = f"projects/{project_id}/topics/{topic_name}"
    # Define the message that will be sent to the topic
    first_massage = batch_v1.JobNotification.Message()
    # Specify the new job state that will trigger the notification
    # In this case, the notification is triggered when the job state changes to SUCCEEDED
    first_massage.type_ = batch_v1.JobNotification.Type.JOB_STATE_CHANGED
    first_massage.new_job_state = batch_v1.JobStatus.State.SUCCEEDED
    # Assign the message to the notification
    notification1.message = first_massage

    # Configuring the second notification
    notification2 = batch_v1.JobNotification()
    notification2.pubsub_topic = f"projects/{project_id}/topics/{topic_name}"
    second_message = batch_v1.JobNotification.Message()
    second_message.type_ = batch_v1.JobNotification.Type.TASK_STATE_CHANGED
    second_message.new_task_state = batch_v1.TaskStatus.State.FAILED
    notification2.message = second_message

    # Assign a list of notifications to the job.
    job.notifications = [notification1, notification2]

    create_request = batch_v1.CreateJobRequest()
    create_request.job = job
    create_request.job_id = job_name
    # The job's parent is the region in which the job will run
    create_request.parent = f"projects/{project_id}/locations/{region}"
    return client.create_job(create_request)

After the job starts running, you can use its notifications. For example, if the Pub/Sub topic for your job has a subscription that streams notifications to BigQuery, you can analyze the Pub/Sub notifications in BigQuery.

What's next