[cups.general] 1.6x IPP printer detection

[Michael Sweet]

Kai,

On 2013-03-13, at 5:16 AM, Kai Hendry <hendry at webconverger.com> wrote:
> ...
> Ok, I've since discovered writing a ServerName IP to
> /etc/cups/client.conf, makes Webconverger able to detect my 1.6
> printer server.
> https://github.com/Webconverger/webc/issues/145
> 
> What protocol is this? The only downside is that I think this breaks
> in 1.6? https://bugzilla.novell.com/show_bug.cgi?id=735404#c25

ServerName specifies an alternate IPP server for the client.  By default the client looks at the local cupsd.

As for breaking things, if you are running an old CUPS without IPP/2.0 support (anything older than 1.4) then you'll need the changes coming in 1.6.2 to specify that the server only does IPP/1.1 ("ServerName host-or-ip/version=1.1").

The separate issue of the cups-filters package is an Open Printing issue - we were asked by every major Linux distro (and many users) to yield control over the Linux-specific print filters, and we did...

> This workaround avoids the Avahi install and its crazy amount of
> Python dependencies. However now my clients have the prospect of a
> poor UX by having to specify their printers IP, instead of the
> preferred "it just worked!" UX.

I didn't think Avahi needed Python to work by itself; perhaps this is a distro packaging issue?  In any case, you can also install mDNSResponder (the "other" free software mDNS stack from Apple) which definitely does not have these dependencies.


>> Additionally you may have a look at
>> https://bugzilla.novell.com/show_bug.cgi?id=735404
> 
> Pretty shocking Johannes. Noticed some of those bugs myself. :(
> 
> Extremely irritating how the config changed and the coredumps on
> restart. Wowsers bad.

We've worked very hard to fix any reported bugs, worked with the Open Printing folks to get printing working, attended regular printing summits to discuss large changes like those in CUPS 1.6, provided feedback on backwards-compatibility solutions, and generally pointed people in the right direction to get a working printing solution.  Apple hosted last year's Open Printing summit, is hosting this year's summit, and I personally have attended most of them over the past 15-or-so years.

We also have a software development process in place so that Linux distributors have time to test new versions of CUPS before they are released.  This process is in place because the automated test suite that is part of CUPS ("make check") and the limited testing we can do with a few virtual machines running different Linux distros is not typically enough for a .0 release.  Yet the 1.6 betas saw the least number of reported bugs (none from a Linux distributor) and downloads of any beta test we've had for CUPS. The result was a 1.6.0 release for Linux that had numerous problems with the Linux subsystems we interface with.  I *think* 1.6.2 (which will come out soon) will have those issues ironed out.

_________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair