ember install ember-mqttjs

app.import('node_modules/mqtt/dist/mqtt.min.js',{
  using: [
    { transformation: 'amd', as: 'mqttjs' }
  ]
});

import { inject as service } from '@ember/service';
...
@service mqtt;

this.mqtt.connect('wss://test.mosquitto.org:8081').then( () => {
    // Do stuff on connection established
});
this.mqtt.on('mqtt-message', (sTopic, sMessage) => {
    // Do stuff with topic and message parameters
});

this.mqtt.subscribe('presence').then( (oGranted)=>{
    // Do stuff after succesfully subscription to mqttTopic
});

this.mqtt.publish('presence', 'Hello').then( () => {
    // Do stuff after successfully published message
});

this.mqtt.unsubscribe('presence').then( (oGranted)=>{
    // Do stuff after succesfully unsubscription to mqttTopic
});

this.mqtt.on('mqtt-message', (sTopic, sMessage) => {
    // Do stuff with topic and message parameters
});