I recently enabled comments using discourse. Continuing with my recent quest to Docker all the things, I did this using discourse_docker, which allows you to fire up a docker container with Discourse running in it. It works great.
I think that Docker goes to be the next big thing in server management and virtualization. In particular, appliances could be a big thing. In this instance I didn't have to know anything about setting up Discourse to get it up and running. I just had to follow the short set of instructions and now its whole stack is up and running with optimizations done by the creators.
This sort of thing is extremely powerful. It allows you to run great software easily. I have absolutely no experience in setting up Postgresql and yet I'm running a container with Discourse in it.