Basic MQTT Broker and Client Implementation

This project is a Proof of Concept of a basic MQTT broker and client implementation in NodeJS/Typescript. MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol commonly used in IoT (Internet of Things) applications.

I am using Aedes as a messaging broker and MQTT.js as client.

• Basic MQTT Broker and Client Implementation
  • Features
  • Example Usage
  • How to Use
    • Broker
      • create options object
      • create and start broker
    • Client
      • create options object
      • create client and connect
      • subscribe to a topic
      • publish a message
    • Examples
  • API
  • TLS

Features

This implementation supports:

• all in one solution
• insecure connections
• username/password authentication
• TLS connections
• Log Level Based Logging
• customizable event handlers
• client can act as both, subscriber and publisher

Install Package

npm i --save @m-reiniger/node-mqtt

Example Usage Standalone

Install Dependencies:

npm install

Build:

npm run build

Run Broker:

npm run broker

Rum Subscriber Client:

npm run subscriber

Run Publisher Client:

npm run publisher

How to Use

Broker

create options object

const options = {
    port: 8883,
    auth: {
        useAuth: true,
        username: 'user',
        password: 'pass'
    },
    tls: {
        useTLS: true,
        key: '--- your key file contents here ---',
        cert: '--- your cert file contents here ---'
    }
}

create and start broker

import { MQTTBroker } from "@m-reiniger/node-mqtt";

// create broker
const broker = new MQTTBroker(options);
// start broker server
broker.start();

Client

create options object

const options = {
    port: 8883,
    host: 'localhost'
    auth: {
        useAuth: true,
        username: 'user',
        password: 'pass'
    },
    tls: {
        useTLS: true,
        key: '--- your key file contents here ---',
        cert: '--- your cert file contents here ---'
    }
}

create client and connect

import { MQTTClient } from "@m-reiniger/node-mqtt";

// create client
const client = new MQTTClient(options);
// connect to broker
client.connect();

subscribe to a topic

client.subscribe('my/topic', (topic: string, message: Buffer) => {
    console.log(`received "${message.toString()}" on topic ${topic}`);
    // your code here
});

publish a message

client.publish('my/topic', 'my message');

Examples

See an example usage implementation in src/example.ts.

API

See API Docs.

TLS

In order to use TLS you need to create key and cert files first. You can use the provided cert/*.pem files for testing purposes, BUT I HIGHLY RECOMMEND to create your own.

To create a TLS/OpenSSL certificate for secure communication, you can follow the instructions provided in the link: How to create TLS/OpenSSL Cert. This guide will walk you through the process of setting up a certificate for local HTTPS development.