nixpkgs/nixos/modules/services/networking/supybot.nix

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

with lib;

let
  cfg  = config.services.supybot;
  isStateDirHome = hasPrefix "/home/" cfg.stateDir;
  isStateDirVar = cfg.stateDir == "/var/lib/supybot";
in
{
  options = {

    services.supybot = {

      enable = mkOption {
        default = false;
        description = "Enable Supybot, an IRC bot";
      };

      stateDir = mkOption {
        type = types.path;
        default = if versionAtLeast config.system.stateVersion "20.09"
          then "/var/lib/supybot"
          else "/home/supybot";
        defaultText = "/var/lib/supybot";
        description = "The root directory, logs and plugins are stored here";
      };

      configFile = mkOption {
        type = types.path;
        description = ''
          Path to initial supybot config file. This can be generated by
          running supybot-wizard.

          Note: all paths should include the full path to the stateDir
          directory (backup conf data logs logs/plugins plugins tmp web).
        '';
      };

    };

  };

  config = mkIf cfg.enable {

    environment.systemPackages = [ pkgs.pythonPackages.limnoria ];

    users.users.supybot = {
      uid = config.ids.uids.supybot;
      group = "supybot";
      description = "Supybot IRC bot user";
      home = cfg.stateDir;
      isSystemUser = true;
    };

    users.groups.supybot = {
      gid = config.ids.gids.supybot;
    };

    systemd.services.supybot = {
      description = "Supybot, an IRC bot";
      after = [ "network.target" ];
      wantedBy = [ "multi-user.target" ];
      path = [ pkgs.pythonPackages.limnoria ];
      preStart = ''
        # This needs to be created afresh every time
        rm -f '${cfg.stateDir}/supybot.cfg.bak'
      '';

      serviceConfig = {
        ExecStart = "${pkgs.pythonPackages.limnoria}/bin/supybot ${cfg.stateDir}/supybot.cfg";
        PIDFile = "/run/supybot.pid";
        User = "supybot";
        Group = "supybot";
        UMask = "0007";
        Restart = "on-abort";
        StartLimitInterval = "5m";
        StartLimitBurst = "1";

        NoNewPrivileges = true;
        PrivateDevices = true;
        PrivateMounts = true;
        PrivateTmp = true;
        ProtectControlGroups = true;
        ProtectKernelModules = true;
        ProtectKernelTunables = true;
        RestrictAddressFamilies = [ "AF_INET" "AF_INET6" ];
        RestrictSUIDSGID = true;
        SystemCallArchitectures = "native";
        RestrictNamespaces = true;
        RestrictRealtime = true;
        LockPersonality = true;
        MemoryDenyWriteExecute = true;
        RemoveIPC = true;
        ProtectHostname = true;
        CapabilityBoundingSet = "";
        ProtectSystem = "full";
      }
      // optionalAttrs isStateDirVar {
        StateDirectory = "supybot";
        ProtectSystem = "strict";
      }
      // optionalAttrs (!isStateDirHome) {
        ProtectHome = true;
      };
    };

    systemd.tmpfiles.rules = [
      "d '${cfg.stateDir}'              0700 supybot supybot - -"
      "d '${cfg.stateDir}/backup'       0750 supybot supybot - -"
      "d '${cfg.stateDir}/conf'         0750 supybot supybot - -"
      "d '${cfg.stateDir}/data'         0750 supybot supybot - -"
      "d '${cfg.stateDir}/plugins'      0750 supybot supybot - -"
      "d '${cfg.stateDir}/logs'         0750 supybot supybot - -"
      "d '${cfg.stateDir}/logs/plugins' 0750 supybot supybot - -"
      "d '${cfg.stateDir}/tmp'          0750 supybot supybot - -"
      "d '${cfg.stateDir}/web'          0750 supybot supybot - -"
      "L '${cfg.stateDir}/supybot.cfg'  -    -       -       - ${cfg.configFile}"
    ];

  };
}