apt-class WAS: fai next level

[Jens Ruehmkorf]

> How about "apt-class"?

I wouldn't use anything in the apt or dpkg namespace.

> Looking into the problem slightly further, it looks like the easiest
> solution is to write out a selections file that could be installed via
> dpkg --set-selections and then use a apt-get dselect-upgrade to
> actually initiate the upgrade.

FAI's install_packages can already do what you want, although I find
dselect-upgrade somewhat irritating. OK it aims at "apt-get
dselect-upgrade", but you can use it for other things as well.

> It should be pretty easy to parse the current FAI package_config file
> format.

Yup, using regex in C

> * A package can have the following desired install states: install, hold,
>   deinstall, purge, and unknown.

You'd have to think whether it's good to mix package "selection states"
(={install, deinstall, purge}) with package "flags" (={hold}). It's a
different concept. With "unknown" you probably don't mean a regular state
but an internal state that might occur.

> * To prevent a package from being automatically upgraded it would have
>   to be placed in the "held" state, things in the unknown or install
>   states get upgraded.

See above. Besides that use /etc/apt/preferences more extensively, it
is much more powerful in some cases because of its use of regexes.

> * apt-get dselect-upgrade can deal with constructing the dependency list.
> * apt-get dselect-upgrade ignores package names that don't exist in
>   the available database. (solving the original problem with apt-get)
> * there really isn't any error handling of packages not being in the
>   archive.
>
> I was thinking of writing it in either C++ or Python, any preferences?

* use python/perl for easier maintanance, it probably makes sense to use
  perl for use with fai
* use C for wide usability (you could think of integrating it into
  debian-installer/boot-floppies once). Portability is no problem.

> Also what can be done about packages that are reading/writing to the
> console? The best solution I thought of is to provide a timer that
> can either kill the install or send email after some delay. However for
> the email to be useful the program would need to provide a way for the
> sysadmin to log into the machine and connect to the apt-get session.

Could you specify this somewhat further?

> What do people think of the rough outline of the proposed program?

some nice thoughts

--
Jens