A lightweight exporter that reads sensor data from an MQTT broker and exposes it as Prometheus metrics. Designed for seamless integration with Grafana Stack Components like Loki/Promtail for monitoring and logging. Part of my upcoming Smart Garden project to automate and monitor garden systems using IoT devices.

This is by far not meant or designed to be a generic mqtt-to-prometheus exporter. I aim to use this only for my smart gardening project. A reasonable exporter that could fit your needs better, if you want a somewhat generic approach: kpetremann/mqtt-exporter

A selection of tools and software needed:

• Docker
• Docker Compose
• Python 3.9
• MQTT Broker (e.g., Mosquitto)
• Prometheus
• Grafana
• Promtail for log scraping (optional)

You can use the docker images or build it yourself, choose for your comfort.

Coming soon!

1. Clone the repository:

   git clone https://github.com/Mawiguk0/mqtt-to-prometheus.git
   cd mqtt-to-prometheus

2. Build and run the Docker containers:

   docker-compose up --build

The project uses environment variables for configuration:

• MQTT_BROKER: Address of the MQTT broker.
• MQTT_PORT: Port of the MQTT broker (default: 1883).
• MQTT_TOPIC: MQTT topic to subscribe to.
• PROMETHEUS_PORT: Port for the Prometheus metrics server (default: 8000).
• RETRY_INTERVAL: Interval between retry attempts to connect to the MQTT broker (default: 5 seconds).

Variable coming from python-json-logger, useful for some:

• LOG_LEVEL: Set the desired logging level DEBUG, INFO, WARNING, ERROR (default: INFO)

1. Start the service:

   docker-compose up --build

2. Access Prometheus metrics: Open your browser and navigate to http://localhost:8000/metrics.

3. View logs in Grafana: Configure Grafana to read logs from Loki and explore the logs using the "Explore" feature.

The project includes a health check script to verify the service's health. The Docker container is configured to run this script periodically.

Logs are structured using JSON format and are compatible with Grafana Loki for easy log aggregation and querying. The promtail service is used to scrape logs from Docker containers and send them to Loki.

Consult Logging Documentation for further insights.

The following metrics are exposed:

• mqtt_humidity: Humidity from MQTT topic
• mqtt_temperature: Temperature from MQTT topic
• mqtt_adc: ADC value from MQTT topic
• mqtt_battery: Battery level from MQTT topic
• mqtt_rssi: RSSI from MQTT topic
• mqtt_snr: SNR from MQTT topic
• mqtt_pferror: Packet Frequency Error from MQTT topic
• mqtt_packet_size: Packet Size from MQTT topic
• mqtt_last_data_received_timestamp: Timestamp of the last data received

The docker-compose.yml file sets up the following services:

• mqtt_to_prometheus: The main service that reads MQTT data and exposes Prometheus metrics.
• prometheus: The Prometheus service for scraping and storing metrics.
• promtail: The Promtail service for log scraping.

• MQTT Connection Issues: Ensure the MQTT broker address and port are correctly configured.
• Metrics Not Updating: Check the MQTT topic for correct data and ensure the Prometheus scrape interval is appropriate.
• Log Issues: Verify that Promtail is correctly configured to scrape Docker logs.

For detailed information about the architecture and decision-making process behind this project, please refer to the following documents:

Architecture Documentation
Architecture Decision Records
What is an ADR? https://adr.github.io/

Contributions are welcome! Please fork the repository and submit pull requests.

This project is licensed under the MIT License. See the LICENSE file for details.