fusa prevents ltsp sessions from logging out

On Mon, 2008-10-13 at 09:55 +0000, Oliver Grawert wrote:
> with teh new functionallity of fusa taking over the session control
> it is not possible to log out of ltsp sessions anymore (since it is
> also not possible to change users with it in real multi user
> environments like ltsp i would really like to know the base of the
> decision to change this essential bit of the desktop that late after
> UI freeze)
> please tell the ltsp team what to do in turn to be able to properly
> end ssh/ldm based sessions with it so we can use the default setup
> in intrepid.

FUSA was given a UI freeze exception and the documentation team was
notified as soon as we knew that there would be an issue.

FUSA is not taking over session management, more it is providing a menu
to do session management. I'm not sure what the issue is here, as
logout is just a call to GNOME Session manager to do logout.

Is LTSP not using GSM?

it is, but not GDM for authentication ... some call like
g_spawn_async("gnome-session --force-logout");
depending on LTSP_CLIENT would be needed instead of sending the GDM_SAFE_LOGOUT message to the GDM socket ....

bug #275031 somewhat goes hand in hand with this one, though ltsp-cluster isnt part of ubuntu in intrepid yet and they have the opportunity to just disable applets in their setup ... this is not possible for default ltsp though

sorry the above command should be gnome-session-save --force-logout ...
ltsp users are not local and dont have any access to the gdm socket at all (and there is no way to make them get access )

On Mon, 2008-10-13 at 15:50 +0000, Oliver Grawert wrote:
> sorry the above command should be gnome-session-save
> --force-logout ...
> ltsp users are not local and dont have any access to the gdm
> socket at all (and there is no way to make them get access )

So the issue is sending the command to GDM, not the use of GNOME
Session, correct?

right, ldm the ltsp display manager running on the client essentially exectutes the following command:

ssh -Y user@server /etc/X11/Xsession

which in turn parses through the different system session options and ends up calling x-session-manager (which by default is an alternative for gnome-session)

note that there is no dbus connection possible between the client and the server as there is no secure way to do this yet with dbus. so asking via dbus wont work, neither can the client nor the user that is logged in through ssh access the gdm socket, thats why i proposed to just call gnome-session-save --force-logout through g_spawn_async() if LTSP_CLIENT is set. that seems to be the smallest patch and will result in the desired behavior. LTSP_CLIENT is reliably set for all client sessions run through ldm ... though we allow admins to set up XDMCP with gdm we dont really support that for security reasons (none of the features of ltsp will work without the ssh tunnel in place anyway) but in case people use it, LTSP_CLIENT wont be set and fusa will act properly through gdm.

This bug was fixed in the package fast-user-switch-applet - 2.24.0-0ubuntu3

---------------
fast-user-switch-applet (2.24.0-0ubuntu3) intrepid; urgency=low

  * 84_session_management.patch: Add a check for the lock screen lockdown
    key and ensure that if it is set, there is no lock screen option.
    (LP: #277650)
  * 88_status_icons.patch: Adding the removal of the generated icons so
    that the package can rebuild correctly.
  * 90_status_management.patch: Reducing padding on panel. Not able to get
    rid of all, but it's better. (LP: #272824)
  * 90_status_management.patch: Adding a check for the status manager
    validity in get status. (LP: #262187)
  * 91_ltsp_new_features.patch:
   * Remove guest account with LTSP. (LP: #282610)
    * Make it so that failure to send a command to GDM on logout
      still results in logging out. (LP: #282595)
    * Hide the Reboot and shutdown items when the LTSP_CLIENT environment
      variable is set. (LP: #282613)
  * 92_autotools.patch: Update with other patches

 -- Ted Gould <email address hidden> Wed, 15 Oct 2008 22:03:35 -0500

There's an ldm task open - if something needs fixing here, then please do it - otherwise since the fusa part is fixed this bug may be closed?

no ldm changes needed, fix works fine, thanks a lot