I've been able to use cgroups and net namespaces for years.
It's isn't obvious to me what Docker does that we haven't been able to do for some time now.
It's isn't obvious to me what Docker does that we haven't been able to do for some time now.
Since it isn't obvious to your, Docker and friends also have an entire content management system (pulling, pushing, tagging images and layers) as well as a build system.