[LightDM] Can LightDM work with an existing X server socket?

[Shahim Essaid]

Robert,

I tried the configuration you suggested but there must be something
else I am missing.

I'm trying this in Ubuntu 13.10 64 bit with LightDM 1.8.4. My host
name is "desktop".  I have the socket as /tmp/.X11-unix/X6 and if I
do:

export DISPLAY=:6
xterm

I get the xterm window on the display. I have access control disabled
in X for now.

I started with the LightDM configuration you suggested and then added
few more lines to make the server name look right in the logs. Here is
my configuration and the error in the log:


[LightDM]
start-default-seat=false
minimum-display-number=6
minimum-vt=6

[Seat:6]
type=xremote
xserver-display-number=6
xserver-share = true  # I had the same error without this line and the next one
xserver-hostname = desktop/unix # without this the display name would
be localhost:6

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.8.4, UID=0 PID=984
[+0.00s] DEBUG: Loading configuration from
/etc/lightdm/lightdm.conf.d/10-ubuntu.conf
[+0.00s] DEBUG: Loading configuration from
/etc/lightdm/lightdm.conf.d/50-greeter-wrapper.conf
[+0.00s] DEBUG: Loading configuration from
/etc/lightdm/lightdm.conf.d/50-guest-wrapper.conf
[+0.00s] DEBUG: Loading configuration from
/etc/lightdm/lightdm.conf.d/50-unity-greeter.conf
[+0.00s] DEBUG: Loading configuration from
/etc/lightdm/lightdm.conf.d/50-xserver-command.conf
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Using Xephyr for X servers
[+0.00s] DEBUG: Registered seat module xlocal
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Registered seat module surfaceflinger
[+0.00s] DEBUG: Loading seat Seat:6
[+0.00s] DEBUG: Seat 6: Starting
[+0.00s] DEBUG: Seat 6: Creating greeter session
[+0.00s] DEBUG: Seat 6: Setting XDG_SEAT=seat0
[+0.00s] DEBUG: Seat 6: Creating display server of type x
[+0.00s] DEBUG: Seat 6: Starting remote X display desktop/unix:6
[+0.00s] DEBUG: DisplayServer x-desktop/unix-6: Connecting to XServer
desktop/unix:6
[+0.00s] DEBUG: DisplayServer x-desktop/unix-6: Error connecting to
XServer desktop/unix:6
[+0.00s] DEBUG: Seat 6: Can't create display server for greeter
[+0.00s] DEBUG: Seat 6: Session stopped
[+0.00s] DEBUG: Seat 6: Stopping; failed to start a greeter
[+0.00s] DEBUG: Seat 6: Stopping
[+0.00s] DEBUG: Seat 6: Stopping display server
[+0.00s] DEBUG: Seat 6: Display server stopped
[+0.00s] DEBUG: Seat 6: Stopped
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager


>From the log it looks like LightDM is trying to start a new display.
Any thoughts about what I am doing wrong?

Thanks,
Shahim


On Wed, Nov 13, 2013 at 8:17 PM, Robert Ancell <robert.ancell at gmail.com> wrote:
> Hi Shahim,
>
> You should be able to configure LightDM to use an existing X server using
> the following configuration:
>
> [SeatDefaults]
> type=xremote
> xserver-display-number=0
>
> i.e. if you already have an X server running on :0
>
> --Robert
>
>
> On 14 November 2013 11:56, Shahim Essaid <shahim at essaid.com> wrote:
>>
>> Hi all,
>>
>> I'm setting up an LXC container for Ubuntu 13.10 where the X server is
>> started in the host on vt6. The unix socket and authority file are
>> then mounted in the LXC container. I can start X sessions and
>> applications from the container but I can't get LightDM to use this
>> server.
>>
>> I would really like to have the container's LightDM/Ubuntu greeter to
>> automatically start on this display when the container is started to
>> allow a graphical login. I'm aware of other options (XDMCP, vnc, etc.)
>> but I'm trying to do it directly through the mounted unix domain
>> socket. I've been trying to configure X to be started and managed by
>> LightDM in the container but haven't been able to do that so far.
>>
>> Is this possible?
>>
>> Thank you,
>> Shahim
>> _______________________________________________
>> LightDM mailing list
>> LightDM at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/lightdm
>
>