Description of problem:
~ $ sudo service docker-registry start                 
[sudo] password for misc: 
Redirecting to /bin/systemctl start  docker-registry.service
Failed to start docker-registry.service: Unit redis.service failed to load: No such file or directory.

There is no hard requirement for redis.service to be on the same system, and I am not even sure redis is required for anything. SO this requirement should be relaxed.