So, we’ve defined a basic container: It’s a lightweight distributed app that runs on a compatible Linux OS. It’s grown somewhat more confusing via the emergence of Docker, both as a company and an open-source project, which provides a management platform as well as a specific runtime and OS system for Linux containers.
But why are containers suddenly hot now? It’s been interesting to watch how a somewhat mysterious and wonky technology such as containers developed slowly for more than decade, originating in the open source software community, and then suddenly took off.
From Solaris to Docker
Early versions of the container concept included FreeBSD Jails and Oracle Solaris “Zones.” As mentioned, Google took major steps with container technology beginning around 2006 and developed Kubernetes. Docker was first introduced as an open source environment for building containerized microservices in 2013.
Perhaps the table was set for container technology with virtualization and cloud. Now that server virtualization has penetrated the market and many large companies are comfortable building applications in the cloud, container technology makes sense. Because containers are another form of virtualization, some IT experts are looking at the technology in cases in which it is more efficient than VMs – for example, it’s more efficient to run many instances of software on a single OS.