We've had a few questions like this, and even though I've already spoken with hedisam I wanted to post here for everyone's benefit.
At times people have the impression that DreamFactory generates backend services, such as databases, on the fly. Just type in the credentials you want to use and click Create Service.
This is NOT the case.
DreamFactory automatically generates APIs for services that you already manage externally, or perhaps even on the same server. You provide the connection information, and DreamFactory generates the APIs for you.
The confusion seems to come from the fact that Bitnami, who packages the containered installers and images for us now includes MySQL and MongoDB already running and configured -- a great benefit.