Starting A Digital Ocean Instance From Docker Machine

My buddy Dusty recently asked me how to set up a Digital Ocean cloud instance for RStudio using a Docker image. Below is the information he needed, but captured here for future travelers. Most people who are considering using Docker understand that Docker allows setting up something akin to a virtual machine on their local computer. What’s less widely appreciated among non dev-ops folks is that Docker comes with a tool called docker-machine that allows setting up a Docker virtual system on a remote server.