nixpkgs/nixos/tests/systemd-misc.nix

{ pkgs, ... }:

let
  exampleScript = pkgs.writeTextFile {
    name = "example.sh";
    text = ''
      #! ${pkgs.runtimeShell} -e

      while true; do
          echo "Example script running" >&2
          ${pkgs.coreutils}/bin/sleep 1
      done
    '';
    executable = true;
  };

  unitFile = pkgs.writeTextFile {
    name = "example.service";
    text = ''
      [Unit]
      Description=Example systemd service unit file

      [Service]
      ExecStart=${exampleScript}

      [Install]
      WantedBy=multi-user.target
    '';
  };
in
{
  name = "systemd-misc";

  nodes.machine =
    { pkgs, lib, ... }:
    {
      boot.extraSystemdUnitPaths = [ "/etc/systemd-rw/system" ];

      users.users.limited = {
        isNormalUser = true;
        uid = 1000;
      };

      systemd.units."user-1000.slice.d/limits.conf" = {
        text = ''
          [Slice]
          TasksAccounting=yes
          TasksMax=100
        '';
      };
    };

  testScript = ''
    machine.wait_for_unit("multi-user.target")
    machine.succeed("mkdir -p /etc/systemd-rw/system")
    machine.succeed(
        "cp ${unitFile} /etc/systemd-rw/system/example.service"
    )
    machine.succeed("systemctl start example.service")
    machine.succeed("systemctl status example.service | grep 'Active: active'")

    machine.succeed("systemctl show --property TasksMax --value user-1000.slice | grep 100")
  '';
}