dae: add support for geolocation databases

[1sixth]

Description of changes

also installs a systemd service

Things done

• Built on platform(s)
  • x86_64-linux
  • aarch64-linux
  • x86_64-darwin
  • aarch64-darwin
• For non-Linux: Is sandbox = true set in nix.conf? (See Nix manual)
• 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/)
• 23.11 Release Notes (or backporting 23.05 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.

[oluceps]

I recommend adding a NixOS module as an alternative or making some modifications to the upstream unit files. Here are the reasons:

dae relies on a geolocation database at runtime. If it cannot be found in hardcoded absoluted path or xdg data dir (May not exist?) it fails to start. This may be hard to handle if install the service directly. See https://github.com/daeuniverse/dae/blob/242bc19e4a8e4d052cb45ab37b76dc556ce692fe/common/assets/assets.go#L71 and #81138.

[1sixth]

I've updated the code to let dae use geolocation databases. It's mostly copied from v2ray/default.nix, but I didn't add support to override assets because of the way dae searches assets:

1. If DAE_LOCATION_ASSET is set, dae expects them to be in that directory, it won't search sub-directories.
2. If XDG_DATA_DIRS is set, dae expects them to be in $XDG_DATA_DIRS/dae.

I can't really find a nice way to make dae use other databases like sing-geoip.

[oluceps]

I can't really find a nice way to make dae use other databases like sing-geoip.

sing-geoip isn't compatible with dae. It doesn't matter.

Considering nixpkgs is also for non-NixOS systems, is the unit file work in that case?

Maybe adding a nixos module instead is a better choice.

[1sixth]

is the unit file work in that case?

probably not, see https://discourse.nixos.org/t/how-to-start-systemd-services-provided-by-packages-installed-through-nix-on-an-alien-distro/23056

Maybe adding a nixos module instead is a better choice.

I agree that a nixos module is better. But it doesn't conflict with shipping a systemd service. For example, the v2ray module and the sing-box module both use the systemd service from upstream:

nixpkgs/nixos/modules/services/networking/v2ray.nix

Line 88 in dfcc258

systemd.packages = [ cfg.package ];

nixpkgs/nixos/modules/services/networking/sing-box.nix

Line 55 in dfcc258

systemd.packages = [ cfg.package ];

[oluceps]

Perhaps both the installation of the service and the steps in postFixup can be moved to the postInstall phase to avoid modifying the installPhase. Apart from that, it looks good to me.

[oluceps]

Result of nixpkgs-review pr 244129 run on x86_64-linux 1

1 package built:

• dae

[NickCao]

Isn't this line redundant? (the binary should already be installed in the installPhase)