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MQTT adapter

MQTT adapter provides an MQTT API for sending and receiving messages through the platform.

Configuration

The service is configured using the environment variables presented in the following table. Note that any unset variables will be replaced with their default values.

Variable	Description	Default
MF_MQTT_ADAPTER_LOG_LEVEL	MQTT adapter log level	error
MF_MQTT_INSTANCE_ID	ID of MQTT adapter instance
MF_MQTT_ADAPTER_PORT	Service MQTT port	1883
MF_MQTT_ADAPTER_WS_PORT	WebSocket port	8880
MF_NATS_URL	NATS instance URL	nats://localhost:4222
MF_MQTT_ADAPTER_REDIS_PORT	Redis port	6379
MF_MQTT_ADAPTER_REDIS_HOST	Redis host	localhost
MF_MQTT_ADAPTER_REDIS_PASS	Redis pass	mqtt
MF_MQTT_ADAPTER_REDIS_DB	Redis db	0
MF_MQTT_ADAPTER_ES_PORT	Event stream port	6379
MF_MQTT_ADAPTER_ES_HOST	Event stream host	localhost
MF_MQTT_ADAPTER_ES_PASS	Event stream pass	mqtt
MF_MQTT_ADAPTER_ES_DB	Event stream db	0
MF_MQTT_CONCURRENT_MESSAGES	Number of messages that can be concurrently exchanged	100
MF_THINGS_URL	Things service URL	localhost:8181
MF_MQTT_ADAPTER_CLIENT_TLS	Flag that indicates if TLS should be turned on	false
MF_MQTT_ADAPTER_CA_CERTS	Path to trusted CAs in PEM format

Deployment

The service is distributed as Docker container. The following snippet provides a compose file template that can be used to deploy the service container locally:

version: "2"
services:
  mqtt:
    image: mainflux/mqtt:[version]
    container_name: [instance name]
    ports:
      - [host machine port]:[configured port]
    environment:
      MF_THINGS_URL: [Things service URL]
      MF_NATS_URL: [NATS instance URL]
      MF_MQTT_ADAPTER_LOG_LEVEL: [MQTT adapter log level]
      MF_MQTT_INSTANCE_ID: [ID of MQTT adapter instance]
      MF_MQTT_ADAPTER_PORT: [Service MQTT port]
      MF_MQTT_ADAPTER_WS_PORT: [Service WS port]
      MF_MQTT_ADAPTER_REDIS_PORT: [Redis port]
      MF_MQTT_ADAPTER_REDIS_HOST: [Redis host]
      MF_MQTT_ADAPTER_REDIS_PASS: [Redis pass]
      MF_MQTT_ADAPTER_REDIS_DB: [Redis db]
      MF_MQTT_ADAPTER_ES_PORT: [Event stream port]
      MF_MQTT_ADAPTER_ES_HOST: [Event stream host]
      MF_MQTT_ADAPTER_ES_PASS: [Event stream pass]
      MF_MQTT_ADAPTER_ES_DB: [Event stream db]
      MF_MQTT_CONCURRENT_MESSAGES: [Number of messages that can be concurrently exchanged]
      MF_MQTT_ADAPTER_CLIENT_TLS: [Flag that indicates if TLS should be turned on]
      MF_MQTT_ADAPTER_CA_CERTS: [Path to trusted CAs in PEM format]

To start the service outside of the container, execute the following shell script:

# download the latest version of the service
go get github.com/mainflux/mainflux

cd $GOPATH/src/github.com/mainflux/mainflux/mqtt

# install dependencies
npm install

# set the environment variables and run the service
MF_THINGS_URL=[Things service URL] MF_NATS_URL=[NATS instance URL] MF_MQTT_ADAPTER_LOG_LEVEL=[MQTT adapter log level] MF_MQTT_INSTANCE_ID=[ID of MQTT adapter instance] MF_MQTT_ADAPTER_PORT=[Service MQTT port] MF_MQTT_ADAPTER_WS_PORT=[Service WS port] MF_MQTT_ADAPTER_REDIS_PORT=[Redis port] MF_MQTT_ADAPTER_REDIS_HOST=[Redis host] MF_MQTT_ADAPTER_REDIS_PASS=[Redis pass] MF_MQTT_ADAPTER_REDIS_DB=[Redis db] MF_MQTT_ADAPTER_ES_PORT=[Event stream port] MF_MQTT_ADAPTER_ES_HOST=[Event stream host] MF_MQTT_ADAPTER_ES_PASS=[Event stream pass] MF_MQTT_ADAPTER_ES_DB=[Event stream db] MF_MQTT_CONCURRENT_MESSAGES=[Number of messages that can be concurrently exchanged] MF_MQTT_ADAPTER_CLIENT_TLS=[Flag that indicates if TLS should be turned on] MF_MQTT_ADAPTER_CA_CERTS=[Path to trusted CAs in PEM format] node mqtt.js ..

Usage

To use MQTT adapter you should use channels/<channel_id>/messages. Client key should be passed as user's password. If you want to use MQTT over WebSocket, you could use Paho client:

<!DOCTYPE html>
<html>
  <head>
  <meta http-equiv="Content-Type" content="text/html;charset=utf-8"/>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/paho-mqtt/1.0.2/mqttws31.min.js" type="text/javascript"></script>
  <script type="text/javascript">
    var wsbroker = "localhost";  //mqtt websocket enabled broker
    var wsport = 443 // port for above

    var client = new Paho.MQTT.Client(wsbroker, Number(wsport), '');

    client.onConnectionLost = function (responseObject) {
      console.log("connection lost: " + responseObject.errorMessage);
    };

    client.onMessageArrived = function (message) {
      console.log("Msg", message.destinationName, ' -- ', message.payloadString);
    };

    var options = {
      timeout: 3,
      userName: "<thing_id>",   // Replace <:your_thing_id>
      password: "<thing_key>",  // Replace <:your_thing_key>
      useSSL: true,
      onSuccess: function () {
        console.log("mqtt connected");
        // Connection succeeded; subscribe to our topic, you can add multile lines of these
        client.subscribe('channels/<channel_id>/messages', {qos: 1});  // Replace <:your_channel_id>

        // use the below if you want to publish to a topic on connect
	      var payload = [
	        {
	          "bn":"e35b157f-21b8-4adb-ab59-9df21461c815",
	          "bt":1.276020076001e+09,
	          "bu":"A",
	          "bver":5,
	          "n":"voltage",
	          "u":"V",
	          "v":120.1
	        },
	        {
	          "n":"current",
	          "t":-5,
	          "v":1.2
	        },
	        {
	          "n":"current",
	          "t":-4,
	          "v":1.3
	        }
	      ];
        var message = new Paho.MQTT.Message(JSON.stringify(payload));
        message.destinationName = "channels/<channel_id>/messages";  // Replace <:your_channel_id>
        client.send(message);
      },
      onFailure: function (message) {
        console.log("Connection failed: " + message.errorMessage);
      }
    };

    function init() {
      client.connect(options);
    }

  </script>
  </head>
  <body onload="init();">
  </body>

</html>

7.0 KiB Raw Blame History

MQTT adapter

Configuration

Deployment

Usage

7.0 KiB

Raw Blame History