nixpkgs/nixos/modules/services/misc/nix-optimise.nix
2022-03-21 23:14:10 +01:00

57 lines
1.3 KiB
Nix

{ config, lib, ... }:
with lib;
let
cfg = config.nix.optimise;
in
{
###### interface
options = {
nix.optimise = {
automatic = mkOption {
default = false;
type = types.bool;
description = "Automatically run the nix store optimiser at a specific time.";
};
dates = mkOption {
default = ["03:45"];
type = types.listOf types.str;
description = ''
Specification (in the format described by
<citerefentry><refentrytitle>systemd.time</refentrytitle>
<manvolnum>7</manvolnum></citerefentry>) of the time at
which the optimiser will run.
'';
};
};
};
###### implementation
config = {
assertions = [
{
assertion = cfg.automatic -> config.nix.enable;
message = ''nix.optimise.automatic requires nix.enable'';
}
];
systemd.services.nix-optimise = lib.mkIf config.nix.enable
{ description = "Nix Store Optimiser";
# No point this if the nix daemon (and thus the nix store) is outside
unitConfig.ConditionPathIsReadWrite = "/nix/var/nix/daemon-socket";
serviceConfig.ExecStart = "${config.nix.package}/bin/nix-store --optimise";
startAt = optionals cfg.automatic cfg.dates;
};
};
}