multicast-eventer

An EventEmitter for publishing & subscribing to multicast events across a network.

Installation

$ npm install multicast-eventer

Setup

If you're setting up your device for the first time and running Linux, there is a handy setupRoutes function included in the package to set up the multicast routes.

setup.js

const { setupRoutes } = require('multicast-eventer');

// add multicast route to usual network interfaces
setupRoutes();

Or if you know what network interface you'll be using, i.e eth0 for ethernet or wlan0 for WiFI, you can pass that as an argument to setupRoutes.

setup.js

const { setupRoutes } = require('multicast-eventer');

// add multicast route to usual network interfaces
setupRoutes('wlan0');

Usage

You can use this package just like any other EventEmitter, expect the events will span devices instead of the local program:

device-one.js

const { MulticastEmitter } = require('multicast-eventer');
const emitter = new MulticastEmitter();

emitter.on('test', data => console.log(`Message from ${data.device}: `, data));
emitter.on('error', console.error);

device-two.js

const { MulticastEmitter } = require('multicast-eventer');
const emitter = new MulticastEmitter();

// the 2nd argument could be an object with anything you want
emitter.emit('test', { message: 'This could be anything' })

Options

• address (String): the multicast IPv4 address to listen on (valid from 224.0.0.1 to 239.255.255.254). Default is 239.10.10.100.
• broadcast (Boolean): When set to true, UDP packets may be sent to a local interface's broadcast address. Default is true.
• loopback (Boolean): When set to true, multicast packets will also be received on the local interface. Default is false.
• name (String): Name of the device to emit with events. Default is the hostname for the device.
• port (Number): Destination port. Default is 33333.
• ttl (Number): Specifies the number of IP hops that a packet is allowed to travel through, specifically for multicast traffic. Default is 128.

Test

For now, the test is basically ensuring the TypeScript source compiles successfully.

$ npm test