How do I write a Bash script to install and configure Postfix (for Debian or Ubuntu).
This is how I install Postfix:
sudo apt-get install postfix
Then I re-configure it:
sudo dpkg-reconfigure postfix
How do I make a script which automatically answers the questions of the reconfiguration with a predefined set of answers? Or is there any other way to do it?
To show the package related debconf keys and values use debconf-show packagename.
For example the package "samba-common":
To get a single key and value from commandline use echo "get samba-common/encrypt_passwords" | debconf-communicate.
To set a single key and value from commandline use echo "set samba-common/encrypt_passwords false" | debconf-communicate.
This has the advantage, that your changes will survive debian package upgrades.
All other configuration should done with teh adviced postconf utility.
Source: http://feeding.cloud.geek.nz/2010/10/manipulating-debconf-settings-on.html