@google-cloud/pubsub

What is @google-cloud/pubsub?

The @google-cloud/pubsub npm package is a client library for accessing Google Cloud Pub/Sub, a fully-managed real-time messaging service that allows you to send and receive messages between independent applications. This package provides an easy-to-use API to interact with Google Cloud Pub/Sub and is designed to handle the complexities of the underlying API operations.

What are @google-cloud/pubsub's main functionalities?

Publishing Messages

This feature allows you to publish messages to a topic. The code sample demonstrates how to create a PubSub client, get a reference to a topic, and publish a message to that topic.

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();
const topic = pubsub.topic('my-topic');
const messageBuffer = Buffer.from('Hello, world!');
topic.publish(messageBuffer);

Subscribing to Topics

This feature enables you to subscribe to a topic and receive messages. The code sample shows how to create a PubSub client, get a reference to a subscription, and set up an event handler to process received messages.

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();
const subscription = pubsub.subscription('my-subscription');
subscription.on('message', message => {
  console.log('Received message:', message.data.toString());
  message.ack();
});

Managing Topics and Subscriptions

This feature covers the management of topics and subscriptions, including creating and deleting them. The code sample illustrates how to create a new topic and delete an existing subscription.

const {PubSub} = require('@google-cloud/pubsub');
const pubsub = new PubSub();
// Create a new topic
pubsub.createTopic('new-topic').then(response => {
  console.log('Topic created:', response[0].name);
});
// Delete a subscription
pubsub.subscription('old-subscription').delete();

Other packages similar to @google-cloud/pubsub

aws-sdk

The AWS SDK for JavaScript provides a similar messaging service through Amazon SNS (Simple Notification Service) and SQS (Simple Queue Service). While AWS SDK supports both pub/sub and queue-based messaging, @google-cloud/pubsub is specifically optimized for Google Cloud's Pub/Sub service.

azure-sb

Azure-sb is a client library for Azure Service Bus, which also supports pub/sub messaging patterns. Compared to @google-cloud/pubsub, azure-sb is tailored for integration with Azure's ecosystem and supports additional features like message sessions and dead-letter queues.

rascal

Rascal is an abstraction layer over amqplib for RabbitMQ, a popular open-source message broker. Unlike @google-cloud/pubsub, which is a cloud-native service, Rascal with RabbitMQ can be used both on-premises and in the cloud, offering more flexibility in deployment models.

README

Google Cloud Pub/Sub: Node.js Client

Cloud Pub/Sub is a fully-managed real-time messaging service that allows you to send and receive messages between independent applications.

This document contains to an API reference, samples, and other resources useful to developing Node.js applications. For additional help developing Pub/Sub applications, in Node.js and other languages, see our Pub/Sub quickstart, publisher, and subscriber guides.

• Google Cloud Pub/Sub Node.js Client API Reference
• Google Cloud Pub/Sub Documentation
• github.com/googleapis/nodejs-pubsub

Read more about the client libraries for Cloud APIs, including the older Google APIs Client Libraries, in Client Libraries Explained.

Table of contents:

• Quickstart
  • Before you begin
  • Installing the client library
  • Using the client library
• Samples
• Versioning
• Contributing
• License

Quickstart

Before you begin

1. Select or create a Cloud Platform project.
2. Enable billing for your project.
3. Enable the Google Cloud Pub/Sub API.
4. Set up authentication with a service account so you can access the API from your local workstation.

Installing the client library

npm install @google-cloud/pubsub

Using the client library

// Imports the Google Cloud client library
const {PubSub} = require('@google-cloud/pubsub');

async function quickstart(
  projectId = 'your-project-id', // Your Google Cloud Platform project ID
  topicName = 'my-topic' // Name for the new topic to create
) {
  // Instantiates a client
  const pubsub = new PubSub({projectId});

  // Creates the new topic
  const [topic] = await pubsub.createTopic(topicName);
  console.log(`Topic ${topic.name} created.`);
}

Running gRPC C++ bindings

For some workflows and environments it might make sense to use the C++ gRPC implementation, instead of the default one (see: #770):

To configure @google-cloud/pubsub to use an alternative grpc transport:

1. npm install grpc, adding grpc as a dependency.

2. instantiate @google-cloud/pubsub with grpc:

   const {PubSub} = require('@google-cloud/pubsub');
   const grpc = require('grpc');
   const pubsub = new PubSub({grpc});
   

Samples

Samples are in the samples/ directory. The samples' README.md has instructions for running the samples.

Sample	Source Code	Try it
Quickstart	source code
Subscriptions	source code
Topics	source code

The Google Cloud Pub/Sub Node.js Client API Reference documentation also contains samples.

Versioning

This library follows Semantic Versioning.

This library is considered to be General Availability (GA). This means it is stable; the code surface will not change in backwards-incompatible ways unless absolutely necessary (e.g. because of critical security issues) or with an extensive deprecation period. Issues and requests against GA libraries are addressed with the highest priority.

More Information: Google Cloud Platform Launch Stages

Contributing

Contributions welcome! See the Contributing Guide.

License

Apache Version 2.0

See LICENSE

Changelog

1.2.0 (2019-12-13)

Features

• ordered messaging (#716) (b2f96ff)