In my testing of the new MetroAE Croxley container deployment on CentOS 7, I have found the following installation instructions for Docker CE to be accurate and reliable:
Docker Community Edition (CE) is ideal for individual developers and small teams looking to get started with Docker and experimenting with container-based apps. You can also choose Docker EE. Docker Enterprise Edition (EE) is designed for enterprise development and IT teams who build, ship, and run business critical applications in production at scale. Generally speaking, Docker CE is sufficient for MetroAE.