nixos/jellyfin: add directory options

[fsnkty]

Description of changes

add dataDir configDir cacheDir and logDir options

ideally a lot of config and data dirs would be declared in some way, but the ability to easily define their locations is nicer than nothing.
the webdir option explained here is as far as i know not relevant given its in the store.

this should replace PR #233617 ( I've tried to address the unresolved comments here )
it should also close #141367 as a result.

removed with lib; to address #208242 for this module.

add meta.mainProgram to the jellyfin server package so that getExe can be used appropriately.

remove use of the now pointless lib.mdDoc

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.

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[fsnkty]

Welp I struggled with that more than I'd like to have been shown lol. Lesson learnt, test locally always 😵‍💫

also TIL you can merge suggestions right from within GitHubs website.

unrelated question, can you preserve the commit messages of commits which must be squashed? the last few force pushes now feel silly without any immediate context.

[fsnkty]

somewhere in this process I've managed to break the service.

Jan 03 16:16:44 library (jellyfin)[24592]: jellyfin.service: Changing to the requested working directory failed: Permission denied
Jan 03 16:16:44 library (jellyfin)[24592]: jellyfin.service: Failed at step CHDIR spawning /nix/store/0d8ji5b45v59n7179pvg8a4ci7044qj7-jellyfin-10.8.13/bin/jellyfin: Permission denied

persists when state is removed and is a problem with another user trying to use this PR. this was working before my first push today.

[fsnkty]

somewhere in this process I've managed to break the service.

Jan 03 16:16:44 library (jellyfin)[24592]: jellyfin.service: Changing to the requested working directory failed: Permission denied
Jan 03 16:16:44 library (jellyfin)[24592]: jellyfin.service: Failed at step CHDIR spawning /nix/store/0d8ji5b45v59n7179pvg8a4ci7044qj7-jellyfin-10.8.13/bin/jellyfin: Permission denied

persists when state is removed and is a problem with another user trying to use this PR. this was working before my first push today.

removing the workingDir line moves the issue to some permissions faults with the log directory.
I've attempted to set the permissions to 770 and the umask of the service to 0770 to no avail.

converting to a draft till I can find the issue here, any insight is greatly appreciated.

[fsnkty]

In that latest force-push I removed privateUsers = true something I'm not super confident about.
my reasoning is that it was the only option that would cause the services permission errors to read from directorys within the base dir, such as log and config. even with 770 permissions applied.
I'd appreciate insight on the potential consequences of this if any as this resource didn't help me understand much.

I also added more links to jellyfin documentation using some markdown after finding out that was available.
I'll have one more force push to cleanup a formatting mistake I left in from testing and then I'll move the PR out of a draft again.

[nixos-discourse]

This pull request has been mentioned on NixOS Discourse. There might be relevant details there:

https://discourse.nixos.org/t/prs-ready-for-review/3032/3264

[nevivurn]

PrivateUsers makes other users (not root or jellyfin) invisible to this unit. Jellyfin should work with it enabled, so this is a (minor) regression and should be fixed, imo.

[nevivurn]

Looks great

[fsnkty]

given the PR this replaces had some users preemptively using the changes I'll leave this here as reference for how I've been testing / making use of the changes myself.

small update to this, cant recommend using the jellyfin(package) ver from this on unstable since some changes have borked hw transcodes with it, will be fine once merged of course.

[fsnkty]

latest force push was simply to ensure exact permissions lineup with whats current.
previous was non problematic but also uselessly open for the group with 750, corrected to 700
( there must be a better way to comment on this stuff with the github ui)

[NotAShelf]

I thought using mdDoc was a no-op as documentation now uses markdown by default?

[eclairevoyant]

I thought using mdDoc was a no-op as documentation now uses markdown by default?

Correct, since d36f950 (#237557) which was merged in June 2023:

nixpkgs/lib/options.nix

Lines 384 to 387 in 0a25418

	/* Transition marker for documentation that's already migrated to markdown
	syntax. This is a no-op and no longer needed.
	*/
	mdDoc = lib.id;

Any uses of mdDoc can be removed.

[drupol]

LGTM

[NotAShelf]

LGTM