Where does debconf database content come from?

[Yuri Kanivetsky <yuri.kanivetsky@gmail.com>]

Hi,

For all I know, debconf database is supposed to store "answers" to
configuration parameters of packages. But when you install operating
system, you aren't given an opportunity to specify them. Not all of
them at least. There are a bunch of them in
/var/cache/debconf/config.dat.

So where do all of them come from? Does debian comes with default
config.dat? Does it contain values for all the packages? For some
predefined set of them? Which package owns it? Or generates?

I've run into it trying to set up lxc container. There where
differences between releases. So I started to dig into where they're
coming from. The issue was with resolvconf package and
resolvconf/link-tail-to-original parameter.

Regards,
Yuri