Dialogflow connect to MQTT broker using Firebase? - firebase

Question

I'm trying to use the Cloud Functions for Firebase to make a Dialogflow intent result in an MQTT message being published. I've managed to get the data I needed and all I still am not able to accomplish is:
Establishing a connection to the MQTT broker;
Publishing to said broker.
As the second one requires the former, it is not my concern yet.
The way I see it is: either my code is wrong or MQTT is included in what Firebase calls "external network". And I'm here, mainly, to make sure I don't upgrade to a paid plan for nothing.
index.js:
'use strict';
const functions = require('firebase-functions');
const { WebhookClient, Card, Suggestion } = require('dialogflow-fulfillment');
var mqtt = require('mqtt');
process.env.DEBUG = 'dialogflow:debug';
const HOST = 'broker.mqttdashboard.com';
const PORT = 1883;
const TOPIC = 'topic/voice_recog';
exports.dialogflowFirebaseFulfillment = functions.region('europe-west1').https.onRequest((request, response) => {
const agent = new WebhookClient({ request, response });
try {
function publishParameter(agent) {
let message = agent.parameters.param_test;
return publishToMqtt(message).then((output) => {
agent.add(output);
}).catch(error => {
agent.add('error from publishToMqtt');
});
}
let intentMap = new Map();
intentMap.set('Repeat parameter', publishParameter);
agent.handleRequest(intentMap);
}
catch (err) {
console.error(err);
agent.add(err.message);
agent.send_();
}
});
function publishToMqtt(message) {
console.log("------------------------------");
console.log("Topic: \""+TOPIC+"\"");
console.log("Message: \""+message+"\"");
console.log("------------------------------");
return new Promise((resolve, reject) => {
var options = {
port: PORT,
host: HOST,
clientId: 'mqttjs_' + Math.random().toString(16).substr(2, 8),
keepalive: 60,
reconnectPeriod: 1000,
protocolId: 'MQIsdp',
protocolVersion: 3,
clean: true,
encoding: 'utf8'
};
var client = mqtt.connect("mqtt://"+HOST, {port: PORT});
// is not executed
client.on('connect', function () {
console.log('client connected');
});
// is not executed
client.publish(TOPIC, message, {}, function (err) {
console.log("Tried publishing \""+message+"\" to \""+TOPIC+"\".");
if (err) {
console.log("But the future refused to change:" + err);
reject();
}
else {
resolve(message);
client.end();
clearTimeout(noResp);
}
});
let noResp = setTimeout(() => {
console.log("No connection"); // always gives this result
reject();
client.end();
}, 5000);
});
}
package.json:
{
"name": "assistant-to-mqtt",
"description": "publishes intent parameter to MQTT broker",
"engines": {
"node": "8"
},
"version": "0.0.1",
"private": true,
"scripts": {
"start": "firebase serve --only functions:publish_mqtt",
"deploy": "firebase deploy --only functions:publish_mqtt"
},
"dependencies": {
"actions-on-google": "^2.1.3",
"dialogflow-fulfillment": "^0.4.1",
"firebase-admin": "^5.12.1",
"firebase-functions": "^2.2.1",
"mqtt": "^2.13.0"
}
}
All help is appreciated. Thank you.
EDIT: The log.

Answer 1

You are actually using a MQTT Broker which is treated as an external access URL by Firebase. Try enabling the billing as described here.