Silence apt-get for real

[Lars Roland <lroland@gmail.com>]

Hi all

I have a repository that I use to distribute my own (and 3rd-party)
packages to all my debian servers (20 servers placed around the
world).

I test the upgrades before putting them in my repository and then I
have cron script on each of the servers that runs the following

apt-get update
apt-get upgrade -y --force-yes -qq

this was supposed to silence apt-get completely and make it choose
default values for all questions. However if I have package that
contains a file and this file is changed in between updates then I get
the following:

------------------
Configuration file `/etc/qmail/tcp.smtp'
  ==> Modified (by you or by a script) since installation.
  ==> Package distributor has shipped an updated version.
    What would you like to do about it ?  Your options are:
     Y or I  : install the package maintainer's version
     N or O  : keep your currently-installed version
       D     : show the differences between the versions
       Z     : background this process to examine the situation
  The default action is to keep your current version.
*** tcp.smtp (Y/I/N/O/D/Z) [default=N] ? n
------------------

How can I get rid of this warning ? - I want apt-get to be completely
silent. I know that this could be dangerous - but in my case it is ok
given that it is me that control the repository and that I have tested
all the packages before putting them there.

So to put it short how do I silence apt-get completely ?.


Regards.

Lars Roland