[X2go-dev] Central CUPS server not sending print jobs to physical desktop

[John A. Sullivan III]

Hello, all.  We finally have our central CUPS server running after
learning more than we ever wanted to know about NSS, LDAP, groups, and
CUPS authentication! The CUPS server is running on Lenny and we have
installed cups-x2go.  We have NOT installed x2goprint as it our
understanding from reading the documentation that it is not necessary on
the CUPS server but only on the X2Go Server.  Is this correct?

We edited the client's .kdeprintrc file to point to the central cups
server.  The client does have x2goprint installed and both the user and
x2goprint are members of the fuse group.  The client uses a non-standard
SSH port for security reasons.  We restrict access to the desktop
printers to the desktop users.  Only I can print to my desktop printer
and only Susie can print to Susie's desktop printer.  

When we print on the client to the X2Go-CUPS printer, the print job
shows as successful but the print dialog never appears on the physical
desktop.  The CUPS logs show a successful print job but no popup.

We have set up dsa key access.  If we do a ssh
-i /root/.x2go/ssh/.x2goprint/id_dsa x2goprint@<virtual desktop>, it
works - we open an ssh console without being prompted.  We have accepted
the keys into the known_hosts file for both the short and fully
qualified name.  The strange thing is that a packet trace shows no SSH
traffic.  There is plenty of CUPS traffic but the CUPS server never
tries to communicate with the virtual desktop via SSH.

If we use a local CUPS server instead, the X2Go print popup works just
fine - very impressive.  We have tried the setup with the local CUPS
server both enabled and disabled.  No difference.

What have we missed? Why does the central CUPS server not even try to
send the job to the virtual desktop? How can we troubleshoot it further?
We see nothing suspicious in the logs including the auth logs.  Thanks -
John