Printing V

Configuring the CUPS Service


The CUPS service is configured using several text files within the
/etc/cups directory.


The


/etc/cups/cupsd.conf



file is the main configuration file you will use to configure the cupsd
daemon (calledt he scheduler). Remember that cupsd is also an HTTP server,
like Apache. Accordingly, the cupsd.conf file is very similar to the Apache
web server configuration file.




A sample cupsd .conf file is shown in Figure 16-4.



Figure 16-4 only shows a very small portion of the cupsd.conf file,
which is quite long. The cupsd.conf file is composed of many server
directives, which specify how cupsd operates. We don’t have the time
or space in this book to cover all the configuration options in
cupsd.conf. I’m just going to cover the most important ones here. For
more information, see the man page for cupsd.conf. You can also open



http://localhost:631/help/ 


in a browser on your Linux system to see an extensive list of cupsd.conf directives,
or you can visit



http://www.cups.org/documentation.php/ref-cupsd-conf.html 



Some of the more useful cupsd.conf directives include those shown in Table
16-1.




The way you configure cupsd.conf will largely depend on the particular
network you are implementing the system in. The good news is that you
don’t need to do much with cupsd.conf to configure a basic
implementation that provides local printing.



However, if you want other Linux systems to be able to print through
your CUPS printer, you must


enable BrowseAddress 


or else CUPS won’t announce its printers on the network. This directive is
not enabled by default on many distributions. Sample configurations for this
directive include the following:



BrowseAddress 255.255.255.255:631

BrowseAddress 192.168.1.255:631

BrowseAddress mydom.com:631

BrowseAddress @LOCAL




The BrowseAddress directive is usually set to a value of @LOCAL.



This causes CUPS to send printer announcement broadcasts to all local
network interfaces in the system.


You can set this directive to


@IF(interface_name) 



to limit broadcasts to a specific network interface.




After making any changes to cupds.conf, be sure to restart the cupsd
daemon. 



After configuring your cupsd.conf file, you next need to set
up a Linux user account that will be used as the CUPS administrator.


CUPS does not use the same user accounts that your Linux system uses.


Instead, CUPS is configured to use the


/etc/cups/passwd.md5 


file to store user accounts.


To create an administrative user in the passwd.md5 file named root that
is a member of the CUPS administration group named sys, you would enter



lppasswd –g sys –a root









LX0-104 Exam Objectives (Q)