nixos/displayManager: deprecate separate options for default wm/dm

The upstream session files display managers use have no concept of sessions being composed from
desktop manager and window manager. To be able to set upstream session files as default
session, we need a single option. Having two different ways to set default session would be confusing,
though, so we decided to deprecate the old method.

We also created separate script for each session, just like we already had a separate desktop
file for each one, and started using displayManager.sessionPackages mechanism to make the
session handling more uniform.

1 files changed, 15 insertions, 47 deletions

diff --git a/nixos/modules/services/x11/display-managers/gdm.nix b/nixos/modules/services/x11/display-managers/gdm.nix
index 095569fa08a..6630f012f04 100644
--- a/nixos/modules/services/x11/display-managers/gdm.nix
+++ b/nixos/modules/services/x11/display-managers/gdm.nix
@@ -31,44 +31,9 @@ let
     load-module module-position-event-sounds
   '';
 
-  dmDefault = config.services.xserver.desktopManager.default;
-  wmDefault = config.services.xserver.windowManager.default;
-  hasDefaultUserSession = dmDefault != "none" || wmDefault != "none";
-  defaultSessionName = dmDefault + optionalString (wmDefault != "none") ("+" + wmDefault);
-
-  setSessionScript = pkgs.python3.pkgs.buildPythonApplication {
-    name = "set-session";
-
-    format = "other";
-
-    src = ./set-session.py;
-
-    dontUnpack = true;
-
-    strictDeps = false;
-
-    nativeBuildInputs = with pkgs; [
-      wrapGAppsHook
-      gobject-introspection
-    ];
-
-    buildInputs = with pkgs; [
-      accountsservice
-      glib
-    ];
-
-    propagatedBuildInputs = with pkgs.python3.pkgs; [
-      pygobject3
-      ordered-set
-    ];
-
-    installPhase = ''
-      mkdir -p $out/bin
-      cp $src $out/bin/set-session
-      chmod +x $out/bin/set-session
-    '';
-  };
+  defaultSessionName = config.services.xserver.displayManager.defaultSession;
 
+  setSessionScript = pkgs.callPackage ./account-service-util.nix { };
 in
 
 {
@@ -186,7 +151,7 @@ in
         environment = {
           GDM_X_SERVER_EXTRA_ARGS = toString
             (filter (arg: arg != "-terminate") cfg.xserverArgs);
-          XDG_DATA_DIRS = "${cfg.session.desktops}/share/";
+          XDG_DATA_DIRS = "${cfg.sessionData.desktops}/share/";
         } // optionalAttrs (xSessionWrapper != null) {
           # Make GDM use this wrapper before running the session, which runs the
           # configured setupCommands. This relies on a patched GDM which supports
@@ -204,16 +169,19 @@ in
           cat - > /run/gdm/.config/gnome-initial-setup-done <<- EOF
           yes
           EOF
-        ''
-        # TODO: Make setSessionScript aware of previously used sessions
-        # + optionalString hasDefaultUserSession ''
-        #   ${setSessionScript}/bin/set-session ${defaultSessionName}
-        # ''
-        ;
+        '' + optionalString (defaultSessionName != null) ''
+          # Set default session in session chooser to a specified values – basically ignore session history.
+          ${setSessionScript}/bin/set-session ${cfg.sessionData.autologinSession}
+        '';
       };
 
-    # Because sd_login_monitor_new requires /run/systemd/machines
-    systemd.services.display-manager.wants = [ "systemd-machined.service" ];
+    systemd.services.display-manager.wants = [
+      # Because sd_login_monitor_new requires /run/systemd/machines
+      "systemd-machined.service"
+      # setSessionScript wants AccountsService
+      "accounts-daemon.service"
+    ];
+
     systemd.services.display-manager.after = [
       "rc-local.service"
       "systemd-machined.service"
@@ -329,7 +297,7 @@ in
       ${optionalString cfg.gdm.debug "Enable=true"}
     '';
 
-    environment.etc."gdm/Xsession".source = config.services.xserver.displayManager.session.wrapper;
+    environment.etc."gdm/Xsession".source = config.services.xserver.displayManager.sessionData.wrapper;
 
     # GDM LFS PAM modules, adapted somehow to NixOS
     security.pam.services = {