I have a packer script that builds up a virtual image using Ubuntu. The script today started getting stuck during apt-get dist-upgrade on amazon-ebs: Setting up grub-pc.
I found many people on the net complaining about similar situations with various ad-hoc proposals but no clear fixing instructions. How can I fix this?
At least in my case, the problem was that the post-installation opened an interactive prompt notifying that a configuration file had been locally changed (though we don't modify it ourselves) and asking whether I want to keep the config file or use the provided new one.
I discovered this by looking at the apt-get log file: cat /var/log/apt/term.log
The solution is to force non-interactive update using both DEBIAN_FRONTEND=noninteractive environment variable and -yq option (source):
export DEBIAN_FRONTEND=noninteractive apt-get -yq dist-upgrade To my understanding this will install the new configuration version, but not 100% sure. Further insight on this would be appreciated.