Checkout http://deis.io/ and follow the Heroku buildpack instructions to take some of the headache out of all the DevOps questions that Dockerfiles etc might pose if you are just a humble web developer. Deis run's on CoreOS which is an excellent base OS that requires you to use Docker. CoreOS upgrades automatically in the background too.

Deis is a fully opensource PaaS inspired by Heroku. You can dip your toe in the water by spinning up a Deis cluster and then just following the Heroku inspired/compatible workflow described in the Deis docs. When you are ready to experiment Deis let's you use Dockerfiles instead of a Heroku inspired workflow.

Once you have your Deis cluster up you might even want to sidestep it entirely and run Docker containers directly on your CoreOS cluster.

Deis can be used with Vagrant and VirtualBox and it can also deploy to multiple clouds (EC2, Rackspace, Digital Ocean, Bare Metal (e.g. Kimsufi should be possible http://bit.ly/1t2PPXB). I've been playing around with it and it looks great so far.