linux2mqtt

DISCLAIMER: See credits at the bottom to learn more about the original code for this project.

Publish linux system performance metrics to a MQTT broker. It will also publish Home Assistant MQTT Discovery messages so that (binary) sensors automatically show up in Home Assistant.

This is part of a family of similar tools:

• miaucl/linux2mqtt
• miaucl/docker2mqtt
• miaucl/systemctl2mqtt

It is available as python package on pypi/linux2mqtt.

linux2mqtt is a lightweight wrapper around psutil that publishes CPU utilization, free memory, and other system-level stats to a MQTT broker. The primary use case is to collect system performance metrics for ingestion into Home Assistant (HA) for alerting, reporting, and firing off any number of automations. However, given the minimal nature of this code, it could be used for other purposes as well.

Installation and Deployment

It is available as python package on pypi/systemctl2mqtt.

Pypi package

pip install linux2mqtt 
linux2mqtt --name MyServerName --cpu=60 --vm -vvvvv

Usage

from linux2mqtt import Linux2Mqtt, DEFAULT_CONFIG

cfg = Linux2MqttConfig({ 
  **DEFAULT_CONFIG,
  "host": "mosquitto",
})

try:
  linux2mqtt = Linux2Mqtt(cfg)
  linux2mqtt.connect()
  linux2mqtt.loop_busy()

except Exception as ex:
  # Do something

This will install the latest release of linux2mqtt, create the necessary MQTT topics, and start sending virtual memory and CPU utilization metrics. The MQTT broker is assumed to be running on localhost. If your broker is running on a different host, specify the hostname or IP address using the --host parameter.

linux2mqttrequires Python 3.11 or above. If your default Python version is older, you may have to explicitly specify the pip version by using pip3 or pip-3.

• The --name parameter is used for the friendly name of the sensor in Home Assistant and for the MQTT topic names. If not specified, it defaults to the hostname of the machine.
• Instantaneous CPU utilization isn't all that informative. It's normal for a CPU to occasionally spike to 100% for a few moments and means that the chip is being utilized to its full potential. However, if the CPU stays pegged at/near 100% over a longer period of time, it is indicative of a bottleneck. The --cpu=60 parameter is the collection interval for the CPU metrics. Here CPU metrics are gathered for 60 seconds and then the average value is published to MQTT state topic for the sensor. A good value for this option is anywhere between 60 and 1800 seconds (1 to 15 minutes), depending on typical workloads.
• The --vm flag indicates that virtual memory (RAM) metrics should also be published.
• -vvvvv (five v's) specifies debug-level logging to the console. Reduce the quantity of v's to reduce the logging verbosity.

By default, linux2mqtt will publish system metrics every 30 seconds. This can be changed using the --interval option.

Additional Metrics

Disk Usage

linux2mqtt can publish disk usage metrics using the du option. Multiple du options can be specified to monitor different volumes. Each volume will present as a separate sensor in Home Assistant. The sensor state reports the percentage of total volume space consumed. Additional data (total volume size in bytes, free bytes, and used bytes) are accessible as state attributes on each sensor.

linux2mqtt --name Server1 -vvvvv --cpu=60 --vm --du='/var/spool' --du='/'

Network Throughput

Network throughput (amount of traffic) metrics are also available. Using one or more --net parameters, specify the interface name and the collection interval (as discussed in the CPU metrics documentation), separated by a comma. A separate MQTT topic is created for each interface and each will appear as a separate sensor in HA.

The sensor state equals average throughput of the interface during the collection interval (combining both transmit and receive) in kilobits per second. More detail is available in the state attributes, such as: individual TX and RX rates, number of packets, total bytes sent and received, etc. Except for TX and RX rates, all attribute values are total accumulated values since the interface was reset. Thus, expect to see very large numbers if the interface has been online a while.

linux2mqtt --name Server1 -vvvvv --interval 60 --net=eth0,15

This will publish network throughput information about Server1's eth0 interface to the MQTT broker once every 60 seconds. The sensor state will equal the average network throughput over the previous 15 seconds.

