[SOLVED] Running cupsd without root permission.

Question

Hello,
This is a newbie question about running the CUPS daemon as a regular user.
The Arch Wiki page on CUPS said to "start the cups ... daemon" but did not say how.
I searched the web and found that you can start it as a root user with the following command:
# cupsd
At this point, I can setup a printer, and everythings prints properly. However, I have to restart cupsd each time I reboot. Being a root only command, I can't add it to my startup script.
What do I do?
Here are some more details:
I installed 64 bit arch a few days ago.
I'm not using a desktop environment, just openbox window manager. The startup script I am using is the openbox-session autostart script.
If I run the command "cupsd" as a regular user, I get bash: /usr/bin/cupsd: Permission denied. This is how I know it will not work. This rules out a typo in the startup script.
Here is a list of all the steps/commands used to install cups:
Turn printer on
$ su
enter root password
# pacman -S cups
# pacman -S cups-filters
# pacman -S ghostscript
# pacman -S gsfonts
# pacman -S gutenprint
# cupsd
# exit
$ firefox -new-window http://localhost:631
Adding Printers and Classes
Add Printer
Login as root with the root password
Select the local printer detected
Default Name, Description, Location
Select the model: Canon PIXMA MP510
Default options
Printed a test page.
Got excited.
Spent 4 hours trying to run cupsd in a startup script.
I tried to add my regular user to the lp group.
$ su
enter root password
# gpasswd -a michael lp
$ exit
$ groups michael
confirmed that I'm added to lp
$ cupsd
I tried to chmod /usr/bin/cupsd, but got a weird error message "Child exited on signal 15". I used pacman to uninstall then reinstall cups undo this attempt.
$ su
enter root password
# chmod a+rwx /usr/bin/cupsd
# exit
$ cupsd
Some sites said to edit /etc/cups/cupsd.conf and comment out some lines. However, none of the lines mentioned exist in my /etc/cups/cupsd.conf file. I tried to comment out a few that looked close, but no success. I ended up commenting out everything and still no success. I used pacman to uninstall then reinstall cups undo this attempt, returning /etc/cups/cupsd.conf to it's original condition. Here is the file:
# "$Id: cupsd.conf.in 7888 2008-08-29 21:16:56Z mike $"
# Sample configuration file for the CUPS scheduler. See "man cupsd.conf" for a
# complete description of this file.
# Log general information in error_log - change "warn" to "debug"
# for troubleshooting...
LogLevel warn
# Only listen for connections from the local machine.
Listen localhost:631
Listen /run/cups/cups.sock
# Show shared printers on the local network.
Browsing On
BrowseLocalProtocols dnssd
# Default authentication type, when authentication is required...
DefaultAuthType Basic
# Web interface setting...
WebInterface Yes
# Restrict access to the server...
<Location />
Order allow,deny
</Location>
# Restrict access to the admin pages...
<Location /admin>
Order allow,deny
</Location>
# Restrict access to configuration files...
<Location /admin/conf>
AuthType Default
Require user @SYSTEM
Order allow,deny
</Location>
# Set the default printer/job policies...
<Policy default>
# Job/subscription privacy...
JobPrivateAccess default
JobPrivateValues default
SubscriptionPrivateAccess default
SubscriptionPrivateValues default
# Job-related operations must be done by the owner or an administrator...
<Limit Create-Job Print-Job Print-URI Validate-Job>
Order deny,allow
</Limit>
<Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
# All administration operations require an administrator to authenticate...
<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default CUPS-Get-Devices>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# All printer operations require a printer operator to authenticate...
<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# Only the owner or an administrator can cancel or authenticate a job...
<Limit Cancel-Job CUPS-Authenticate-Job>
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
<Limit All>
Order deny,allow
</Limit>
</Policy>
# Set the authenticated printer/job policies...
<Policy authenticated>
# Job/subscription privacy...
JobPrivateAccess default
JobPrivateValues default
SubscriptionPrivateAccess default
SubscriptionPrivateValues default
# Job-related operations must be done by the owner or an administrator...
<Limit Create-Job Print-Job Print-URI Validate-Job>
AuthType Default
Order deny,allow
</Limit>
<Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job Cancel-My-Jobs Close-Job CUPS-Move-Job CUPS-Get-Document>
AuthType Default
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
# All administration operations require an administrator to authenticate...
<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# All printer operations require a printer operator to authenticate...
<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After Cancel-Jobs CUPS-Accept-Jobs CUPS-Reject-Jobs>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# Only the owner or an administrator can cancel or authenticate a job...
<Limit Cancel-Job CUPS-Authenticate-Job>
AuthType Default
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
<Limit All>
Order deny,allow
</Limit>
</Policy>
# End of "$Id: cupsd.conf.in 7888 2008-08-29 21:16:56Z mike $".
Thanking those in advance that can help.
Last edited by mrallaire (2013-10-20 05:37:52)

Answer 1

Well, the problem is now resolved. After using my wife's printer for 1.5 months I finally had the time to try it again. I got it working. I entered a lot of different commands, but the following is what finally did the trick. The ideas came from ThomasR on another forum post: https://bbs.archlinux.org/viewtopic.php?id=35567
<code>
# killall cupsd
# groupadd printadmin
# usermod -aG printadmin myusername
# nano /etc/cups/cupsd.conf
Add the following to the bottom of the file and save:
   SystemGroup printadmin
# cupsd
Add the printer using the web-based administration interface (in the web browser, go to URL http://localhost:631)
</code>
I looks like the lp group stuff that I entered in my first post was a few commands short of being effective. The printadmin group commands worked wonderfully. After rebooting the computer the change stuck, so I never had to restart the cups daemon each time I rebooted the computer.
I don't know what way is better to start the cups daemon, cupsd or systemctl.
<code>
# cupsd
vs.
# systemctl enable cups.service
# systemctl start cups.service
</code>