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";
  };
}

this is awesome! suspend-then-hibernate from systemd was first broken by a weird spat between the maintainer and everyone else, then kinda stopped working entirely for me. This config works, with one minor addition you might want to add at some point -- if you have an nvidia card and use the power management systemd services, then hibernate-after-recovery should come after "nvidia-resume.service".

I tested it on my nixos setup and works as intended. Many thanks 😁. Was curious as to why before it goes to hibernation it needs to wake up first from suspend.