nixos/display-managers/auto: remove

This module allows root autoLogin, so we would break that for users, but
they shouldn't be using it anyways. This gives the impression like auto
is some special display manager, when it's just lightdm and special pam
rules to allow root autoLogin. It was created for NixOS's testing
so I believe this is where it belongs.

nixos/doc/manual/configuration/x-windows.xml

···
 <programlisting>
 <xref linkend="opt-services.xserver.displayManager.defaultSession"/> = "none+i3";
 </programlisting>
-  And, finally, to enable auto-login for a user <literal>johndoe</literal>:
+  Every display manager in NixOS supports auto-login, here is an example
+  using lightdm for a user <literal>alice</literal>:
 <programlisting>
-<xref linkend="opt-services.xserver.displayManager.auto.enable"/> = true;
-<xref linkend="opt-services.xserver.displayManager.auto.user"/> = "johndoe";
+<xref linkend="opt-services.xserver.displayManager.lightdm.enable"/> = true;
+<xref linkend="opt-services.xserver.displayManager.lightdm.autoLogin.enable"/> = true;
+<xref linkend="opt-services.xserver.displayManager.lightdm.autoLogin.user"/> = "alice";
 </programlisting>
+  The options are named identically for all other display managers.
   </para>
  </simplesect>
  <simplesect xml:id="sec-x11-graphics-cards-nvidia">

nixos/doc/manual/release-notes/rl-2003.xml

···
      The <literal>gcc5</literal> and <literal>gfortran5</literal> packages have been removed.
     </para>
    </listitem>
+   <listitem>
+    <para>
+     The <option>services.xserver.displayManager.auto</option> module has been removed.
+     It was only intended for use in internal NixOS tests, and gave the false impression
+     of it being a special display manager when it's actually LightDM.
+     Please use the <xref linkend="opt-services.xserver.displayManager.lightdm.autoLogin"/> options instead,
+     or any other display manager in NixOS as they all support auto-login. If you used this module specifically
+     because it permitted root auto-login you can override the lightdm-autologin pam module like:
+<programlisting>
+<link xlink:href="#opt-security.pam.services._name__.text">security.pam.services.lightdm-autologin.text</link> = lib.mkForce ''
+    auth     requisite pam_nologin.so
+    auth     required  pam_succeed_if.so quiet
+    auth     required  pam_permit.so
+
+    account  include   lightdm
+
+    password include   lightdm
+
+    session  include   lightdm
+'';
+</programlisting>
+     The difference is the:
+<programlisting>
+auth required pam_succeed_if.so quiet
+</programlisting>
+     line, where default it's:
+<programlisting>
+auth required pam_succeed_if.so uid >= 1000 quiet
+</programlisting>
+     not permitting users with uid's below 1000 (like root).
+     All other display managers in NixOS are configured like this.
+    </para>
+   </listitem>
   </itemizedlist>
  </section>
 

nixos/modules/module-list.nix

···
   ./services/x11/unclutter.nix
   ./services/x11/unclutter-xfixes.nix
   ./services/x11/desktop-managers/default.nix
-  ./services/x11/display-managers/auto.nix
   ./services/x11/display-managers/default.nix
   ./services/x11/display-managers/gdm.nix
   ./services/x11/display-managers/lightdm.nix

nixos/modules/rename.nix

···
       as the underlying package isn't being maintained. Working alternatives are
       libinput and synaptics.
     '')
+    (mkRemovedOptionModule [ "services" "xserver" "displayManager" "auto" ] ''
+      The services.xserver.displayManager.auto module has been removed
+      because it was only intended for use in internal NixOS tests, and gave the
+      false impression of it being a special display manager when it's actually
+      LightDM. Please use the services.xserver.displayManager.lightdm.autoLogin options
+      instead, or any other display manager in NixOS as they all support auto-login.
+    '')
 
     # Do NOT add any option renames here, see top of the file
   ];

nixos/modules/services/x11/display-managers/auto.nix nixos/tests/common/auto.nix

···
 let
 
   dmcfg = config.services.xserver.displayManager;
-  cfg = dmcfg.auto;
+  cfg = config.test-support.displayManager.auto;
 
 in
 
···
 
   options = {
 
-    services.xserver.displayManager.auto = {
+    test-support.displayManager.auto = {
 
       enable = mkOption {
         default = false;

nixos/modules/services/x11/xserver.nix

···
 
     services.xserver.displayManager.lightdm.enable =
       let dmconf = cfg.displayManager;
-          default = !( dmconf.auto.enable
-                    || dmconf.gdm.enable
+          default = !(dmconf.gdm.enable
                     || dmconf.sddm.enable
                     || dmconf.xpra.enable );
       in mkIf (default) true;

nixos/tests/chromium.nix

···
 
   machine.imports = [ ./common/user-account.nix ./common/x11.nix ];
   machine.virtualisation.memorySize = 2047;
-  machine.services.xserver.displayManager.auto.user = "alice";
+  machine.test-support.displayManager.auto.user = "alice";
   machine.environment.systemPackages = [ chromiumPkg ];
 
   startupHTML = pkgs.writeText "chromium-startup.html" ''

nixos/tests/common/x11.nix

···
 { lib, ... }:
 
