{ config, pkgs, ... }: with pkgs.lib; let cfg = config.nix.gc; in { ###### interface options = { nix.gc = { automatic = mkOption { default = false; type = types.bool; description = "Automatically run the garbage collector at a specific time."; }; dates = mkOption { default = "00:43"; type = types.uniq types.string; description = '' Specification (in the format described by systemd.time 5) of the time at which the garbage collector will run. ''; }; options = mkOption { default = ""; example = "--max-freed $((64 * 1024**3))"; type = types.uniq types.string; description = '' Options given to nix-collect-garbage when the garbage collector is run automatically. ''; }; }; }; ###### implementation config = { #systemd.timers.nix-gc.enable = cfg.automatic; systemd.timers.nix-gc.enable = true; systemd.timers.nix-gc.timerConfig.OnCalendar = cfg.dates; systemd.services.nix-gc = { description = "Nix Garbage Collector"; path = [ config.environment.nix ]; script = "exec nix-collect-garbage ${cfg.options}"; }; }; }