Docker is an open source product supporting the creation, management and deployment of containers. Containers provide an isolated process execution environment in a manner that is more lightweight than that afforded by virtual machines. Docker has, since its public release in 2013, developed to the point where now it is a compelling solution for any distributed application—simulations built on the High Level Architecture included. This paper provides an overview of Docker and how it can be used in support of deploying and running HLA federations. Much of Docker can be used as is to provide real benefit in support of the management of HLA federations. However, in several cases, greater benefit can be achieved through adapting HLA federations and federates to better support the Docker concept. These guidelines are enunciated throughout the discussion covering topics including building Docker images for federates, managing federate configuration files with Docker Volumes, using Docker Networking to connect the federation, exposing federate GUIs from containers to the user, and easing federation startup across multiple hosts using Docker Compose and Docker Swarm.