udisks2: add udisks2 service

Udisks2 is a Dbus service started by systemd on demand.

modules/module-list.nix

@@ -82,6 +82,7 @@
   ./services/hardware/sane.nix
   ./services/hardware/udev.nix
   ./services/hardware/udisks.nix
+  ./services/hardware/udisks2.nix
   ./services/hardware/upower.nix
   ./services/logging/klogd.nix
   ./services/logging/logcheck.nix

modules/services/hardware/udisks2.nix

@@ -0,0 +1,53 @@
+# Udisks daemon.
+
+{ config, pkgs, ... }:
+
+with pkgs.lib;
+
+{
+
+  ###### interface
+
+  options = {
+
+    services.udisks2 = {
+
+      enable = mkOption {
+        default = false;
+        description = ''
+          Whether to enable Udisks, a DBus service that allows
+          applications to query and manipulate storage devices.
+        '';
+      };
+
+    };
+
+  };
+
+
+  ###### implementation
+
+  config = mkIf config.services.udisks2.enable {
+
+    environment.systemPackages = [ pkgs.udisks2 ];
+
+    services.dbus.packages = [ pkgs.udisks2 ];
+
+    system.activationScripts.udisks2 =
+      ''
+        mkdir -m 0755 -p /var/lib/udisks2
+      '';
+
+    #services.udev.packages = [ pkgs.udisks2 ];
+    
+    systemd.services.udisks2 = {
+      description = "Udisks2 service";
+      serviceConfig = {
+        Type = "dbus";
+        BusName = "org.freedesktop.UDisks2";
+        ExecStart = "${pkgs.udisks2}/lib/udisks2/udisksd --no-debug";
+      };
+    };
+  };
+
+}