Forward MQTT messages to HTTP.
This simple, but highly configurable script subscribes to one or more MQTT topics and makes a HTTP request for every message it receives. This allows you to use MQTT messages as trigger for APIs that don't support MQTT via services like Zapier's Webhook or IFTTT's Maker Channel.
Deploy directly to Heroku or clone the repository and run it in any current Node.js environment:
To test you can use a public MQTT broker like mqtt://test.mosquitto.org and the DEBUG_* variables. Rename debug.env to .env for an example that publishes a JSON stringified object with the current time every 5 seconds and skips the actual request.
Configure the MQTT connection and topic to subscribe to and the HTTP requests to make via environment variables. The script uses dotenv to load these from a file if you like. Be aware that some of the variables can or must be formatted as JSON strings.
The following variables can be set:
| Variable | Required | Description |
|---|---|---|
MQTT_URL |
Yes | MQTT broker URL to connect to. See https://www.npmjs.com/package/mqtt#connect |
MQTT_USERNAME |
No | MQTT broker username. See https://www.npmjs.com/package/mqtt#mqttclientstreambuilder-options |
MQTT_PASSWORD |
No | MQTT broker password. See https://www.npmjs.com/package/mqtt#mqttclientstreambuilder-options |
MQTT_CONNECT |
No | MQTT broker connection options. Formatted as JSON String. See https://www.npmjs.com/package/mqtt#mqttclientstreambuilder-options |
MQTT_TOPIC |
Yes | MQTT topic(s) to subscribe. Either a single topic or an Array or Object formatted as JSON String. See https://www.npmjs.com/package/mqtt#subscribe |
MQTT_SUBSCRIBE |
No | MQTT subscribe options. Formatted as JSON String. See https://www.npmjs.com/package/mqtt#subscribe |
HTTP_URL |
Yes | HTTP request URL. Compiled as Handlebars template and executed with the topic and message as data. See https://www.npmjs.com/package/request#requestoptions-callback and http://handlebarsjs.com/ |
HTTP_JSON |
No | Set to a truthy string (e.g. 1) to set the request option json to true and body to an object with the topic and message (as object, if available). See https://www.npmjs.com/package/request#requestoptions-callback |
HTTP_REQUEST |
No | HTTP request options. Compiled as Handlebars template and executed with the topic and message as data. Use the stringify helper if needed to output a JSON String. See https://www.npmjs.com/package/request#requestoptions-callback |
DEBUG_LOG |
No | Set to a truthy string (e.g. 1) to write debug logs to the console. |
DEBUG_PUBLISH |
No | Set to a integer string (e.g. 5000) to publish dummy topics to the broker at this interval. |
DEBUG_MESSAGE |
No | Message to publish. Defaults to a JSON formatted object with time set to Date.toString(). |
DEBUG_NOOP |
No | Set to a truthy string (e.g. 1) to not actually make the HTTP request. |