Docker is a container-based technology created in 2013 by Docker, Inc. Container technology is not new, and has been around for some time on Unix OS, with chroot created in 1982, Solaris Zones in 2004, and WPAR available on AIX or OS400 systems (although WPAR is more of a virtualization technology than a container). Later, two important features were integrated on Linux: namespaces, which isolate OS function names, and cgroups, a collection of processes that are bound by configuration and resource limits. These new features gave birth to Linux containers, so why use Docker?
Mainly, because Docker made configuration definitions simple. Using a very easy-to-write Dockerfile, you can describe how to provision your container and create a new image with it. Each Dockerfile line will create a new FS layer using UnionFS, which makes changes very quick to apply, and it&apos...
