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.

2 files changed, 39 insertions, 3 deletions

diff --git a/nixos/doc/manual/configuration/x-windows.xml b/nixos/doc/manual/configuration/x-windows.xml
index 55ad9fe6e65..06dd7c8bfb9 100644
--- a/nixos/doc/manual/configuration/x-windows.xml
+++ b/nixos/doc/manual/configuration/x-windows.xml
@@ -85,11 +85,14 @@
 <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">
diff --git a/nixos/doc/manual/release-notes/rl-2003.xml b/nixos/doc/manual/release-notes/rl-2003.xml
index f268f583f09..67e7c861eff 100644
--- a/nixos/doc/manual/release-notes/rl-2003.xml
+++ b/nixos/doc/manual/release-notes/rl-2003.xml
@@ -457,6 +457,39 @@ users.users.me =
      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>