There are a few options for using Docker in production. At the simplest (in terms of least infrastructure at least) you could just have a VM somewhere running D

There are a few options for using Docker in production. At the simplest (in terms of least infrastructure at least) you could just have a VM somewhere running Docker, and use docker-compose or similar to bring everything up as you would in development. In the middle you have Amazon Elastic Beanstalk which can take a Docker image and deploy it with minimal hassle, and at the other end of the spectrum you have Kubernetes/Mesosphere/Amazon ECS to allow distributing containers across a cluster of machines. Except for isolation there's no particular need to run one container per server - while there is a bit of overhead to running in containers my experience is that its offset by being able to run multiple services which don't require a lot of resources alongside each other on one server.