Sensorer

Sensorer, aka "sensors", reads sensor data from MQTT and makes it available for scraping to Prometheus. It's a Hemtjanst exporter.

This package was written with Go 1.14.

Installation

• go install github.com/hemtjanst/sensorer/cmd/sensorer

Development

• git clone github.com/hemtjanst/sensorer
• go mod download

Exported metrics

There are two endpoints:

• /metrics which contains metrics internal to Sensorer, like HTTP request statistics, memory utilisation etc
• /sensors with the sensor metrics

Which metrics are exported depends on the features the device announces. Every exported metric has a label named source which holds the device's MQTT topic.

• currentTemperature: gauge sensors_temperature_celsius
• currentRelativeHumidity: gauge sensors_humidity_relative_percent
• contactSensorState: gauge sensors_contact_state
• currentPower: gauge sensors_power_current_watts
• currentPowerProduced: gauge sensors_power_produced_current_watts
• energyUsed: counter sensors_power_total_kwh
• energyProduced: counter sensors_power_produced_total_kwh
• currentVoltage: gauge sensors_power_current_voltage
• currentAmpere: gauge sensors_power_current_ampere
• batteryLevel: gauge sensors_battery_level_percent
• precipitation gauge sensors_precipitation_mm_per_hour
• airPressure gauge sensors_air_pressure_hpa
• windSpeed gauge sensors_wind_speed_meters_per_second
• windDirection gauge sensors_wind_direction_degrees
• globalRadiation gauge sensors_global_radiation_watts_per_square_meter

Built-in sensors

A time series is computed for humiture, also known as the "feels like" temperature: sensors_humiture_celsius.

Two time series are computed based on location.lat and location.long, respectively sensors_sunrise_time_seconds and sensors_sunset_time_seconds. A third time series, sensors_daylight returns 1 if the current time is between sunrise and sunset, and 0 otherwise.

Options

A number of options can be passed at startup in order to configure the behaviour. Most importantly are probably -exporter.listen-address and -mqtt.address. These let you configure on what host:port combination the metrics are exported and on what host:port combination the MQTT broker can be found.

Issue a sensorer -help for all possible options.

Caveats

Depending on the Prometheus scrape time and how certain contact sensors report in, it's very possible that you would not be able to see something like a door opening and closing in fairly rapid succession reflected in Prometheus. As such you must not rely on this data for the purposes of home security.