[gdm-list] gdm login screen with VNC

[Oleg Samarin <osamarin68 gmail com>]

Hello!

I'm trying to setup a remote desktop service on my Fedora workstation
using Gnome 3.14.2.

I use tigervnc package with xinetd. Seems everything works and I can run
"vncviewer <server>" I receive the GDM working screen. I'm able to
choose a user, to enter a password and to get a remote gnome session.

But It stops working if I install nvidia propriatary video driver on the
server: when I run "vncviewer <server>" I receive a screen with "Oh no!
Something is going wrong" and nothing working"

май 09 15:46:36 oleg2.oleghome /usr/bin/dbus-launch[999]: Xlib:  extension "GLX" missing on display 
"127.0.0.1:2".
май 09 15:46:36 oleg2.oleghome /usr/bin/dbus-launch[999]: gnome-session-is-accelerated: No hardware 3D 
support.
май 09 15:46:36 oleg2.oleghome /usr/bin/dbus-launch[999]: Xlib:  extension "GLX" missing on display 
"127.0.0.1:2".
май 09 15:46:36 oleg2.oleghome /usr/bin/dbus-launch[999]: gnome-session-check-accelerated: Helper exited with 
code 256

Seems it is a result of tigerVNC lacks a 3D-acceleration.

I managed to run a 3d-accelerated remote gnome session with the
virtualgl package:

     1. open a ssh session from the clien to the server
     2. run "vncserver" on the server. It will return a display number
     3. run "vncviewer -via <server> localhost:<display number>" on the
        client 
     4. Press "Enter" on the "Oh no" message. The black window will
        appear
     5. In the ssh session do:
                env DISPLAY=:<Display number> vglrun -c proxy gnome-session
     6. A normal gnome desktop will appear in the window of vncviewer in
        the client machine. Everything works, including glxgears and
        other 3d-applications.

"vglrun -c proxy" sets up some environment variables that force
gnome-session to use special libraries for 3d rendering and convert
3d-images to the VNC session.

But I was not able to enable this capabilities with the gdm login
screen.

I'd like to configure gdm for appending "vglrun -c proxy" every time gdm
starts gnome-session with a VNC virtual display, including for the login
screen. How can I do that?