Socket.IO Google Cloud pub/sub adapter

The @socket.io/gcp-pubsub-adapter package allows broadcasting packets between multiple Socket.IO servers.

Table of contents

• Supported features
• Installation
• Usage
• Options
• License

Supported features

Feature	socket.io version	Support
Socket management	4.0.0	✅ YES (since version 0.1.0)
Inter-server communication	4.1.0	✅ YES (since version 0.1.0)
Broadcast with acknowledgements	4.5.0	✅ YES (since version 0.1.0)
Connection state recovery	4.6.0	❌ NO

Installation

npm install @socket.io/gcp-pubsub-adapter

Usage

import { PubSub } from "@google-cloud/pubsub";
import { Server } from "socket.io";
import { createAdapter } from "@socket.io/gcp-pubsub-adapter";

const pubsub = new PubSub({
  projectId: "your-project-id"
});

const topic = pubsub.topic(topicNameOrId);

const io = new Server({
  adapter: createAdapter(topic)
});

try {
  // wait for the creation of the pub/sub subscription
  await io.of("/").adapter.init();
} catch (err) {
  console.error(err);
  process.exitCode = 1;
}

const gracefulShutdown = async () => {
  try {
    // wait for the deletion of the pub/sub subscription
    await io.close();
  } catch (err) {
    console.error(err);
    process.exitCode = 1;
  }
};

process.once("SIGINT", gracefulShutdown);
process.once("SIGTERM", gracefulShutdown);

io.listen(3000);

Options

Name	Description	Default value
subscriptionPrefix	The prefix for the new subscription to create.	socket.io
subscriptionOptions	The options used to create the subscription.	-
heartbeatInterval	The number of ms between two heartbeats.	5_000
heartbeatTimeout	The number of ms without heartbeat before we consider a node down.	10_000

License

MIT