Orchestration is a tough, holy grail domain. Remember the hype about service orchestration? Orchestration requires defining atomic units, dependencies, and interaction rules. Recent advancements in containerization are good, yet network dependencies need to be read from the docker configuration file. Also, docker provides 'links' to define relationships between containers, yet the links are not readily externalized outside the host machine. Also, docker by itself does not scale across multiple host machines, nor define what is inside the container.
A PaaS extending docker with enterprise-ready orchestration and application lifecycle management capabilities is required.