{ config, lib, pkgs, ... }: with lib; 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.${name} ]; in foldl mkMap []; configFile = pkgs.writeText "statsd.conf" '' { address: "${cfg.listenAddress}", port: "${toString cfg.port}", mgmt_address: "${cfg.mgmt_address}", mgmt_port: "${toString cfg.mgmt_port}", backends: [${ concatMapStringsSep "," (name: if (isBuiltinBackend name) then ''"./backends/${name}"'' else ''"${name}"'' ) cfg.backends}], ${optionalString (cfg.graphiteHost!=null) ''graphiteHost: "${cfg.graphiteHost}",''} ${optionalString (cfg.graphitePort!=null) ''graphitePort: "${toString cfg.graphitePort}",''} console: { prettyprint: false }, log: { backend: "stdout" }, automaticConfigReload: false${optionalString (cfg.extraConfig != null) ","} ${cfg.extraConfig} } ''; deps = pkgs.buildEnv { name = "statsd-runtime-deps"; pathsToLink = [ "/lib" ]; ignoreCollisions = true; paths = backendsToPackages cfg.backends; }; in { ###### interface options.services.statsd = { enable = mkEnableOption "statsd"; listenAddress = mkOption { description = "Address that statsd listens on over UDP"; default = "127.0.0.1"; type = types.str; }; port = mkOption { description = "Port that stats listens for messages on over UDP"; default = 8125; type = types.int; }; mgmt_address = mkOption { description = "Address to run management TCP interface on"; default = "127.0.0.1"; type = types.str; }; mgmt_port = mkOption { description = "Port to run the management TCP interface on"; default = 8126; type = types.int; }; backends = mkOption { description = "List of backends statsd will use for data persistence"; default = []; example = [ "graphite" "console" "repeater" "statsd-librato-backend" "stackdriver-statsd-backend" "statsd-influxdb-backend" ]; type = types.listOf types.str; }; graphiteHost = mkOption { description = "Hostname or IP of Graphite server"; default = null; type = types.nullOr types.str; }; graphitePort = mkOption { description = "Port of Graphite server (i.e. carbon-cache)."; default = null; type = types.nullOr types.int; }; extraConfig = mkOption { description = "Extra configuration options for statsd"; default = ""; type = types.nullOr types.str; }; }; ###### implementation config = mkIf cfg.enable { assertions = map (backend: { assertion = !isBuiltinBackend backend -> hasAttrByPath [ backend ] pkgs.nodePackages; message = "Only builtin backends (graphite, console, repeater) or backends enumerated in `pkgs.nodePackages` are allowed!"; }) cfg.backends; users.extraUsers = singleton { name = "statsd"; uid = config.ids.uids.statsd; description = "Statsd daemon user"; }; systemd.services.statsd = { description = "Statsd Server"; wantedBy = [ "multi-user.target" ]; environment = { NODE_PATH = "${deps}/lib/node_modules"; }; serviceConfig = { ExecStart = "${pkgs.statsd}/bin/statsd ${configFile}"; User = "statsd"; }; }; environment.systemPackages = [ pkgs.statsd ]; }; }