Schedule and run a cron job using the Google Cloud console

Create a Pub/Sub topic and subscription

A Pub/Sub topic is a resource to which publishers can send messages. To receive messages published to a topic, you must create a subscription to that topic.

1. In the Google Cloud console, go to the Pub/Sub page.

   Go to Pub/Sub

2. Click Create topic.

3. In the Topic ID field, enter cron-topic as the ID for your topic.

4. Retain the defaults including the Add a default subscription option.

5. Don't select any other options.

6. Click Create.

This creates a Pub/Sub topic called cron-topic and a subscription for that topic called cron-topic-sub.

Create a cron job using Cloud Scheduler

Set up a scheduled unit of work known as a cron job that is sent to a target on a recurring schedule.

1. In the Google Cloud console, go to the Cloud Scheduler page.

   Go to Cloud Scheduler

2. Click Create job.

3. Give your job a name.

4. In the Region list, select a region for your job.

5. Specify a Frequency for your job, using a format based on unix-cron. For example:

   30 16 * * 7
   

   For more information, see Configure cron job schedules.

6. In the Timezone list, select a time zone.

   For some time zones, daylight savings time can cause jobs to run or not run unexpectedly. For more information, see Time zone.

7. Click Continue.

8. In the Target type list, select Pub/Sub.

9. Select the topic you created earlier: cron-topic.

10. In the Message body field, enter a string to be sent to your Pub/Sub target topic. For example: "Hello world!"

11. Click Create.

You've created a job that sends a message to a Pub/Sub topic at 16:30 on Sundays. You can now run the job.

Run your job

In addition to executing according to its specified schedule, you can force your job to run immediately.

1. In the Google Cloud console, go to the Cloud Scheduler page.

   Go to Cloud Scheduler

   Your job should be listed.

2. In the row for your job, click more_vert Actions > Force run.

   Note that due to some initial configuration, the first job created in a project can take a few minutes to run.

3. In the Status of last execution column, a Success status indicates that you have successfully run your cron job.

Next, you can verify that Pub/Sub received the message.

Verify the results in Pub/Sub

Verify that your Pub/Sub topic is receiving messages from your job by pulling Pub/Sub messages from the subscription.

1. In the Google Cloud console, go to the Pub/Sub subscriptions page.

   Go to Pub/Sub

2. Click the subscription for your Pub/Sub topic.

3. Click the Messages tab.

4. Click Pull.

You should see the message that you published, with the message body, Hello world, and the time when the message was published.