Package installation based on package priority

Hi
I would like to install all Debian packages from priority important and
standard in a FAI disk image.

I am using now grep-aptvail and xargs to find this out, like in the
following shell snippet config_space/scripts/VAGRANT/20-setup


chroot $target grep-aptavail --no-field-names --show-field Package
--field Priority --regex 'standard\|important' \
  | chroot $target xargs apt install --yes

Is there any way to have the same behaviour using a package_config entry ?

Emmanuel

-- 
You know an upstream is nice when they even accept m68k patches.
  - John Paul Adrian Glaubitz, Debian OpenJDK maintainer