nixpkgs-suyu/nixos/modules/config/system-environment.nix
2014-06-10 13:07:10 +02:00

56 lines
1.6 KiB
Nix

# This module defines a system-wide environment that will be
# initialised by pam_env (that is, not only in shells).
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.environment;
in
{
options = {
environment.systemVariables = mkOption {
default = {};
description = ''
A set of environment variables used in the global environment.
These variables will be set by PAM.
The value of each variable can be either a string or a list of
strings. The latter is concatenated, interspersed with colon
characters.
'';
type = types.attrsOf (mkOptionType {
name = "a string or a list of strings";
merge = loc: defs:
let
defs' = filterOverrides defs;
res = (head defs').value;
in
if isList res then concatLists (getValues defs')
else if lessThan 1 (length defs') then
throw "The option `${showOption loc}' is defined multiple times, in ${showFiles (getFiles defs)}."
else if !isString res then
throw "The option `${showOption loc}' does not have a string value, in ${showFiles (getFiles defs)}."
else res;
});
apply = mapAttrs (n: v: if isList v then concatStringsSep ":" v else v);
};
};
config = {
system.build.pamEnvironment = pkgs.writeText "pam-environment"
''
${concatStringsSep "\n" (
(mapAttrsToList (n: v: ''${n}="${concatStringsSep ":" v}"'')
(zipAttrsWith (const concatLists) ([ (mapAttrs (n: v: [ v ]) cfg.systemVariables) ]))))}
'';
};
}