PresMon

Project status: beta.

Computer presence monitoring via keyboard events and Home Assistant binary_sensor presence and hotkey integration.

PresMon is a python daemon (installable as systemd service) that monitors a computer for input activity, and generates a presence signal. The presence information is publish via MQTT and is then available as binary_sensor within Home Assistant.

Home Assistant's mqtt auto-discovery is supported, a presence sensor (type binary_sensor, device_class presence)binary_sensor.<homeassistant: <entity_name>_presence is automatically generated in Home Assistant. The name can be configured in the config file presmon.yaml, and is the computer's hostname by default.

Additionally keyboard-hotkeys can be exported as Home Assistant binary sensors of name binary_sensor.<homeassistant: <entity_name>_key_<keyname>. Use your keyboard to control your Home Assistant setup. Buttons can be used in button mode (HA binary sensor is on while keyboard hotkey is pressed), or flipflop mode (first time hotkey is pressed, HA binary sensor switches on, next time hotkey is pressed, binary sensor switches off). See presmon_default.yaml for examples and more information.

Configuration

• Copy presmon-default.yaml to presmon.yaml and customize.
• For systemd service installations, adapt presmon.service

Configuration file presmon.yaml

• At minimum, configure mqtt: broker.
• Check which services should be active
• After testing, increase input: timeout to a higher value (e.g. 300)

Installation

Requirements: ruamel.yaml, paho-mqtt, keyboard, bluepy [optional, Linux only]. mouse [optional, Linux, Windows, problems with systemd] Since presmon needs to run as root, the dependencies must be installed for the root user.

presmon needs to be run as root, either as systemd service, or via

sudo python presmon.py [--help] [-k]

Mac: the terminal that runs this script needs Mac OS Catalina 'Accessibility' right, otherwise this will just crash.

Hints for automatic start

• There seems to be a problem with the mouse module and running presmon.py as systemd service. The process crashes on mouse events. So only use this with systemd, if the mouse option is set to false in presmon.yaml.
• For Linux, Mac it might be useful to allow presmon.py to run with sudo without password. That can be achieved by using visudo and adding a line:

<your-username> ALL = NOPASSWD: <full-path-to-script>/presmon.py

presmon.py needs to be executable (chmod a+x presmon.py).

• Create an autostart script (requires the visudo entry in order to run without passwordl-prompt), you can modify and rename start.default.sh; edit it and rename it to start.sh:

#!/bin/bash
sudo <full-path-to-script>/presmon.py &

and use your desktop environments autostart-feature to start this script on login. Some desktops (e.g. Gnome) need a .desktop file for autostart to recognize the script. You can modify and rename the template PresMon.default.desktop. Rename it to PresMon.desktop and copy it to an applications directory, e.g. ~/.local/share/applications/. Then update the database with update-desktop-database ~/.local/share/applications/.

macOS autostart

For Macs, a few extra things are required:

• Use sudo visudo to insert (replace username and path) after line %admin ALL = (ALL) ALL:

<your-username> ALL=(ALL)  NOPASSWD: /<full-path-to-script>/presmon.py

• Make sure presmon.py is executable (chmod a+x presmon.py)
• Automator will use Catalina's/Big Sur's system /usr/bin/python3. So the dependencies (ruamel.yaml, paho-mqtt, keyboard) need to be installed for the system python (using sudo /usr/bin/pip3 install ruamel.yaml paho-mqtt keyboard)
• Use the macOS automator app to create a new 'Application'.
• Add 'shell script'
• Paste and adapt: sudo /<full-path-to-script>/presmon.py &>/dev/null &. The redirection of the output suppresses the eternally spinning gear of Automator.

• Save your application
• Use Control Panel Security / Privacy to add your newly created Automator application to 'Accessibility' (which allows the input monitoring).
• Use Control Panel user administration to add a new startup item, and add the application that was created with automator.

History

• 2021-01-02: switched from pyyaml to ruamel.yaml (preserves comments on load/dump cycle), make first-time MAC into UUID to prevent MAC randomization to mess up device-ids.

Notes

• Windows has not been tested, but might work.
• The keyboard library on Linux sometimes registers mouse clicks, depending on context. Currently, the key-release hotkey handling is broken (workaround via timer implemented)
• The mouse lib causes a SEGV crash, if run as systemd service. Cause not yet investigated. Works fine, if started via autostart.