nixos/mautrix-discord: init

[robintown]

Description of changes

mautrix-discord has already been packaged, but as of yet no NixOS module has been provided. This is the same module that I've revived from #200462, but now with expanded hardening.

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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[raspher]

Result of nixpkgs-review pr 284421 run on aarch64-linux 1

1 package blacklisted:

• nixos-install-tools

[fsnkty]

Looks good to me, thanks!

[robintown]

@azahi / @rrix, might one of you be willing to give this another review given your interest in #200462?

[azahi]

You forgot to add the test file to nixos/tests/all-tests.nix. Other than that, LGTM.

[Rutherther]

Hello, I have a few notes,

1. It seems that there is mkIf cfg.enable twice in the code, that looks unnecessary to me.

2. Notice for example the mautrix whatsapp bridge service copies the config first to data dir via envsubst. This allows to pass in secrets via the environment file. That can be useful for the login shared secrets etc. Also thanks to it being before registration generation you can pass something else to the config for generation of registration. The way its in this service it looks like this won't be possible.

3. Also, would it make sense to make the dataDir configurable?

[Rutherther]

I have recently Made pr with mautrix-meta service that has data dir configurable, so you can take a look. #296718

[Jo-Blade]

Hello ! Is there anything new about this module ? Can I use it safely on my homeserver ?
Do you need some help to fix issues otherwise ?