I’m scripting some sys admin tasks in Debian which require the installation of packages like Postfix. I don’t want it to prompt me with questions, so I knew I had to set the priority to something higher for this specific package (i.e. temporarily). There doesn’t appear to be a way to pass this to an
apt-get command (which was a little disappointing) but debconf can set it system wide under
/var/cache/debconf/config.dat, but that’s, well, ugly.
Turns out there’s an environment variable you can set to achieve what I want, DEBIAN_PRIORITY. So exporting this variable and unsetting it post install will do the trick, but I still think
apt-get -p critical install postfix would be better