PascalUlor/mqtt-broker

This is a basic implementation of an iot message broker using MQTT and GraphQL

A progressive Node.js framework for building efficient and scalable server-side applications.

Description

IOT APP This is a basic implementation of an iot message broker using MQTT and GraphQL Nest framework TypeScript starter repository.

Installation

$ npm install

Running the app

# development
$ npm run start

# watch mode
$ npm run start:dev

# production mode
$ npm run start:prod

Implementation Approach

The request and response data are stored in memory in a mock database. When a request is made the publisher publishes the request then the subscriber writes the request to a mock database.

Technology Stack

Built With

• Node.js - Javascript runtime
• NestJs- Server-side Framework
• ApolloGraphQl - GraphQL Communication Layer
• MQTT - NPM MQTT package
• Mosquitto - MQTT Broker

GraphQL API Architecture

http://localhost:3000/graphql

To send a message to mqtt broker

Mutation

mutation addMessage ($newMessageData: MessageInput!) {
   addMessage (newMessageData: $newMessageData) {
     title,
     description
   }
 }

Pass the Query Variables as follows

{
  "newMessageData": {
    "id": "124",
    "title": "dim4 sample",
    "description":"sample description"
  }
}

Query

query message {
   message(id: "124") {
    title
   }
 }

Query to get all messages and limit number of response NOTE passing limit:0 would return all messages limit: 10 returns 10 messages

query allMessages {
   allMessages(limit: 0) {
    title
   }
 }

Improvements

1. Setup a database connection and log messages from publisher to DB
2. Write unit/integration tests

Test

# unit tests
$ npm run test

# e2e tests
$ npm run test:e2e

# test coverage
$ npm run test:cov

Support

Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support by the amazing backers. If you'd like to join them, please read more here.

Stay in touch

• Author - Pascal Ulor
• Website - https://www.pascalulor.com/

License

Nest is MIT licensed.