light-locker (lockscreen for lightdm)

nixos/modules/services/x11/display-managers/default.nix

@@ -37,7 +37,7 @@ let
   # file provided by services.xserver.displayManager.session.script
   xsession = wm: dm: pkgs.writeScript "xsession"
     ''
-      #! /bin/sh
+      #! ${pkgs.bash}/bin/bash
 
       . /etc/profile
       cd "$HOME"

nixos/modules/services/x11/display-managers/lightdm.nix

@@ -13,9 +13,16 @@ let
   # lightdm runs with clearenv(), but we need a few things in the enviornment for X to startup
   xserverWrapper = writeScript "xserver-wrapper"
     ''
-      #! /bin/sh
+      #! ${pkgs.bash}/bin/bash
       ${concatMapStrings (n: "export ${n}=\"${getAttr n xEnv}\"\n") (attrNames xEnv)}
-      exec ${dmcfg.xserverBin} ${dmcfg.xserverArgs}
+
+      display=$(echo "$@" | xargs -n 1 | grep -P ^:\\d\$ | head -n 1 | sed s/^://)
+      if [ -z "$display" ]
+      then additionalArgs=":0 -logfile /var/log/X.0.log"
+      else additionalArgs="-logfile /var/log/X.$display.log"
+      fi
+
+      exec ${dmcfg.xserverBin} ${dmcfg.xserverArgs} $additionalArgs "$@"
     '';
 
   usersConf = writeText "users.conf"
@@ -39,7 +46,6 @@ let
       greeter-session = ${cfg.greeter.name}
       ${cfg.extraSeatDefaults}
     '';
-
 in
 {
   # Note: the order in which lightdm greeter modules are imported
@@ -98,7 +104,6 @@ in
   };
 
   config = mkIf cfg.enable {
-
     services.xserver.displayManager.slim.enable = false;
 
     services.xserver.displayManager.job = {
@@ -149,5 +154,7 @@ in
 
     services.xserver.displayManager.lightdm.background = mkDefault "${pkgs.nixos-artwork}/share/artwork/gnome/Gnome_Dark.png";
 
+    services.xserver.tty     = null; # We might start multiple X servers so let the tty increment themselves..
+    services.xserver.display = null; # We specify our own display (and logfile) in xserver-wrapper up there
   };
 }

nixos/modules/services/x11/xserver.nix

@@ -381,13 +381,13 @@ in
       };
 
       tty = mkOption {
-        type = types.int;
+        type = types.nullOr types.int;
         default = 7;
         description = "Virtual console for the X server.";
       };
 
       display = mkOption {
-        type = types.int;
+        type = types.nullOr types.int;
         default = 0;
         description = "Display number for the X server.";
       };
@@ -517,11 +517,12 @@ in
     services.xserver.displayManager.xserverArgs =
       [ "-ac"
         "-terminate"
-        "-logfile" "/var/log/X.${toString cfg.display}.log"
         "-config ${configFile}"
-        ":${toString cfg.display}" "vt${toString cfg.tty}"
         "-xkbdir" "${pkgs.xkeyboard_config}/etc/X11/xkb"
-      ] ++ optional (!cfg.enableTCP) "-nolisten tcp";
+      ] ++ optional (cfg.display != null) ":${tostring cfg.display}"
+        ++ optional (cfg.tty     != null) "vt${toString cfg.tty}"
+        ++ optional (cfg.display != null) [ "-logfile" "/var/log/X.${toString cfg.display}.log" ]
+        ++ optional (!cfg.enableTCP) "-nolisten tcp";
 
     services.xserver.modules =
       concatLists (catAttrs "modules" cfg.drivers) ++

pkgs/misc/screensavers/light-locker/default.nix

@@ -0,0 +1,43 @@
+{ stdenv
+, fetchFromGitHub
+, which
+, xfce
+, glib
+, pkgconfig
+, libX11
+, gtk3
+, dbus_glib
+, systemd
+, wrapGAppsHook
+}:
+
+stdenv.mkDerivation rec {
+  name = "${basename}-${version}";
+  basename = "light-locker";
+  version = "1.7.0";
+
+  src = fetchFromGitHub {
+    owner = "the-cavalry";
+    repo = basename;
+    rev = "v${version}";
+    sha256 = "0ygkp5vgkx2nfhfql6j2jsfay394gda23ir3sx4f72j4agsirjvj";
+  };
+
+  buildInputs = [ which xfce.xfce4_dev_tools glib pkgconfig libX11 gtk3 dbus_glib systemd wrapGAppsHook ];
+
+  preConfigure = ''
+    ./autogen.sh
+  '';
+
+  meta = with stdenv.lib; {
+    homepage = https://github.com/the-cavalry/light-locker;
+    description = "light-locker is a simple locker";
+    longDescription = ''
+      light-locker is a simple locker (forked from gnome-screensaver) that aims to have simple, sane, secure defaults and be well integrated with the desktop while not carrying any desktop-specific dependencies.
+      It relies on lightdm for locking and unlocking your session via ConsoleKit/UPower or logind/systemd.
+    '';
+    license = licenses.gpl2;
+    maintainers = with maintainers; [ obadz ];
+    platforms = platforms.linux;
+  };
+}

pkgs/top-level/all-packages.nix

@@ -7707,6 +7707,8 @@ let
 
   lightning = callPackage ../development/libraries/lightning { };
 
+  lightlocker = callPackage ../misc/screensavers/light-locker { };
+
   lirc = callPackage ../development/libraries/lirc { };
 
   liquidfun = callPackage ../development/libraries/liquidfun { };