nixos/gnome-remote-desktop: add package to environment.systemPackages…

[Nanotwerp]

…, services.dbus.packages, create gnome-remote-desktop user and group (fixes for GNOME 46)

This adds the g-r-d package to environment.systemPackages (allowing the usage of the grdctl command along with enabling g-r-d's polkit rule), makes its dbus-related files recognizable to dbus, and creates the gnome-remote-desktop user and group necessary for systemd's running of the gnome-remote-desktop-daemon with the --system subcommand and enabling Remote Login.

Description of changes

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandboxing enabled in nix.conf? (See Nix manual)
  • sandbox = relaxed
  • sandbox = true
• Tested, as applicable:
  • NixOS test(s) (look inside nixos/tests)
  • and/or package tests
  • or, for functions and "core" functionality, tests in lib/tests or pkgs/test
  • made sure NixOS tests are linked to the relevant packages
• Tested compilation of all packages that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review rev HEAD". Note: all changes have to be committed, also see nixpkgs-review usage
• Tested basic functionality of all binary files (usually in ./result/bin/)
• 24.05 Release Notes (or backporting 23.05 and 23.11 Release notes)
  • (Package updates) Added a release notes entry if the change is major or breaking
  • (Module updates) Added a release notes entry if the change is significant
  • (Module addition) Added a release notes entry if adding a new NixOS module
• Fits CONTRIBUTING.md.

---

Add a 👍 reaction to pull requests you find important.

[jtojnar]

Hmm, I thought it would be automatically set up but looks like it is still experimental in NixOS and disabled by default:

nixpkgs/nixos/modules/system/boot/systemd/sysusers.nix

Line 75 in 383dbce

Note: This is experimental.

[Nanotwerp]

Ooh, I didn't even know that NixOS even had that feature! Would you recommend that I swap out the manual user and group creation for systemd.sysusers.enable = true?

EDIT: Absolutely nevermind. I just experienced the scariest thing known to man after enabling systemd.sysusers while having mutableUsers disabled. All of my users were rendered useless and I couldn't login to any of them. Thank every god known to mankind for Nix generations. I should've listened when I heard it was experimental.

[amaxine]

Should user creation be conditional based on sysusers being enabled? Do we do that anywhere right now - and should we? Afaict we only have a comment next to flatpak to switch to sysusers at some point when possible.

[jtojnar]

Would you recommend that I swap out the manual user and group creation for systemd.sysusers.enable = true?

Yeah, that could have unintended side-effects, as you found out. Stuff like this is usually better enabled top-down, rather than bottom up.

Should user creation be conditional based on sysusers being enabled? Do we do that anywhere right now - and should we?

Not sure how it behaves when there are conflicts between sysusers and users.users. It might be a good idea to test it for future-proofing once the sysusers.nix functionality is enabled but not critical at the moment.

[jtojnar]

Actually, looking at the sysuser.nix that just makes it so users.users users are created using sysusers.d – the systemd functionality should already be enabled.

[amaxine]

I don't think that has any effect beyond being built with necessary support, same as homed support always being compiled in but not on by default - but I'd prefer if maybe someone who maintains systemd in nix could weigh in.

Maybe for now it's enough to just add a comment in the module saying that the package provides a sysusers.d file we should switch to one day.

[amaxine]

Looks good, thanks for taking a look at this and getting things working.