The cloud specific documentation is only available for 3.6.x and I couldn't find it in any of the 3.7.x versions.
The 3.6.x one is outdated and the links to EGI AppDB VM images are wrong.
https://appdb.egi.eu/store/vappliance/guse.proxy.dci.bridge
https://appdb.egi.eu/store/vappliance/fedcloud.slave.dci.bridge
In addition to that the following :
Step 3
Configure the proxy DCI Bridge in the running VM.
Starts your DCI Bridge through Tomcat Manager.
Go to Cloud/Middleware settings. The Middleware settings handles the followings (Fig. 4.2):
Could get a little bit more informations as to what steps one has to go through to do that "Starts your DCI Bridge through Tomcat Manager."