nixpkgs/nixos/modules/config/nix-flakes.nix
r-vdp 1d160e9cc1
Remove the revCount attribute from the generated flake registry
The revCount attribute is only present when the flake is an actual git
repo and not when using a flake reference with an input scheme for a git
forge that downloads tarballs instead (like github: or sourcehut:).
Because of this, the hash of the nixos config changes depending on
whether the config was built from a local git clone or from a flake ref
using one of those input schemes.
This leads to confusion (I lost quite some time figuring out what
happened here) and unnecessary rebuilds.
To my knowledge, there is no immediate benefit to including revCount in
the flake registry entry.
2024-05-31 20:31:41 +02:00

96 lines
2.5 KiB
Nix

/*
Manages the flake registry.
See also
- ./nix.nix
- ./nix-channel.nix
*/
{ config, lib, ... }:
let
inherit (lib)
filterAttrs
literalExpression
mapAttrsToList
mkDefault
mkIf
mkOption
types
;
cfg = config.nix;
in
{
options = {
nix = {
registry = mkOption {
type = types.attrsOf (types.submodule (
let
referenceAttrs = with types; attrsOf (oneOf [
str
int
bool
path
package
]);
in
{ config, name, ... }:
{
options = {
from = mkOption {
type = referenceAttrs;
example = { type = "indirect"; id = "nixpkgs"; };
description = "The flake reference to be rewritten.";
};
to = mkOption {
type = referenceAttrs;
example = { type = "github"; owner = "my-org"; repo = "my-nixpkgs"; };
description = "The flake reference {option}`from` is rewritten to.";
};
flake = mkOption {
type = types.nullOr types.attrs;
default = null;
example = literalExpression "nixpkgs";
description = ''
The flake input {option}`from` is rewritten to.
'';
};
exact = mkOption {
type = types.bool;
default = true;
description = ''
Whether the {option}`from` reference needs to match exactly. If set,
a {option}`from` reference like `nixpkgs` does not
match with a reference like `nixpkgs/nixos-20.03`.
'';
};
};
config = {
from = mkDefault { type = "indirect"; id = name; };
to = mkIf (config.flake != null) (mkDefault (
{
type = "path";
path = config.flake.outPath;
} // filterAttrs
(n: _: n == "lastModified" || n == "rev" || n == "narHash")
config.flake
));
};
}
));
default = { };
description = ''
A system-wide flake registry.
'';
};
};
};
config = mkIf cfg.enable {
environment.etc."nix/registry.json".text = builtins.toJSON {
version = 2;
flakes = mapAttrsToList (n: v: { inherit (v) from to exact; }) cfg.registry;
};
};
}