Postgres-XL Docker is a Docker image source for Postgres-XL, the scalable open-source PostgreSQL-based database cluster. The images are based on CentOS. The images allow for arbitrary database cluster topologies, allowing GTM, GTM Proxy, Coordinator, and Datanode nodes to be created and added as desired. Each service runs in its own container, communicating over a backend network. Coordinator nodes also connect to a frontend network.