  We describe preliminary investigations of using Docker for the deployment and
testing of astronomy software. Docker is a relatively new containerisation
technology that is developing rapidly and being adopted across a range of
domains. It is based upon virtualization at operating system level, which
presents many advantages in comparison to the more traditional hardware
virtualization that underpins most cloud computing infrastructure today. A
particular strength of Docker is its simple format for describing and managing
software containers, which has benefits for software developers, system
administrators and end users.
  We report on our experiences from two projects -- a simple activity to
demonstrate how Docker works, and a more elaborate set of services that
demonstrates more of its capabilities and what they can achieve within an
astronomical context -- and include an account of how we solved problems
through interaction with Docker's very active open source development
community, which is currently the key to the most effective use of this
rapidly-changing technology.
