Properly stop process started with sudo

[isamert]

Prodigy can't stop processes started with sudo because it does not
have the privileges to do that. This PR simply fixes that by running
the kill command with prodigy-start-sudo-process and with given
stop-signal. Partially fixes #111.

[Fuco1]

Maybe a different approach would be to set default directory using TRAMP and sudo protocol and then call the original code. I would as much as possible try to use the stop-process and similar Emacs commands instead of using utilities such as pgrep which aren't necessarily very portable.

[isamert]

While writing a response I figured out a way to not depending on pgrep, turns out sending the signal with appending - before the process group id redirects the signal to all children, which greatly simplified the implementation.

I agree that utilizing TRAMP would be the best possible solution but there are a few blockers:

• Current :sudo t depends on calling sudo itself directly, so we need a whole refactor here to make it work with TRAMP.
• Signalling the process directly does not work, because sudo creates a process group and sending a signal to this group is not passed to the children (I don't know why though, this is something about how sudo works). We still need to figure out what the child process id's are and signal them or we will use kill with the - trick again (but at least kill is more portable?).

Currently killing services with :sudo t does not work at all, this PR at least fixes that. With the latest change, it's even simpler.

[Fuco1]

Sounds good to me. Plus if it fixes the issue for at least some portion of the users that's a good change for me. It seems to be backward compatible with the non-sude tasks.

We can think about the refactor later, but I think there is already enough value to merge this. Thanks for looking into it!

[Fuco1]

Apparently this repo requires all commits to be signed:

Is this an option for you? If not, I can rebase them somehow so they get signed (it should still retain you as the author though, I don't want to take the credit)

This is the link: https://docs.github.com/en/authentication/managing-commit-signature-verification/about-commit-signature-verification

[isamert]

Sorry for getting back late, thanks for the heads up. Signed the commits and updated.

[isamert]

@Fuco1 just a nudge to remind you about this.

[DamienCassou]

@isamert Could you please squash your 2 commits into 1? I can do it if you prefer.

[isamert]

You can squash if it's okay for you, thanks!

[DamienCassou]

Done. Thank you very much for your work.