home-manager/modules/misc/nix.nix
2022-12-05 12:58:02 +01:00

241 lines
6.9 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.nix;
nixPackage = cfg.package;
isNixAtLeast = versionAtLeast (getVersion nixPackage);
nixConf = assert isNixAtLeast "2.2";
let
mkValueString = v:
if v == null then
""
else if isInt v then
toString v
else if isBool v then
boolToString v
else if isFloat v then
floatToString v
else if isList v then
toString v
else if isDerivation v then
toString v
else if builtins.isPath v then
toString v
else if isString v then
v
else if isCoercibleToString v then
toString v
else
abort "The nix conf value: ${toPretty { } v} can not be encoded";
mkKeyValue = k: v: "${escape [ "=" ] k} = ${mkValueString v}";
mkKeyValuePairs = attrs:
concatStringsSep "\n" (mapAttrsToList mkKeyValue attrs);
in pkgs.writeTextFile {
name = "nix.conf";
text = ''
# WARNING: this file is generated from the nix.settings option in
# your Home Manager configuration at $XDG_CONFIG_HOME/nix/nix.conf.
# Do not edit it!
${mkKeyValuePairs cfg.settings}
${cfg.extraOptions}
'';
checkPhase =
if pkgs.stdenv.hostPlatform != pkgs.stdenv.buildPlatform then ''
echo "Ignoring validation for cross-compilation"
'' else ''
echo "Validating generated nix.conf"
ln -s $out ./nix.conf
set -e
set +o pipefail
NIX_CONF_DIR=$PWD \
${cfg.package}/bin/nix show-config ${
optionalString (isNixAtLeast "2.3pre")
"--no-net --option experimental-features nix-command"
} \
|& sed -e 's/^warning:/error:/' \
| (! grep '${
if cfg.checkConfig then "^error:" else "^error: unknown setting"
}')
set -o pipefail
'';
};
semanticConfType = with types;
let
confAtom = nullOr (oneOf [ bool int float str path package ]) // {
description =
"Nix config atom (null, bool, int, float, str, path or package)";
};
in attrsOf (either confAtom (listOf confAtom));
jsonFormat = pkgs.formats.json { };
in {
options.nix = {
enable = mkEnableOption ''
the Nix configuration module
'' // {
default = true;
visible = false;
};
package = mkOption {
type = types.nullOr types.package;
default = null;
example = literalExpression "pkgs.nix";
description = ''
The Nix package that the configuration should be generated for.
'';
};
registry = mkOption {
type = types.attrsOf (types.submodule (let
inputAttrs = types.attrsOf
(types.oneOf [ types.str types.int types.bool types.package ]);
in { config, name, ... }: {
options = {
from = mkOption {
type = inputAttrs;
example = {
type = "indirect";
id = "nixpkgs";
};
description = "The flake reference to be rewritten.";
};
to = mkOption {
type = inputAttrs;
example = {
type = "github";
owner = "my-org";
repo = "my-nixpkgs";
};
description =
"The flake reference to which <option>from></option> is to be rewritten.";
};
flake = mkOption {
type = types.nullOr types.attrs;
default = null;
example = literalExpression "nixpkgs";
description = ''
The flake input to which <option>from></option> is to be rewritten.
'';
};
exact = mkOption {
type = types.bool;
default = true;
description = ''
Whether the <option>from</option> reference needs to match exactly. If set,
a <option>from</option> reference like <literal>nixpkgs</literal> does not
match with a reference like <literal>nixpkgs/nixos-20.03</literal>.
'';
};
};
config = {
from = mkDefault {
type = "indirect";
id = name;
};
to = mkIf (config.flake != null) ({
type = "path";
path = config.flake.outPath;
} // lib.filterAttrs (n: v:
n == "lastModified" || n == "rev" || n == "revCount" || n
== "narHash") config.flake);
};
}));
default = { };
description = ''
User level flake registry.
'';
};
registryVersion = mkOption {
type = types.int;
default = 2;
internal = true;
description = "The flake registry format version.";
};
checkConfig = mkOption {
type = types.bool;
default = true;
description = ''
If enabled (the default), checks for data type mismatches and that Nix
can parse the generated nix.conf.
'';
};
extraOptions = mkOption {
type = types.lines;
default = "";
example = ''
keep-outputs = true
keep-derivations = true
'';
description =
"Additional text appended to <filename>nix.conf</filename>.";
};
settings = mkOption {
type = types.submodule { freeformType = semanticConfType; };
default = { };
example = literalExpression ''
{
use-sandbox = true;
show-trace = true;
system-features = [ "big-parallel" "kvm" "recursive-nix" ];
}
'';
description = ''
Configuration for Nix, see
<link xlink:href="https://nixos.org/manual/nix/stable/#sec-conf-file"/> or
<citerefentry>
<refentrytitle>nix.conf</refentrytitle>
<manvolnum>5</manvolnum>
</citerefentry> for available options.
The value declared here will be translated directly to the key-value pairs Nix expects.
</para>
<para>
Configuration specified in <option>nix.extraOptions</option> which will be appended
verbatim to the resulting config file.
'';
};
};
config = mkIf cfg.enable {
assertions = [{
assertion = cfg.settings == { } || cfg.package != null;
message = ''
A corresponding Nix package must be specified via `nix.package` for generating
nix.conf.
'';
}];
xdg.configFile = {
"nix/registry.json" = mkIf (cfg.registry != { }) {
source = jsonFormat.generate "registry.json" {
version = cfg.registryVersion;
flakes =
mapAttrsToList (n: v: { inherit (v) from to exact; }) cfg.registry;
};
};
"nix/nix.conf" = mkIf (cfg.settings != { } || cfg.extraOptions != "") {
source = nixConf;
};
};
};
meta.maintainers = [ maintainers.polykernel ];
}