I was interested in the same issue but here's what I found on Github issues:
The easiest way to get it running would be to install Discourse outside of your app. We do offer the full source code if you want to integrate with your existing login system, but I imagine it would be a fair amount of work at this point.
Right now we haven't focused much on production deployments since we're pre-beta and want to make sure people have a super easy upgrade system in place to stay on top of security holes.