Can't restart cups via local web interface ('unable to bind socket')

[Jarno Suni]

If I browse by Firefox to http://localhost:631/admin (to administrate CUPS) and change something and click "Change Settings" (and give my username and password if recuired) then Firefox can't establish a connection to the server at localhost:631. "sudo /etc/init.d/cupsys restart" helps. (I have enabled the web administration interface of CUPS by following the instructions at https://help.ubuntu.com/xubuntu/desktopguide/C/printer-configuration.html . I am using Xubuntu Dapper Drake)

[Daeng Bo (daengbo)]

Confirmed here in Xubuntu Edgy. The page says to wait while the server restarts, but never finishes reloading.
Unable to connect
Firefox can't establish a connection to the server at localhost:631.

[Michael Banks (michaelbanks)]

This bug also affects CUPS in the Feisty beta (2007-03-25).

From a default CUPS configuration, changing the server settings through the port 631 web interface, results in loss of connectivity to the server. A manual "/etc/init.d/cupsys restart" is required to restore access.

The error log suggests that the "cupsys" user does not have the required privileges to bind to port 631:

E [25/Mar/2007:16:30:29 +0100] Unable to bind socket for address 127.0.0.1:631 - Permission denied.
E [25/Mar/2007:16:31:19 +0100] Unable to bind socket for address 127.0.0.1:631 - Permission denied.
E [25/Mar/2007:16:31:19 +0100] cupsdStartBrowsing: Unable to bind broadcast socket - Permission denied.

This bug has been reported before (as #37986) and seems to be present in Dapper and Edgy.

[Till Kamppeter (till-kamppeter)]

This is a problem of the design of Ubuntu's non-root mode patches for CUPS.

[Jarno Suni (jarnos)]

This bug affects CUPS in the Feisty.

[lumiawaily (william-yau)]

Confirmed to have this problem on stock Feisty

/var/log/cups/error_log
E [29/May/2007:10:48:54 -0400] Unable to bind socket for address 127.0.0.1:631 - Cannot assign requested address.
E [29/May/2007:12:10:42 -0400] Creating missing directory "/var/run/cups/certs"
E [29/May/2007:20:15:45 -0400] Creating missing directory "/var/run/cups/certs"
E [29/May/2007:20:38:15 -0400] Unable to bind socket for address 127.0.0.1:631 - Cannot assign requested address.

[Milan Bouchet-Valat (nalimilan)]

Fixed in Gutsy (AFAIK). Should we mark this bug as fixed, or think of a backport? This is not likely to be possible (really new upstream version), so I set it as "Fix released".