-{ services.xserver.enable = true;
+{
+  imports = [
+    ./auto.nix
+  ];
+
+  services.xserver.enable = true;
 
   # Automatically log in.
-  services.xserver.displayManager.auto.enable = true;
+  test-support.displayManager.auto.enable = true;
 
   # Use IceWM as the window manager.
   # Don't use a desktop manager.

nixos/tests/i3wm.nix

···
 
   machine = { lib, ... }: {
     imports = [ ./common/x11.nix ./common/user-account.nix ];
-    services.xserver.displayManager.auto.user = "alice";
+    test-support.displayManager.auto.user = "alice";
     services.xserver.displayManager.defaultSession = lib.mkForce "none+i3";
     services.xserver.windowManager.i3.enable = true;
   };

nixos/tests/signal-desktop.nix

···
     ];
 
     services.xserver.enable = true;
-    services.xserver.displayManager.auto.user = "alice";
+    test-support.displayManager.auto.user = "alice";
     environment.systemPackages = [ pkgs.signal-desktop ];
   };
 

nixos/tests/systemd.nix

···
     systemd.extraConfig = "DefaultEnvironment=\"XXX_SYSTEM=foo\"";
     systemd.user.extraConfig = "DefaultEnvironment=\"XXX_USER=bar\"";
     services.journald.extraConfig = "Storage=volatile";
-    services.xserver.displayManager.auto.user = "alice";
+    test-support.displayManager.auto.user = "alice";
 
     systemd.shutdown.test = pkgs.writeScript "test.shutdown" ''
       #!${pkgs.stdenv.shell}

nixos/tests/virtualbox.nix

···
       virtualisation.qemu.options =
         if useKvmNestedVirt then ["-cpu" "kvm64,vmx=on"] else [];
       virtualisation.virtualbox.host.enable = true;
-      services.xserver.displayManager.auto.user = "alice";
+      test-support.displayManager.auto.user = "alice";
       users.users.alice.extraGroups = let
         inherit (config.virtualisation.virtualbox.host) enableHardening;
       in lib.mkIf enableHardening (lib.singleton "vboxusers");

nixos/tests/xautolock.nix

···
   nodes.machine = {
     imports = [ ./common/x11.nix ./common/user-account.nix ];
 
-    services.xserver.displayManager.auto.user = "bob";
+    test-support.displayManager.auto.user = "bob";
     services.xserver.xautolock.enable = true;
     services.xserver.xautolock.time = 1;
   };

nixos/tests/xfce.nix

···
   machine =
     { pkgs, ... }:
 
-    { imports = [ ./common/user-account.nix ];
+    {
+      imports = [
+        ./common/user-account.nix
+      ];
 
       services.xserver.enable = true;
 
-      services.xserver.displayManager.auto.enable = true;
-      services.xserver.displayManager.auto.user = "alice";
+      services.xserver.displayManager.lightdm = {
+        enable = true;
+        autoLogin = {
+          enable = true;
+          user = "alice";
+        };
+      };
 
       services.xserver.desktopManager.xfce.enable = true;
 

nixos/tests/xmonad.nix

···
 
   machine = { pkgs, ... }: {
     imports = [ ./common/x11.nix ./common/user-account.nix ];
-    services.xserver.displayManager.auto.user = "alice";
+    test-support.displayManager.auto.user = "alice";
     services.xserver.displayManager.defaultSession = "none+xmonad";
     services.xserver.windowManager.xmonad = {
       enable = true;

nixos/tests/xrdp.nix

···
 
     client = { pkgs, ... }: {
       imports = [ ./common/x11.nix ./common/user-account.nix ];
-      services.xserver.displayManager.auto.user = "alice";
+      test-support.displayManager.auto.user = "alice";
       environment.systemPackages = [ pkgs.freerdp ];
       services.xrdp.enable = true;
       services.xrdp.defaultWindowManager = "${pkgs.icewm}/bin/icewm";

nixos/tests/xss-lock.nix

···
     simple = {
       imports = [ ./common/x11.nix ./common/user-account.nix ];
       programs.xss-lock.enable = true;
-      services.xserver.displayManager.auto.user = "alice";
+      test-support.displayManager.auto.user = "alice";
     };
 
     custom_lockcmd = { pkgs, ... }: {
       imports = [ ./common/x11.nix ./common/user-account.nix ];
-      services.xserver.displayManager.auto.user = "alice";
+      test-support.displayManager.auto.user = "alice";
 
       programs.xss-lock = {
         enable = true;

nixos/tests/yabar.nix

···
   machine = {
     imports = [ ./common/x11.nix ./common/user-account.nix ];
 
-    services.xserver.displayManager.auto.user = "bob";
+    test-support.displayManager.auto.user = "bob";
 
     programs.yabar.enable = true;
     programs.yabar.bars = {