gistfile1.txt

{ config, pkgs, lib, ... } @ args:

#with lib;

let
  stateDir = "/var/lib/crawler/";

in
{
  users = {
    users.crawler= {
      #note this is a hack since this is not commited to the nixpkgs
      uid             = 2147483647;
      description     = "crawler server user";
      group           = "crawler";
      home            = stateDir;
      createHome      = true;
    };

    groups.crawler= {
      #note this is a hack since this is not commited to the nixpkgs
      gid = 2147483648;
    };
  };

  systemd.services.crawler= {
    script = ''
        ${stateDir}/collect_data.py > ${stateDir}/data.json
      '';
        #${dbInserter} ${stateDir}/data.json
    serviceConfig = {
      Nice = 19;
      IOSchedulingClass = "idle";
      PrivateTmp = "yes";
      PrivateNetwork = "yes";
      NoNewPrivileges = "yes";
      ReadOnlyDirectories = "/";
      ReadWriteDirectories = stateDir;
      WorkingDirectory = stateDir;
    };
  };

  systemd.timers.crawler = { 
    description = "crawler service";
    partOf      = [ "crawler.service" ];
    wantedBy    = [ "timers.target" ];
    timerConfig.OnCalendar = "10min";
  };
}

[root@nixcloud:/etc/nixos]# systemctl list-timers --all
NEXT                          LEFT          LAST                          PASSED  UNIT                         ACTIVATES
Mon 2016-10-24 21:53:38 CEST  3h 31min left Sun 2016-10-23 21:53:38 CEST  20h ago systemd-tmpfiles-clean.timer systemd-tmpf
Mon 2016-10-31 00:00:00 CET   6 days left   Mon 2016-10-24 00:00:03 CEST  18h ago acme-drschiele.de.timer      acme-drschie
Mon 2016-10-31 00:00:00 CET   6 days left   Mon 2016-10-24 00:00:03 CEST  18h ago acme-dune2.de.timer          acme-dune2.d
Mon 2016-10-31 00:00:00 CET   6 days left   Mon 2016-10-24 00:00:03 CEST  18h ago acme-lastlog.de.timer        acme-lastlog
Mon 2016-10-31 00:00:00 CET   6 days left   Mon 2016-10-24 00:00:03 CEST  18h ago acme-nixcloud.io.timer       acme-nixclou
n/a                           n/a           n/a                           n/a     crawler.timer                crawler.serv