Part-46: Trigger a Cloud Function based on Pubsub Subscriptions in GCP

#googlecloud #serverless #devops #tutorial

☁️ Cloud Functions – Cloud Pub/Sub Trigger

Google Cloud Functions integrates seamlessly with Cloud Pub/Sub to execute code whenever a message is published to a topic. This allows for event-driven architectures where functions react to data streams in real time. 🚀

✅ Step-01: Introduction

We’ll create:

A Cloud Pub/Sub Topic
A Cloud Function triggered by Pub/Sub Events

✅ Step-02: Create Cloud Pub/Sub Topic

Navigate to Cloud Pub/Sub → CREATE TOPIC

Enter the following details:

Topic ID: mytopic1
Leave the rest of the settings as default

Click CREATE

Review your setup:

Check that the Topic was created
Verify the Subscription is attached

✅ Step-03: Create Cloud Function with Pub/Sub Trigger

Configuration Tab

Service name: cf-demo2-events-pubsub
Region: us-central1
Trigger: Cloud Pub/Sub
Topic: mytopic1
More Options → Review defaults
Click NEXT

Code Tab

Runtime: Node.js 20
Use the auto-populated sample code (below)
Click Save and DEPLOY

const functions = require('@google-cloud/functions-framework');

// Register a CloudEvent callback with the Functions Framework that will
// be executed when the Pub/Sub trigger topic receives a message.
functions.cloudEvent('helloPubSub', cloudEvent => {
  // The Pub/Sub message is passed as the CloudEvent's data payload.
  const base64name = cloudEvent.data.message.data;

  const name = base64name
    ? Buffer.from(base64name, 'base64').toString()
    : 'World';

  console.log(`Hello, ${name}!`);
});

✅ Step-04: Review Cloud Function Logs