1 files changed, 57 insertions, 7 deletions

diff --git a/nixpkgs/nixos/modules/services/x11/display-managers/default.nix b/nixpkgs/nixos/modules/services/x11/display-managers/default.nix
index aa6a5ec42be..08ce8edd661 100644
--- a/nixpkgs/nixos/modules/services/x11/display-managers/default.nix
+++ b/nixpkgs/nixos/modules/services/x11/display-managers/default.nix
@@ -55,13 +55,6 @@ let
         exec &> >(tee ~/.xsession-errors)
       ''}
 
-      # Tell systemd about our $DISPLAY and $XAUTHORITY.
-      # This is needed by the ssh-agent unit.
-      #
-      # Also tell systemd about the dbus session bus address.
-      # This is required by user units using the session bus.
-      /run/current-system/systemd/bin/systemctl --user import-environment DISPLAY XAUTHORITY DBUS_SESSION_BUS_ADDRESS
-
       # Load X defaults. This should probably be safe on wayland too.
       ${xorg.xrdb}/bin/xrdb -merge ${xresourcesXft}
       if test -e ~/.Xresources; then
@@ -70,6 +63,12 @@ let
           ${xorg.xrdb}/bin/xrdb -merge ~/.Xdefaults
       fi
 
+      # Import environment variables into the systemd user environment.
+      ${optionalString (cfg.displayManager.importedVariables != []) (
+        "/run/current-system/systemd/bin/systemctl --user import-environment "
+          + toString (unique cfg.displayManager.importedVariables)
+      )}
+
       # Speed up application start by 50-150ms according to
       # http://kdemonkey.blogspot.nl/2008/04/magic-trick.html
       rm -rf "$HOME/.compose-cache"
@@ -289,6 +288,14 @@ in
         '';
       };
 
+      importedVariables = mkOption {
+        type = types.listOf (types.strMatching "[a-zA-Z_][a-zA-Z0-9_]*");
+        visible = false;
+        description = ''
+          Environment variables to import into the systemd user environment.
+        '';
+      };
+
       job = {
 
         preStart = mkOption {
@@ -332,12 +339,45 @@ in
 
       };
 
+      # Configuration for automatic login. Common for all DM.
+      autoLogin = mkOption {
+        type = types.submodule {
+          options = {
+            enable = mkOption {
+              type = types.bool;
+              default = cfg.displayManager.autoLogin.user != null;
+              description = ''
+                Automatically log in as <option>autoLogin.user</option>.
+              '';
+            };
+
+            user = mkOption {
+              type = types.nullOr types.str;
+              default = null;
+              description = ''
+                User to be used for the automatic login.
+              '';
+            };
+          };
+        };
+
+        default = {};
+        description = ''
+          Auto login configuration attrset.
+        '';
+      };
+
     };
 
   };
 
   config = {
     assertions = [
+      { assertion = cfg.displayManager.autoLogin.enable -> cfg.displayManager.autoLogin.user != null;
+        message = ''
+          services.xserver.displayManager.autoLogin.enable requires services.xserver.displayManager.autoLogin.user to be set
+        '';
+      }
       {
         assertion = cfg.desktopManager.default != null || cfg.windowManager.default != null -> cfg.displayManager.defaultSession == defaultSessionFromLegacyOptions;
         message = "You cannot use both services.xserver.displayManager.defaultSession option and legacy options (services.xserver.desktopManager.default and services.xserver.windowManager.default).";
@@ -360,6 +400,16 @@ in
 
     services.xserver.displayManager.xserverBin = "${xorg.xorgserver.out}/bin/X";
 
+    services.xserver.displayManager.importedVariables = [
+      # This is required by user units using the session bus.
+      "DBUS_SESSION_BUS_ADDRESS"
+      # These are needed by the ssh-agent unit.
+      "DISPLAY"
+      "XAUTHORITY"
+      # This is required to specify session within user units (e.g. loginctl lock-session).
+      "XDG_SESSION_ID"
+    ];
+
     systemd.user.targets.graphical-session = {
       unitConfig = {
         RefuseManualStart = false;