I have set up a custom installation CD based on Debian/Ubuntu. It completely automates the installation apart from asking for the hostname and the system account's password. All was working as expected until just recently when a dialog asking to confirm a restart of services popped up, just like that shown in this question. However I'm using preseed files.
I know one could specifically give an answer to that specific package, but it's a fairly generic question that could apply to many other packages and I don't want to have to keep changing the preseed file each time.
DEBIAN_FRONTEND=noninteractive on the kernel boot line stopped it alright but also stopped it prompting the user for the hostname and password (which is what I would expect to happen to be honest).
Is there a way of doing the equivalent of
DEBIAN_FRONTEND=noninteractive and apt-get install -y in a preseed file at a specific point during the installation process so that such dialogs are suppressed from then on in (like after asking the questions and before the main block of packages get installed)?