stockholm/krebs/3modules/power-action.nix
2019-10-14 13:11:56 +02:00

92 lines
2.1 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.krebs.power-action;
out = {
options.krebs.power-action = api;
config = lib.mkIf cfg.enable imp;
};
api = {
enable = mkEnableOption "power-action";
battery = mkOption {
type = types.str;
default = "BAT0";
};
user = mkOption {
type = types.str;
default = "power-action";
};
startAt = mkOption {
type = types.str;
default = "*:0/1";
};
plans = mkOption {
type = with types; attrsOf (submodule {
options = {
charging = mkOption {
type = nullOr bool;
default = null;
description = ''
check for charging status.
null = don't care
true = only if system is charging or unknown
false = only if system is discharging
'';
};
upperLimit = mkOption {
type = int;
};
lowerLimit = mkOption {
type = int;
};
action = mkOption {
type = path;
};
};
});
};
};
imp = {
systemd.services.power-action = {
serviceConfig = rec {
ExecStart = startScript;
User = cfg.user;
};
startAt = cfg.startAt;
};
};
startScript = pkgs.writeDash "power-action" ''
set -euf
power="$(${powerlvl})"
state="$(${state})"
${concatStringsSep "\n" (mapAttrsToList writeRule cfg.plans)}
'';
charging_check = plan:
if (plan.charging == null) then "" else
if plan.charging
then ''&& [ "$state" = "true" ]''
else ''&& ! [ "$state" = "true" ]''
;
writeRule = _: plan:
"if [ $power -ge ${toString plan.lowerLimit} ] && [ $power -le ${toString plan.upperLimit} ] ${charging_check plan}; then ${plan.action}; fi";
powerlvl = pkgs.writeDash "powerlvl" ''
cat /sys/class/power_supply/${cfg.battery}/capacity
'';
state = pkgs.writeDash "state" ''
if [ "$(cat /sys/class/power_supply/${cfg.battery}/status)" = "Discharging" ]
then echo "false"
else echo "true"
fi
'';
in out