Hi.

Since I've upgraded my (test) LTSP server to Ubuntu 8.10, most of the 
annoying bugs I had with 8.04 LTS are gone:
- ldm displays localized messages (except "verifying password" :) )
- guest login and automatic login run fine
- local apps runs great!

Concerning "local apps", the standard LTSP5 has still one limitation:
- the /usr/share/ldm/rc.d/S01-localapps script mounts the currently 
logged user homedir under the local thin client /home. That's fine if 
you're working on your own (private) stuff and files with a local app 
(like OOO or Firefox installed in the chrooted image), but:
a) how can we access files located somewhere else, i.e in other 
directories of the server (/home/groupX, /opt/this-or-that, 
/media/disk/bigshare, etc) ?
b) When clicking on a server file icon (in Nautilus), how can we launch 
the LOCAL corresponding application instead of the server based 
application?

My (current-quick-and-dirty) solutions:
a) I've (sligthly) modified the S01-localapps script to allow other 
server directories to be mounted locally:
  - /home instead of /home/userX
  - /opt
  - /media
AFAIK, these are the only 3 directories you can safely mount locally 
without generating havoc. And these are usually the 3 Linux directories 
where you store/manage shared data (well, at least in the 25 schools 
using LTSP I'm taking care of).
In order to do so, I've added 3 new keywords in lts.conf:
   - LOCAL_REAL_HOME = True/False. If true, mounts (server)/home rather 
than /home/userX under the local /home
   - LOCAL_OPT = True/False. If true, mounts (server)/opt under the 
local /opt
   - LOCAL_MEDIA = True/False. If true, mounts (server)/media under the 
local /media

All mounts are done with sshfs. The script takes care of unmounting the 
dirs on logout. So far, it works pretty well. Now I can open /home/*, 
/opt/* or /media/* server files with my local apps (Actually Firefox, 
OOO, VLC).

b) I've also modified ltsp-localapps to handle command line parameters 
containing spaces (i.e oowriter /home/group-students/This is my 
file.odt) and/or to manage more complex syntax or additional checking. 
Although the pretty clever xprop/xatomwait channel works like a charm to 
launch local apps, it cannot handle long command lines including spaces.

So from ltsp-localapps, I've written a quick and dirty "ltsp-localapps2" 
to store the command line in a $HOMEDIR/.ltsp/prog file. Then it calls 
xprop and passes "dothis $USERNAME" to the thin client X server => 
xatomwait => ltsp-localappsd. My local "dothis" script gets the 
/home/$USERNAME/.ltsp/prog file and launches the corresponding 
command...Since "prog" is a simple bash file, additional checking can be 
done here (i.e. checks if the local apps exists, warns user if not, 
etc..). Security is maintained (script launched as temporary local 
username).

Using the same trick, it is now possible to dynamically change Nautilus 
mime extensions according to the available local apps. The S01-localapps 
script can add/update/remove (logged in user) Nautilus mime definitions 
in order to launch the local or the server based application when 
clicking on an file icon.(see 
/home/$USERNAME/.local/share/applications/mime stuff). Same script will 
clean Nautilus mime definitions (and /home/$USERNAME/.ltsp/prog) on 
logout. I've not finished this part yet (next week-end).

Qs:
- You guys from the LTSP team, are you working one something similar ?
- Security: Does this represent a security breach ?
- Having >15 thin clients mounting multiple dirs (at least 3: /home, 
/opt and /media) thru sshfs: is there a big payload on the server ? 
(Can't test it here right now)
- With OOO, Firefox, couple of additional fonts and VLC, my current 
i386.img is approx 900Mb. Same question about server load with >15 thin 
clients connected ?

I'll try to write down a recap of these modifications next week-end.

Bye,

Pierre











------------------------------------------------------------------------------
Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA
-OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise
-Strategies to boost innovation and cut costs with open source participation
-Receive a $600 discount off the registration fee with the source code: SFAD
http://p.sf.net/sfu/XcvMzF8H
_____________________________________________________________________
Ltsp-discuss mailing list.   To un-subscribe, or change prefs, goto:
      https://lists.sourceforge.net/lists/listinfo/ltsp-discuss
For additional LTSP help,   try #ltsp channel on irc.freenode.net

Reply via email to