nixpkgs/nixos/modules/misc/assertions.nix
Silvan Mosberger 8dea4df903
lib/modules: Remove _module.checks.*.triggerPath as it's not necessary
Previously this option was thought to be necessary to avoid infinite
recursion, but it actually isn't, since the check evaluation isn't fed
back into the module fixed-point.
2020-11-30 23:51:42 +01:00

48 lines
1.3 KiB
Nix

{ lib, config, ... }:
with lib;
{
options = {
assertions = mkOption {
type = types.listOf types.unspecified;
internal = true;
default = [];
example = [ { assertion = false; message = "you can't enable this for that reason"; } ];
description = ''
This option allows modules to express conditions that must
hold for the evaluation of the system configuration to
succeed, along with associated error messages for the user.
'';
};
warnings = mkOption {
internal = true;
default = [];
type = types.listOf types.str;
example = [ "The `foo' service is deprecated and will go away soon!" ];
description = ''
This option allows modules to show warnings to users during
the evaluation of the system configuration.
'';
};
};
config._module.checks = lib.listToAttrs (lib.imap1 (n: value:
let
name = "_${toString n}";
isWarning = lib.isString value;
result = {
enable = if isWarning then true else ! value.assertion;
type = if isWarning then "warning" else "error";
message = if isWarning then value else value.message;
};
in nameValuePair name result
) (config.assertions ++ config.warnings));
# impl of assertions is in <nixpkgs/nixos/modules/system/activation/top-level.nix>
}