From GitHub - pimoroni/clean-shutdown: Python daemon to watch a GPIO pin and trigger a clean shutdown.
Parasitic Shutdowns
Be aware that altering the state of trigger_pin can throw you in a scenario where your Pi shuts down right away upon boot, if a process, dtoverlay, or HAT EEPROM, just to name a few possibilities, pulls it low on boot (or set it as an output, which implies it being driven low initially).
If this occurs right after you plugged a HAT, then try booting without it attached, and disable the cleatshutd service with:
sudo systemctl disable cleanshutd
There is another way, which is provided as an emergency solution for scenarios where reaching the bash prompt is not possible (because the Pi shuts down before you get a chance to do so).In such cases, or as an alternative to the above, you may add the following to your /boot/config.txt file from another computer:
disable_cleanshutd=1