Debian – Truly Unattended Upgrades
This will make sure you bypass those pesky questions, with the safest option. For when you want to do an upgrade in a script (such as from a Vagrant :shell provision)
DEBIAN_FRONTEND=noninteractive apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" dist-upgrade
This will make sure you bypass those pesky questions, with the safest option. For when you want to do an upgrade in a script (such as from a Vagrant :shell provision) DEBIAN_FRONTEND=noninteractive apt-get -y -o Dpkg::Options::=”–force-confdef” -o Dpkg::Options::=”–force-confold” dist-upgrade