Automating Setup

You can automate the Setup process using sosetup.conf.

Copy the example file to your home directory:

cp /usr/share/securityonion/sosetup.conf ~

Edit your new sosetup.conf using nano or your favorite text editor:

nano ~/sosetup.conf

Run Setup with the -f switch and the path to this file:

sudo sosetup -f ~/sosetup.conf

As of securityonion-setup - 20120912-0ubuntu0securityonion201, sosetup now supports a -w switch that allows you to answer the standard Setup questions and have it write out your custom sosetup.conf:
http://blog.securityonion.net/2016/03/securityonion-setup-20120912.html