Thermal zones

linux2mqtt can publish temperature metrics for thermal zones using the temp option. Each thermal zone will present as a separate sensor in Home Assistant. The sensor state reports the temperature in °C. Additional data is accessible as state attributes on each sensor.

linux2mqtt --name Server1 -vvvvv --cpu=60 --vm --temp

Fan speeds

linux2mqtt can publish fan speeds using the fan option. Each fan will present as a separate sensor in Home Assistant, but be aware this is only for monitoring which means it is not an actual fan entity but only presents itself as a sensor with no device class and no unit of measurements. The sensor state reports the fan speed in RPM. Additional data is accessible as state attributes on each sensor.

linux2mqtt --name Server1 -vvvvv --cpu=60 --vm --fan

Compatibility

linux2mqtt has been tested to work on CentOS, Ubuntu, and Debian (Raspberry Pi), even tough some features are not available everywhere. Python 3.10 (or above) is recommended.

Running in the Background (Daemonizing)

linux2mqtt runs as a foreground task at the command prompt. In order to run in the program in the background, or automatically at boot, the process has to be daemonized. The easiest way to do this is on a UNIX-like OS (Linux/BSD) is with Supervisor or systemd. Example Supervisor and service configuration file for linux2mqtt is included in the /contrib/ directory.

Using with Home Assistant (HA)

Once linux2mqtt is collecting data and publishing it to MQTT, it's rather trivial to use the data in Home Assistant.

A few assumptions:

• Home Assistant is already configured to use a MQTT broker. Setting up MQTT and HA is beyond the scope of this documentation. However, there are a lot of great tutorials on YouTube. An external broker (or as add-on) like Mosquitto will need to be installed and the HA MQTT integration configured.
• The HA MQTT integration is configured to use homeassistant as the MQTT autodiscovery prefix. This is the default for the integration and also the default for linux2mqtt. If you have changed this from the default, use the --homeassistant-prefix parameter to specify the correct one.
• You're not using TLS to connect to the MQTT broker. Currently linux2mqtt only works with unencrypted connections. Username / password authentication can be specified with the --username and --password parameters, but TLS encryption is not yet supported.

Using the default prefix and a system name of NUC (the name of the server), the following state can be found in the "States" section of Developer Tools in HA:

Lovelace Dashboards

To visualize, use the excellent mini-graph-card custom card for Lovelace dashboards. It's highly-customizable and fairly easy to make great looking charts in HA. Here is a very basic config example of using the metrics produced by linux2mqtt to display the past 12 hours of CPU and memory utilization on an Intel NUC server:

entities:
  - entity: sensor.nuc_cpu
    name: CPU Utilization
    show_legend: true
    show_line: true
    show_points: false
  - entity: sensor.nuc_virtual_memory
    name: Memory Utilization
    show_legend: true
    show_line: true
    show_points: false
hours_to_show: 12
line_width: 2
lower_bound: 0
name: NUC System Metrics
points_per_hour: 6
show:
  labels: false
  labels_secondary: false
type: 'custom:mini-graph-card'
upper_bound: 100

Documentation

Using mkdocs, the documentation and reference is generated and available on github pages.

Dev

Setup the dev environment using VSCode, it is highly recommended.

python -m venv .venv
source .venv/bin/activate
pip install -r requirements_dev.txt

Install pre-commit

pre-commit install

# Run the commit hooks manually
pre-commit run --all-files

Following VSCode integrations may be helpful:

• ruff
• mypy
• markdownlint

Releasing

It is only possible to release a final version on the master branch. For it to pass the gates of the publish workflow, it must have the same version in the tag, the setup.cfg, the bring_api/__init__.py and an entry in the CHANGELOG.md file.

To release a prerelease version, no changelog entry is required, but it can only happen on a feature branch (not master branch). Also, prerelease versions are marked as such in the github release page.

Credits

This is a detached fork from the repo https://github.com/jamiebegin/linux2mqtt, which does not seem to get evolved anymore.

This project is intended to be an alternative to the (very good) Glances project. The primary design difference is that the Glances integration into Home Assistant relies on periodically polling a RESTful API. However, the pub/sub model of MQTT--which is already widely used in the home automation community--is an ideal fit for real-time reporting of this type of data. Additionally linux2mqtt can be very lightweight because it omits the GUI and alerting elements of Glances (which are redundant when used in conjunction with HA).