nixos/statsd: drop (#496358)

- `sing-box` has been updated to 1.13.0, which has removed some deprecated options.  See [upstream documentation](https://sing-box.sagernet.org/configuration/) for details and migration options.

- `services.statsd` has been removed because the packages it relies on do not exist anymore in nixpkgs.

- `services.tandoor-recipes` now uses a sub-directory for media files by default starting with `26.05`. Existing setups should move media files out of the data directory and adjust `services.tandoor-recipes.extraConfig.MEDIA_ROOT` accordingly. See [Migrating media files for pre 26.05 installations](#module-services-tandoor-recipes-migrating-media).

- `rustic` was upgraded to `0.11.x`, which contains breaking [changes to command-line parameters and configuration file](https://rustic.cli.rs/docs/breaking_changes.html#0110).

  ./services/monitoring/scrutiny.nix

  ./services/monitoring/smartd.nix

  ./services/monitoring/snmpd.nix

  ./services/monitoring/statsd.nix

  ./services/monitoring/sysstat.nix

  ./services/monitoring/teamviewer.nix

  ./services/monitoring/telegraf.nix

      the program being unmaintained. The options `programs.msmtp.*` can be

      used instead.

    '')

    (mkRemovedOptionModule [ "services" "statsd" ] ''

      The statsd module was removed because the packages it uses have been removed from nixpkgs.

    '')

    (mkRemovedOptionModule [ "services" "sourcehut" ] ''

      The sourcehut packages and the corresponding module have been removed due to being broken and unmaintained.

    '')

{

  config,

  lib,

  pkgs,

  ...

}:

let

  cfg = config.services.statsd;

  isBuiltinBackend =

    name:

    builtins.elem name [

      "graphite"

      "console"

      "repeater"

    ];

  backendsToPackages =

    let

      mkMap = list: name: if isBuiltinBackend name then list else list ++ [ pkgs.nodePackages.${name} ];

    in

    lib.foldl mkMap [ ];

  configFile = pkgs.writeText "statsd.conf" ''

    {

      address: "${cfg.listenAddress}",

      port: "${toString cfg.port}",

      mgmt_address: "${cfg.mgmt_address}",

      mgmt_port: "${toString cfg.mgmt_port}",

      backends: [${

        lib.concatMapStringsSep "," (

          name: if (isBuiltinBackend name) then ''"./backends/${name}"'' else ''"${name}"''

        ) cfg.backends

      }],

      ${lib.optionalString (cfg.graphiteHost != null) ''graphiteHost: "${cfg.graphiteHost}",''}

      ${lib.optionalString (cfg.graphitePort != null) ''graphitePort: "${toString cfg.graphitePort}",''}

      console: {

        prettyprint: false

      },

      log: {

        backend: "stdout"

      },

      automaticConfigReload: false${lib.optionalString (cfg.extraConfig != null) ","}

      ${cfg.extraConfig}

    }

  '';

  deps = pkgs.buildEnv {

    name = "statsd-runtime-deps";

    pathsToLink = [ "/lib" ];

    ignoreCollisions = true;

    paths = backendsToPackages cfg.backends;

  };

in

{

  ###### interface

  options.services.statsd = {

    enable = lib.mkEnableOption "statsd";

    listenAddress = lib.mkOption {

      description = "Address that statsd listens on over UDP";

      default = "127.0.0.1";

      type = lib.types.str;

    };

    port = lib.mkOption {

      description = "Port that stats listens for messages on over UDP";

      default = 8125;

      type = lib.types.port;

    };

    mgmt_address = lib.mkOption {

      description = "Address to run management TCP interface on";

      default = "127.0.0.1";

      type = lib.types.str;

    };

    mgmt_port = lib.mkOption {

      description = "Port to run the management TCP interface on";

      default = 8126;

      type = lib.types.port;

    };

    backends = lib.mkOption {

      description = "List of backends statsd will use for data persistence";

      default = [ ];

      example = [

        "graphite"

        "console"

        "repeater"

        "statsd-librato-backend"

        "statsd-influxdb-backend"

      ];

      type = lib.types.listOf lib.types.str;

    };

    graphiteHost = lib.mkOption {

      description = "Hostname or IP of Graphite server";

      default = null;

      type = lib.types.nullOr lib.types.str;

    };

    graphitePort = lib.mkOption {

      description = "Port of Graphite server (i.e. carbon-cache).";

      default = null;

      type = lib.types.nullOr lib.types.port;

    };

    extraConfig = lib.mkOption {

      description = "Extra configuration options for statsd";

      default = "";

      type = lib.types.nullOr lib.types.str;

    };

  };

  ###### implementation

  config = lib.mkIf cfg.enable {

    assertions = map (backend: {

      assertion = !isBuiltinBackend backend -> lib.hasAttrByPath [ backend ] pkgs.nodePackages;

      message = "Only builtin backends (graphite, console, repeater) or backends enumerated in `pkgs.nodePackages` are allowed!";

    }) cfg.backends;

    users.users.statsd = {

      uid = config.ids.uids.statsd;

      description = "Statsd daemon user";

    };

    systemd.services.statsd = {

      description = "Statsd Server";

      wantedBy = [ "multi-user.target" ];

      environment = {

        NODE_PATH = "${deps}/lib/node_modules";

      };

      serviceConfig = {

        ExecStart = "${pkgs.statsd}/bin/statsd ${configFile}";

        User = "statsd";

      };

    };

    environment.systemPackages = [ pkgs.statsd ];

  };

}