Defina DEBIAN_FRONTEND como noninteractive :
DEBIAN_FRONTEND=noninteractive apt-get ...
Isso também se aplica a dpkg --reconfigure , dpkg-configure , etc.
Em man 7 debconf :
noninteractive
This is the anti-frontend. It never interacts with you at all,
and makes the default answers be used for all questions. It
might mail error messages to root, but that's it; otherwise it
is completely silent and unobtrusive, a perfect frontend for
automatic installs. If you are using this front-end, and require
non-default answers to questions, you will need to preseed the
debconf database; see the section below on Unattended Package
Installation for more details.
Se você definir noninteractive , deverá considerar responder debconf de perguntas usando debconf-set-selections .