tvl-depot/ops/nixos.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
1.4 KiB
Nix

# Helper functions for instantiating depot-compatible NixOS machines.
{ depot, lib, pkgs, ... }@args:
let inherit (lib) findFirst isAttrs;
in rec {
# This provides our standard set of arguments to all NixOS modules.
baseModule = { ... }: {
# Ensure that pkgs == third_party.nix
nixpkgs.pkgs = depot.third_party.nixpkgs;
nix.nixPath = [
"nixos=${pkgs.path}"
"nixpkgs=${pkgs.path}"
];
};
nixosFor = configuration: (depot.third_party.nixos {
configuration = { ... }: {
imports = [
baseModule
configuration
];
};
specialArgs = {
inherit (args) depot;
};
});
findSystem = hostname:
(findFirst
(system: system.config.networking.hostName == hostname)
(throw "${hostname} is not a known NixOS host")
(map nixosFor depot.ops.machines.all-systems));
rebuild-system = pkgs.writeShellScriptBin "rebuild-system" ''
set -ue
if [[ $EUID -ne 0 ]]; then
echo "Oh no! Only root is allowed to rebuild the system!" >&2
exit 1
fi
echo "Rebuilding NixOS for $HOSTNAME"
system=$(nix-build -E "((import ${toString depot.path} {}).ops.nixos.findSystem \"$HOSTNAME\").system" --no-out-link --show-trace)
nix-env -p /nix/var/nix/profiles/system --set $system
$system/bin/switch-to-configuration switch
'';
# Systems that should be built in CI
whitbySystem = (nixosFor depot.ops.machines.whitby).system;
meta.targets = [ "whitbySystem" ];
}