Rancid integration is fairly simple to configure.

Install and configure rancid to collect configs from your devices. Observer will currently only use a single group.

Ascertain what the path to your config repository is. I use "/var/lib/rancid" as BASEDIR and a GROUP of "network" so my configuration directory is "/var/lib/rancid/network/configs/"

Set the configuration option in the Observer config.php :

$config['rancid_configs'] = '/var/lib/rancid/network/configs/';