Add statsd, simple daemon for easy stats aggregation

modules/misc/ids.nix

@@ -81,6 +81,7 @@ in
     supybot = 65;
     iodined = 66;
     graphite = 68;
+    statsd = 69;
 
     # When adding a uid, make sure it doesn't match an existing gid.
 

modules/module-list.nix

@@ -125,6 +125,7 @@
   ./services/monitoring/monit.nix
   ./services/monitoring/nagios/default.nix
   ./services/monitoring/smartd.nix
+  ./services/monitoring/statsd.nix
   ./services/monitoring/systemhealth.nix
   ./services/monitoring/ups.nix
   ./services/monitoring/uptime.nix

modules/services/monitoring/statsd.nix

@@ -0,0 +1,94 @@
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+let
+
+  cfg = config.services.statsd;
+
+  configFile = pkgs.writeText "statsd.conf" ''
+    {
+      host: "${cfg.host}",
+      port: "${toString cfg.port}",
+      backends: [${concatMapStrings (el: ''"./backends/${el}",'') cfg.backends}],
+      graphiteHost: "${cfg.graphiteHost}",
+      graphitePort: "${toString cfg.graphitePort}",
+      ${cfg.extraConfig}
+    }
+  '';
+
+in
+
+{
+
+  ###### interface
+
+  options.services.statsd = {
+
+    enable = mkOption {
+      description = "Whether to enable statsd stats aggregation service";
+      default = false;
+      type = types.uniq types.bool;
+    };
+
+    host = mkOption {
+      description = "Address that statsd listens on over UDP";
+      default = "127.0.0.1";
+      type = types.uniq types.string;
+    };
+
+    port = mkOption {
+      description = "Port that stats listens for messages on over UDP";
+      default = 8125;
+      type = types.uniq types.int;
+    };
+
+    backends = mkOption {
+      description = "List of backends statsd will use for data persistance";
+      default = ["graphite"];
+    };
+
+    graphiteHost = mkOption {
+      description = "Hostname or IP of Graphite server";
+      default = "127.0.0.1";
+      type = types.uniq types.string;
+    };
+
+    graphitePort = mkOption {
+      description = "Port of Graphite server";
+      default = 2003;
+      type = types.uniq types.int;
+    };
+
+    extraConfig = mkOption {
+      default = "";
+      description = "Extra configuration options for statsd";
+      type = types.uniq types.string;
+    };
+
+  };
+
+  ###### implementation
+
+  config = mkIf cfg.enable {
+
+    users.extraUsers = singleton {
+      name = "statsd";
+      uid = config.ids.uids.statsd;
+      description = "Statsd daemon user";
+    };
+
+    systemd.services.statsd = {
+      description = "Statsd Server";
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        ExecStart = "${pkgs.nodePackages.statsd}/bin/statsd ${configFile}";
+        User = "statsd";
+      };
+    };
+
+    environment.systemPackages = [pkgs.nodePackages.statsd];
+
+  };
+
+}