tvl-depot/third_party/default.nix
Vincent Ambo 4a89bcd6a5 refactor(ops/nixos): Pass depot as a special argument
This changes the evaluation order for the `depot` argument and ensures
it is partially evaluated before the module system starts resolving
imports.

This way we can import modules from `depot.path` without `depot`
having to come from readTree.

Fixes b/129.

Change-Id: Icf4dd2be15011055dac8b27e991a4ff6a12bf827
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3156
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2021-05-24 21:48:37 +00:00

52 lines
1.7 KiB
Nix

# This file defines the root of all external dependency imports (i.e.
# third-party code) in the TVL package tree.
#
# There are two categories of third-party programs:
#
# 1) Programs in nixpkgs, the NixOS package set. For these, you might
# want to look at //third_party/nixpkgs (for the package set
# imports) and //third_party/overlays (for modifications in these
# imported package sets).
#
# 2) Third-party software packaged in this repository. This is all
# other folders below //third_party, other than the ones mentioned
# above.
{ pkgs, ... }:
{
# Expose a partially applied NixOS, expecting an attribute set with
# a `configuration` key. Exposing it like this makes it possible to
# modify some of the base configuration used by NixOS.
#
# This partially reimplements the code in
# <nixpkgs/nixos/default.nix> as we need to modify its internals to
# be able to pass `specialArgs`. We depend on this because `depot`
# needs to be partially evaluated in NixOS configuration before
# module imports are resolved.
nixos = {
configuration,
specialArgs ? {},
system ? builtins.currentSystem,
...
}:
let
eval = import "${pkgs.path}/nixos/lib/eval-config.nix" {
inherit specialArgs system;
modules = [ configuration ];
};
# This is for `nixos-rebuild build-vm'.
vmConfig = (import "${pkgs.path}/nixos/lib/eval-config.nix" {
inherit specialArgs system;
modules = [
configuration
"${pkgs.path}/nixos/modules/virtualisation/qemu-vm.nix"
];
}).config;
in {
inherit (eval) pkgs config options;
system = eval.config.system.build.toplevel;
vm = vmConfig.system.build.vm;
};
}