This mod simply looks for a file periodically, which must be created by touch(1) or something similar, and owned by the same user who is running the Minetest server. This file simply serves as a sort of flag.

If found, the file is immediately deleted, and pop-up warnings are issued to all players on the server that it will be rebooting soon.

This mod must be listed in secure.trusted_mods (assuming mod security is enabled) in order for the os.remove() function to work.

The pop-up function is provided by kaeza's notice mod, from here:

https://github.com/kaeza/minetest-kaeza_misc