Allow update on shutdown w/ Plymouth integration

[TobiPeterG]

Hey there,

it'd be cool if this script would support the functionality of this script as well, so that there's "one to rule them all".

This means:

• automatically search for updates at shutdown (of snaps, flatpaks, repo packages, aur packages
• update at shutdown only, not at reboots
• use systemd to ensure that the update isn't killed after a timeout (default 1min30)
• graphical integration with progress bars using plymouth (only if Plymouth is present)
• only apply updates when battery is charged to 50% and connected to power (notebook only)

This can be accomplished by using a systemd service that a) is started at startup b) has it's dependency services declared c) prevents those from being stopped at shutdown before the script ends A specific implementation of such service can be found at the repo above

Also, it's required to override a systemd script to prevent the script from being killed while running. This has the disadvantage of the system potentially hanging endlessly, should there be any other way, recommendations are always welcome.

The updater would have to support snaps as well, to be completely on function parity with the script above. This could be done by using pamac to update the system. In this case, the progress bar implementation for plymouth is already existing in the script above.

Should I have missed anything, feel free to get in touch! :)

[lectrode]

Comment to track progress of implementation of request.

Current list of prerequisites/tasks to implement the main functionality requested:

• [ ] Support updating snap packages (update only, snaps do not support orphan package cleanup)
• [ ] Option to disable updates when on battery power below 50% (likely include configurable %)
• [ ] Option to send update messages/progress to plymouth if available
• [ ] Option and service files for running script at ~startup~, shutdown
  • [ ] Support being a part of shutdown process, instead of just initiating it (feasible?)
  • [ ] find way to initiate shutdown without re-running script...

The trickiest part seems like the shutdown process. In the past I've setup a desktop shortcut to be the shutdown command (shortcut runs the script in full screen, which is pre-configured to be allowed to run with sudo without a password, and the script eventually shuts down or restarts the computer when finished). Having the script be a part of the shutdown process instead of initiating it might take some doing...

The rest should be relatively easy to implement, just a matter of having time. I'll probably implement some of this before finishing the kernel management, which is already turning out to be adding another 20% of code to the total size of the script - from 54kb to 65kb.