Kubernetes is a popular open source platform for container orchestration — that is, for the management of applications built out of multiple, largely self-contained runtimes called containers. Containers have become increasingly popular since the Docker containerization project launched in 2013, but large, distributed containerized applications can become increasingly difficult to coordinate. By making containerized applications dramatically easier to manage at scale, Kubernetes has become a key part of the container revolution.
What is container orchestration?
Containers support VM-like separation of concerns but with far less overhead and far greater flexibility. As a result, containers have reshaped the way people think about developing, deploying, and maintaining software. In a containerized architecture, the different services that constitute an application are packaged into separate containers and deployed across a cluster of physical or virtual machines. But this gives rise to the need for container orchestration—a tool that automates the deployment, management, scaling, networking, and availability of container-based applications.
What is Kubernetes?
Kubernetes is an open source project that has become one of the most popular container orchestration tools around; it allows you to deploy and manage multi-container applications at scale. While in practice Kubernetes is most often used with Docker, the most popular containerization platform, it can also work with any container system that conforms to the Open Container Initiative (OCI) standards for container image formats and runtimes. And because Kubernetes is open source, with relatively few restrictions on how it can be used, it can be used freely by anyone who wants to run containers, most anywhere they want to run them—on-premises, in the public cloud, or both.
Google and Kubernetes
Kubernetes began life as a project within Google. It’s a successor to—though not a direct descendent of—Google Borg, an earlier container management tool that Google used internally. Google open sourced Kubernetes in 2014, in part because the distributed microservices architectures that Kubernetes facilitates makes it easy to run applications in the cloud. Google sees the adoption of containers, microservices, and Kubernetes as potentially driving customers to its cloud services (although Kubernetes certainly works with Azure and AWS as well). Kubernetes is currently maintained by the Cloud Native Computing Foundation, which is itself under the umbrella of the Linux Foundation.