nixnew/modules/impurity.nix

44 lines
1.4 KiB
Nix

self: { lib, config, pkgs, ... }: with lib; let
relativePath = path: assert types.path.check path;
with builtins; strings.removePrefix (toString self) (toString path);
impurityGroupEnabled = group: let
impurityGroups = strings.splitString " " (builtins.getEnv "IMPURITY_GROUPS");
in group == "" || builtins.elem group impurityGroups;
impurePath = let
impurePathEnv = builtins.getEnv "IMPURITY_PATH";
in if impurePathEnv == ""
then throw "impurity.enable is true but IMPURITY_PATH is not set"
else impurePathEnv;
createImpurePath = path: let
relative = (relativePath path);
full = impurePath + relative;
in pkgs.runCommand "impurity-${relative}" {} "ln -s ${full} $out";
in {
options.impurity.enable = mkOption {
type = types.bool;
default = false;
description = "Enable impure symlinks";
};
config._module.args.impurity = rec {
groupedLink = groupspec: path:
assert types.path.check path; let
groups =
if groupspec == null
then [ "" ]
else if (types.listOf types.string).check groupspec
then groupspec
else assert types.string.check groupspec;
strings.splitString " " groupspec;
in if config.impurity.enable && lists.any (group: impurityGroupEnabled group) groups
then createImpurePath path
else path;
link = path: groupedLink null path;
};
}