[Gllug] Remote X connection questions

[Bruce Richardson]

On Sat, Aug 14, 2004 at 12:54:06AM +0100, Dylan wrote:
> Hi List,
> 
> I'm setting up an audio appliance to play media files on my stereo. 
> While I'm exploring and/or writing a web-based interface, it has been 
> suggested that I use a GUI jukebox program over a remote X session. 
> I've never tried remote X login before so have some questions:
> 
> How much of X would need to be installed?
> Would it need to be configured for the server?

There is often confusion on this point, because there are two different
servers in discussion here.  One is the remote box on which the jukebox
application will run.  The other is the X server on the
desktop/laptop/PDA.  The confusion arises because many people don't
realise that an X application is an X "client".  You run an X client and
it is granted access to a display device by an X server.  To try and
make things simple, I'll refer to the box on which the jukebox
application is installed as the application server, to distinguish it
from the X server.

> Could the server be run at init 3?

No need.  You don't need to run an X server on the application server.
(Besides, runlevel 3 being associated with X is a RedHat-ism, albeit one
copied by several other rpm-based distros.)

> Would I need to install a desktop/window manager (beyond the libs needed 
> by the app)?

Not on the machine running the X application, no.  What you do is, you
run the X application on the remote host (typically via ssh) and point
it at the X server (which is running on your workstation), so that the
output is displayed on your screen.

> Can the login be made passwordless?

There are two separate authentication mechanisms here.  First of all,
there's the ssh authentication required for you to run the application
on the application server.  If you want this to be passwordless you
could use a key with no passphrase (but that would be very insecure).
More secure would be to have a key with a passphrase but to wrap your X
session in an ssh-agent session.  That means you only have to type in
your passphrase once and the authentation token lasts for the length of
the X session.

The second authentication mechanism is between the remote X client (the
jukebox application) and the local X server.  Again, ssh comes to the
rescue.  If you use the X forwarding feature of ssh, then ssh
automatically sets up the required authentication. 

Done this way, all you need to install on the application server is sshd
(configured to allow X forwarding) and the Jukebox application (and
whatever libraries or tools it depends on).  No X server or window
manager or anything else.


-- 
Bruce

Explota!: miles de lemmings no pueden estar equivocados.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 261 bytes
Desc: Digital signature
URL: <http://mailman.lug.org.uk/pipermail/gllug/attachments/20040814/97a811bb/attachment.pgp>
-------------- next part --------------
-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug