thelounge: Set THELOUNGE_HOME environment variable

[nuxeh]

Setting this environment variable allows the CLI to correctly locate the
state directory, allowing users to be added, etc. from the command line,
without additionally having to set this variable.

Motivation for this change

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nix-review --run "nix-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

Notify maintainers

cc @Mrmaxmeier

[flokli]

Hmm, I wouldn't suggest to set this environment variable globally.

Instead, we might want to patch the CLI to use the used state directory location as a default. Reading its function definition, this could be accomplished by adding a

echo /var/lib/thelounge > $out/lib/node_modules/thelounge/.thelounge_home

to the thelounge postInstall in pkgs/development/node-packages/default-v10.nix.

[Ekleog]

@nuxeh Are you still interested in moving this forward, with @flokli's comments? :)

[nuxeh]

At the time I was somewhat doubtful of my own aptitude for implementing or testing it, I personally haven't written a line of Javascript in a long time.

Also it's my instinct that this solution is slightly more error-prone (especially going forwards, it may need to be maintained) than simply setting an environment variable, which doesn't seem to be too much of an issue? It'll only be present when the lounge is installed after all, and is fairly well namespaced as THELOUNGE_HOME. I don't really know the conventions of Nix for this sort of thing, however.

It is something that would be nice to have a fix for, certainly. I could look at it at some point.

[nuxeh]

Haha, oh wait, I wasn't paying enough attention... the suggestion isn't to patch the Javascript at all.

[nuxeh]

@Ekleog just done this, seems to work nicely!

[Ekleog]

Great! That said, I've just looked at the current state of this PR, and it looks to me like you could revert the changes in nixos/modules/services/networking/thelounge.nix now that the correct path is being set right into the CLI tools :)

[nuxeh]

Oh, right, yes, I totally forgot!