mqtt-repeater.js

var mqtt = require('mqtt'),
    tlsReader = require('./lib/tls-reader'),
    isUndefined = require('./lib/is-undefined'),
    config1 = require('./local-setting-mqtt1.json'),
    config2 = require('./local-setting-mqtt2.json');

if (!isUndefined(config1.keyPath)) tlsReader(config1);
if (!isUndefined(config2.keyPath)) tlsReader(config2);

var client1 = mqtt.connect(config1);
var client2 = mqtt.connect(config2);

var sentMessagesFrom1 = [];
var sentMessagesFrom2 = [];

function popSentMessage(client, messageData) {
    var sentMessages = (client === client1) ? sentMessagesFrom2 : sentMessagesFrom1;
    for (var i = 0; i < sentMessages.length; i++) {
        if (sentMessages[i].topic === messageData.topic &&
            sentMessages[i].message.toString() == messageData.message.toString()) {
            var sentMessage = sentMessages[i];
            sentMessages.splice(i, 1);
            return sentMessage;
        }
    }
    return null;
}

function pushSentMessage(client, messageData) {
    if (client === client1) {
        sentMessagesFrom1.push(messageData);
    } else {
        sentMessagesFrom2.push(messageData);
    }
}

function debugSentMessages() {
    if (sentMessagesFrom1.length > 0) {
        console.log("sentMessagesFrom1: ");
        for (var i = 0; i < sentMessagesFrom1.length; i++) {
            console.log(sentMessagesFrom1[i]);
        }
    }

    if (sentMessagesFrom2.length > 0) {
        console.log("sentMessagesFrom2: ");
        for (var i = 0; i < sentMessagesFrom2.length; i++) {
            console.log(sentMessagesFrom2[i]);
        }
    }
}

function publish(client, topic, message) {
    var messageData = {
        topic: topic,
        message: message,
        created: new Date()
    };
    if (popSentMessage(client, messageData) !== null) {
        return false;
    }
    debugSentMessages();
    pushSentMessage(client, messageData);
    client.publish(topic, message);
    return true;
}

client1.on('connect', function() {
    console.log('connected to ' + this.options.host);
    this.subscribe(this.options.subscribedTopic);
});

client1.on('message', function(topic, message, packet) {
    console.log(this.options.host + " says: " + message.toString());
    publish(client2, topic, message);
});

client2.on('connect', function() {
    console.log('connected to ' + this.options.host);
    this.subscribe(this.options.subscribedTopic);
});

client2.on('message', function(topic, message, packet) {
    console.log(this.options.host + " says: " + message.toString());
    publish(client1, topic, message);
});