Conffiles and configuration management systems

[Scott Kitterman]

"Raphael Hertzog" <hertzog at debian.org> wrote:

>On Tue, 04 May 2010, Soren Hansen wrote:
>> Where this falls short is when you want to use a configuration
>> management tool like Puppet. Puppet is a very flexible tool. You can use
>> it to configure pretty much anything. This means that you can use it to
>> change conffiles, and in turn this means that your upgrade experience is
>> going to be very annoying: It will be riddled with questions about
>> conffiles that you allegedly changed. Except, of course, you didn't.
>> Puppet did it for you. Not only that, it often does it based on
>> declarations of various sorts rather than just a straight copy of a file
>> from a central store, so the exact changes may look foreign, even to the
>> person who made the change in Puppet.
>
>If you use puppet to manage some of your conffiles, why not stick
>"force-confold" and "force-confdef" in /etc/dpkg/dpkg.cfg ?
>
>That way the prompts are skipped... it assumes however that all modified
>files are actively managed by puppet and keeping the old version is always
>the right thing to do in that case.
>
>> Add a capability to dpkg to let tools like puppet take over this conffile
>> merging process. Or, the poor man's alternative: add a capability to
>> dpkg to ignore specific conffiles.
>
>That said I believe we want that kind of flexibility within dpkg but it
>might require some larger changes than you expect. For this reason, I
>would suggest to try to have a chat with Guillem Jover (main maintainer of
>the C part of dpkg) before the UDS session.
>
>There are also existing branches reworking the conffile handling done by
>seanius(@debian.org) so you might want to discuss with him as well.
>
>Unfortunately Guillem is hard to catch, he always has a backlog of stuff
>to respond to. :(
>
>On IRC, he's guillem or braindmg on #debian-dpkg at OFTC.

I don't believe anyone managed to talk to Guillem before the session, but I think it is OK.  The discussion ended up being fairly high level. There was strong support for the idea that this is a an area where both Debian and Ubuntu have a common interest in improvement and that the solution should be commonly developed in both Debian and Ubuntu.  I don't recall anyone speaking in favor of an. Ubuntu unique solution. 

Scott K