Hey,
Caolán and I have been working on prototyping a VNC based terminal
services system which also allows hot-desking.
The idea is that we allow GDM to accept VNC connections, spawn a VNC
server for each new connection and display a login screen. The user then
authenticates through the login screen as normal and GDM starts a new
session on the VNC server. However, if you then close your VNC client,
the session doesn't go away. GDM continues to manage that session.
You may then go to a different terminal, the server will spawn off a
new VNC server with a login screen through which you log in. However,
once you log in, GDM detects that you already have a session running and
switches you to your original session rather than starting a new
session.
You could imagine terminals which are very similar to LTSP terminals,
but instead of starting an X server which queries the server for a login
using XDMCP, it starts a fullscreen vncviewer which connects to the
server.
We've reached a stage where we can demo the basic idea, so here's the
results:
1) On a test machine which will act as the terminal server, install
the "gdm" and "vnc-server" packages from:
http://people.redhat.com/markmc/terminal-services-demo
Note: there are packages built against both FC2 and rawhide.
2) Punch port 5900 through the firewall on the server - i.e.
system-config-securitylevel, Other ports, "5900:tcp"
3) Reboot for good luck.
4) From another machine, vncviewer -FullScreen -FullColor myserver
5) Log in as normal, play around, start a few apps.
6) Close vncviewer (F8, Exit viewer)
7) Start vncviewer as in (4)
8) Log in as normal, you should be immediately switched back to your
original session.
Caveats:
+ You don't want install these packages on a machine which you need to
stay working. We're making no stability/security guarantees
whatsoever yet.
+ The VNC protocol stream is unencrypted. When you type in your
password to the login screen its going across the network in plain
text. Don't test this on an untrusted network. We'll be making all
this work using the SSL extension used in Vino[1].
+ Right now, the client will be encoding the pixels using the "raw"
encoding. No compression, so it'll be slow. We'll be fixing that
soon too.
Cheers,
Mark.
[1] - http://www.gnome.org/~markmc/blog/05022004
