[Triumf-linux-managers] Printing

[Kelvin Raywood]

I finally got around to implementing a suggestion that Denice Deatrich 
made last year.  She suggested that people don't need to run the cups 
daemon (printing service) on their individual workstations.  You can 
just point to the our print server directly.  This has the advantage of 
not picking up spurious printer shares by other machines on the network, 
and also enables you to examine the print queues and cancel jobs 
directly on your own machine.  Also, it protects you from losing the 
print queues when cups on your local machine crashes which has been know 
to happen.  There are several ways to implement this change.

_Using TRIUMF rpms_

Those of you using the TRIUMF rpms (SL4.5 or higher from TRIUMF 
kickstart CD) will have received an update to triumf-workstation 
overnight; presuming that your nightly yum update is enabled. An 
additional rpm "triumf-printers" was added as a requirement to 
triumf-workstation.  This rpm adds three files.

     /etc/profile.d/triumf-printers.sh
     /etc/profile.d/triumf-printers.csh
     /etc/X11/xinit/xinitrc.d/triumf-printers.sh

These files set "CUPS_SERVER=printers.triumf.ca" the next time that you 
login.  With this in your environment, it is not necessary to run the 
cups daemon locally so the rpm also disables the cups service from 
starting automically at next reboot.  (chkconfig cups off).  However, to 
avoid interruptions, it does not stop the service if it is currently 
running.  Once you have logged out and in, you can stop the cups service 
manually as it is no longer needed.


_Doing it manually_

If you haven't upgraded to using the TRIUMF rpms, then the easiest way 
to do this for all users on the machine is to edit /etc/cups/client.conf
and append the following line.

ServerName printers.triumf.ca


_Checking the queues_

Before the changes the output of "lpstat -s" will contain lines like:
   device for Xerox01: ipp://trprint.triumf.ca:631/printers/Xerox01

After logging out and in (TRIUMF rpms) or manually changing 
/etc/cups/client.conf, "lpstat -s" will produce:
   device for Xerox01: ipp://xerox01.triumf.ca

This does not mean that you are printing directly to the printers.  It 
is just showing you the definitions from the server.

Similarly, "lpstat -o" shows all the jobs in all the queues.

--
Kel Raywood
TRIUMF Network and Computing Services