MqttGen is an MQTT message generator.

MqttGen can be used to create MQTT message flow to test applications using the MQTT protocol. It was created to test the jMQTT Jeedom plugin.

MqttGen comes with two tools:

• mqttgen which is a kind of MQTT simulator allowing to send and receive messages. Behaviour is defined in a JSON input file.
• mqttplay which allows to replay a MQTT flow previously recorded thanks to an MQTT client such as mosquitto_sub.

The recommended way to install MqttGen is through Composer.

composer require domotruc/mqttgen

vendor/bin/mqttgen your_json_input_file.json

To run the provided example, execute the following from the directory containing the composer.json file:

vendor/bin/mqttgen vendor/domotruc/mqttgen/topics.json

Following file is assumed to be in the same directory as your composer.json file.

<?php

require __DIR__ . '/vendor/autoload.php';

try {
    $filename = 'vendor/domotruc/mqttgen/topics.json';
    $mqttgen = new MqttGen\MqttGen($filename);
    do {
        $mqttgen->nextMessage();
        sleep(2);
    } while (true);
}
catch (\Exception $e) {
    print($e->getMessage() . PHP_EOL);
}

The library is provided with an example of JSON input file topics.json that gives and explains all the options.

Once the libray is installed using composer (see above), file topics.json can be found in the vendor/domotruc/mqttgen directory.

This file generates the following MQTT flows:

2018-06-24 08:38:33.171 boiler/status "online"
2018-06-24 08:38:35.173 boiler/brand "undisclosed brand"
2018-06-24 08:38:37.172 boiler/uptime 94002
2018-06-24 08:38:39.173 boiler/date {"time":{"value":"08:38:39"},"date":{"value":"24.06.2018"}}
2018-06-24 08:38:41.175 boiler/ping "ping"
2018-06-24 08:38:43.176 boiler/burner "off"
2018-06-24 08:38:45.174 boiler/temp 89.5
2018-06-24 08:38:47.175 boiler/ext_temp 20.157077
2018-06-24 08:38:49.176 boiler/hw/temp 50.5
2018-06-24 08:38:51.175 boiler/info {"device":"ESP32"}
2018-06-24 08:38:53.179 boiler/temperatures {"device":"tronic","sensorType":"Temperature","values":[9.710066,84.988007,22.03299]}
2018-06-24 08:38:55.179 boiler/power 1.01
2018-06-24 08:38:57.180 boiler/lux 1114.44

It is also possible to interact with mqttgen. Given the topics.json example file, the following command:

mosquitto_pub -t 'boiler/hw/setpoint/get' -m ''

makes mqttgen send the following message:

2018-06-24 08:47:46.127 boiler/hw/setpoint 50

Then:

mosquitto_pub -t 'boiler/hw/setpoint/set' -m '65'

updates the internal mqttgen setpoint value. Sending again the get message:

mosquitto_pub -t 'boiler/hw/setpoint/get' -m ''

makes mqttgen send the following message:

2018-06-24 08:47:46.127 boiler/hw/setpoint 65

mqttplay allows to replay an MQTT flow previously recorded thanks to the following command:

mosquitto_sub -t "#" -v| xargs -d$'\n' -L1 bash -c 'date "+%T.%3N $0"' | tee flow.txt

which gives a file such as:

15:27:10.358 N/pvinverter/20/Ac/L1/Voltage {"value": 240.59999999999999}
15:27:10.386 N/pvinverter/20/Ac/L1/Power {"value": 1821.8742186612658}
15:27:10.415 N/pvinverter/20/Ac/L1/Energy/Forward {"value": 4272.6587533761876}
15:27:10.496 N/pvinverter/20/Ac/L1/Current {"value": 3.9399999999999999}

To run the provided example, execute the following from the directory containing the composer.json file:

vendor/bin/mqttplay vendor/domotruc/mqttgen/flow.txt

Following file is assumed to be in the same directory as your composer.json file.

<?php

use  MqttPlay\MqttPlay;

require __DIR__ . '/vendor/autoload.php';

try {
    $filename = 'vendor/domotruc/mqttgen/flow.txt';
    $mqttPlay = new MqttPlay($filename, true, ' ', 'localhost', 1883, 1);
    while (($msg = $mqttPlay->nextMessage()) != null) {
        print($msg[MqttPlay::S_TIME ] . " " . $msg[MqttPlay::S_TOPIC] . " " . $msg[MqttPlay::S_PAYLOAD] . PHP_EOL);
    }
}
catch (\Exception $e) {
    print($e->getMessage() . PHP_EOL);
}

The MQTT flow can also be passed directly as an array, which gives:

<?php

use  MqttPlay\MqttPlay;

require __DIR__ . '/vendor/autoload.php';

$mqtt_flow = array(
    array('15:27:10.358', 'N/pvinverter/20/Ac/L1/Voltage', '{"value": 240.59999999999999}'),
    array('15:27:10.386', 'N/pvinverter/20/Ac/L1/Power', '{"value": 1821.8742186612658}'),
    array('15:27:10.415', 'N/pvinverter/20/Ac/L1/Energy/Forward', '{"value": 4272.6587533761876}'),
    array('15:27:10.496', 'N/pvinverter/20/Ac/L1/Current', '{"value": 3.9399999999999999}')
);

try {
    $mqttPlay = new MqttPlay($mqtt_flow, true, ' ', 'localhost', 1883, 1);
    while (($msg = $mqttPlay->nextMessage()) != null) {
        print($msg[MqttPlay::S_TIME ] . " " . $msg[MqttPlay::S_TOPIC] . " " . $msg[MqttPlay::S_PAYLOAD] . PHP_EOL);
    }
}
catch (\Exception $e) {
    print($e->getMessage() . PHP_EOL);
}