Docker

Container technology is one of the fastest growing technologies today, and Docker is leading it. Docker is an open source project and it was launched in 2013. 10,000 developers tried it after its interactive tutorial launched in August 2013. It was downloaded 2.75 million times by the time of the launch of its 1.0 release in June 2013. Many large companies have signed a partnership agreement with Docker, such as Microsoft, Red Hat, HP, OpenStack, and service providers such as AWS, IBM, and Google.

As we mentioned earlier, Docker also makes use of Linux kernel features, such as cgroups and namespaces, to ensure resource isolation and the packaging of the application with its dependencies. This packaging of dependencies enables an application to run as expected across different Linux OSes/distributions, supporting a level of portability. Furthermore, this portability allows developers to develop an application in any language and then easily deploy it from a laptop to a test or production server.

Containers are comprised of just the application and its dependencies, including the basic OS. This makes the application lightweight and efficient in terms of resource utilization. Developers and system administrators are interested in a container's portability and efficient resource utilization.

Everything in a Docker container executes natively on the host and uses the host kernel directly. Each container has its own user namespace.