Suspend and then hibernate after 60 minutes

README.markdown

I found a post about suspending and then going into hibernate that included a really clever script. Turns out that with NixOS this is even esaier to coordinate as you have systemd so can have a before and after service. I just include this in my /etc/nixos/configuration.nix file and nixos-rebuild; then a systemctl suspend or a close of the lid will cause the hibernate timer to be set.

suspend-and-hibernate.nix

{ config, pkgs, ... }: let
  hibernateEnvironment = {
    HIBERNATE_SECONDS = "3600";
    HIBERNATE_LOCK = "/var/run/autohibernate.lock";
  };
in {
  systemd.services."awake-after-suspend-for-a-time" = {
    description = "Sets up the suspend so that it'll wake for hibernation";
    wantedBy = [ "suspend.target" ];
    before = [ "systemd-suspend.service" ];
    environment = hibernateEnvironment;
    script = ''
      curtime=$(date +%s)
      echo "$curtime $1" >> /tmp/autohibernate.log
      echo "$curtime" > $HIBERNATE_LOCK
      ${pkgs.utillinux}/bin/rtcwake -m no -s $HIBERNATE_SECONDS
    '';
    serviceConfig.Type = "simple";
  };
  systemd.services."hibernate-after-recovery" = {
    description = "Hibernates after a suspend recovery due to timeout";
    wantedBy = [ "suspend.target" ];
    after = [ "systemd-suspend.service" ];
    environment = hibernateEnvironment;
    script = ''
      curtime=$(date +%s)
      sustime=$(cat $HIBERNATE_LOCK)
      rm $HIBERNATE_LOCK
      if [ $(($curtime - $sustime)) -ge $HIBERNATE_SECONDS ] ; then
        systemctl hibernate
      else
        ${pkgs.utillinux}/bin/rtcwake -m no -s 1
      fi
    '';
    serviceConfig.Type = "simple";
  };
}

To fill in all the background to what I found out, it was specifically fixed in Systemd v253 (released February 15, 2023 but depends on when your distro updated to it).

        * systemd-sleep 'HibernateDelaySec=' setting is changed back to
          pre-v252's behaviour, and a new 'SuspendEstimationSec=' setting is
          added to provide the new initial value for the new automated battery
          estimation functionality. If 'HibernateDelaySec=' is set to any value,
          the automated estimate (and thus the automated hibernation on low
          battery to avoid data loss) functionality will be disabled.

Release page: https://github.com/systemd/systemd/releases/tag/v253

There are a couple more lid options in NixOS:
https://search.nixos.org/options?channel=24.05&from=0&size=50&sort=relevance&type=packages&query=services.logind.lidSwitch

services.logind.lidSwitchExternalPower defaults to what is set for services.logind.lidSwitch so I’m fine with this setting.

services.logind.lidSwitchDocked defaults to ignore which I like as well since I’m often docked to an external monitor so this means I can put the lid down and it doesn’t Suspend.

Has anyone figured out how to get this to work without that awesome before an after script? Its so weird that setting a simple 'suspend-then-hibernate' still won't work on NixOS.

Has anyone figured out how to get this to work without that awesome before an after script? Its so weird that setting a simple 'suspend-then-hibernate' still won't work on NixOS.

Read my 2 replies above. Suspend-then-hibernate works.

@jyap808 thanks a lot for the details :)