Triggering a Cloud Function with Cloud Pub/Sub

1. Use the API Library to find and enable the Cloud Pub/Sub API.
2. Use the API Library to find and enable the Cloud Functions API.
3. Use the API Library to find and enable the Cloud Build API.

1. From the main console navigation, go to Cloud Pub/Sub (Now found under Analytics, Pub/Sub)
2. Click Create a topic.
3. In the dialog, enter a name greetings for the topic.
4. Click Create.

1. From the main console, go to Cloud Functions.
2. Click Create function.
3. Configure the function with the following values:
   • Name: acg-pubsub-function
   • Trigger: Cloud Pub/Sub
   • Topic: [Topic just created]
4. Click Save.
5. Make sure to expand out the "Runtime, build, connections and security settings" section, and set the "Maximum number of instances" to 1.
6. Click Next.
   • Runtime: Python 3.9
   • Source code: Inline editor
7. In the main.py field, enter the following code:

import base64

def greetings_pubsub(data, context):

    if 'data' in data:
        name = base64.b64decode(data['data']).decode('utf-8')
    else:
        name = 'folks'
    print('Greetings {} from Linux Academy!'.format(name))

6. Set Entry Point to greetings_pubsub.
7. Click Deploy.

1. Click the newly created Cloud Function name.
2. Switch to Trigger.
3. Click the topic link to go to the Cloud Pub/Sub topic.
4. From the Topic page, click Publish Message.
5. In the Message field, enter everyone around the world.
6. Click Publish.

1. Return to the Cloud Functions dashboard.
2. Click the Cloud Function's name.
3. From the Cloud Function navigation, click Logs.
4. Locate the most recent log.
5. Confirm function execution.

1. Open the Projects dialog and copy the current project ID.

2. Click Activate Cloud Shell from the top row of the console.

3. In the Cloud Shell, enter the following code: gcloud config set project [PROJECT_ID]

4. Next, enter the following code:

    DATA=$(printf 'my friends' | base64)
    gcloud functions call acg-pubsub-function --data '{"data":"'$DATA'"}'
   

5. After a moment, refresh the logs page and confirm the Cloud Function execution.

1. In the Cloud Shell, enter the following command:

    gcloud pubsub topics publish greetings --message "y'all"
   

2. After a moment, refresh the log page to confirm the function has executed.