Kubernetes, also known as K8s, is an open-source platform designed to automate deploying, scaling, and operating application containers. With Kubernetes, you can quickly and efficiently respond to customer demand: Deploy your applications quickly and predictably. Scale your applications on the fly. Seamlessly roll out new features. Optimize use of your hardware by using only the resources you need.
Our journey into Kubernetes will cover its definition, explanation, history, use cases, and specific examples. By the end of this glossary entry, you should have a comprehensive understanding of Kubernetes and its role in DevOps.
Definition of Kubernetes
Kubernetes is a portable, extensible, open-source platform for managing containerized workloads and services, that facilitates both declarative configuration and automation. It has a large, rapidly growing ecosystem. Kubernetes services, support, and tools are widely available.
The name Kubernetes originates from Greek, meaning helmsman or pilot. Google open-sourced the Kubernetes project in 2014. Kubernetes combines over 15 years of Google's experience running production workloads at scale with best-of-breed ideas and practices from the community.
Components of Kubernetes
Kubernetes is made up of a set of independent, composable control processes that continuously drive the current state towards the provided desired state. It provides the platform to schedule and run containers on clusters of physical or virtual machines.
More specifically, it is used to manage microservices or containerized applications across a distributed cluster of nodes. There are multiple components in a Kubernetes cluster that interact with each other to deliver the platform's functionality.
Explanation of Kubernetes
Kubernetes provides a framework to run distributed systems resiliently. It takes care of scaling and failover for your applications, provides deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.
Kubernetes provides you with APIs to define your apps and services, and it can manage them for you using a desired state model. Kubernetes also provides primitives for service discovery and load balancing, storage orchestration, automated rollouts and rollbacks, secret and configuration management, and more.
How Kubernetes Works
Kubernetes works by managing a cluster of nodes, where each node runs containers. Kubernetes provides the orchestration and management capabilities to create and manage the nodes and containers. It does this by providing a control plane (the master node) that users and system components interact with to manage the state of the cluster.
The control plane makes decisions about what runs on the nodes, including scheduling decisions, responding to changes in workload, and maintaining the desired state of the applications. The nodes are where the workloads (containers and pods) run. Kubernetes runs your workload by placing containers into Pods to run on Nodes.
History of Kubernetes
Kubernetes was originally developed and designed by engineers at Google. Google was one of the early contributors to Linux container technology and has talked publicly about how everything at Google runs in containers. (This is the technology behind Google’s cloud services.)
Google generates more than 2 billion container deployments a week—all powered by an internal platform: Borg. Borg was the predecessor to Kubernetes and the lessons learned from developing Borg over the years became the primary influence behind much of the Kubernetes technology.
The Birth of Kubernetes
The first version of Kubernetes was announced by Google in mid-2014. Its development and design was heavily influenced by Google's Borg system, and the lessons learned from Borg over the years became the primary influence behind much of the Kubernetes technology.
The process of developing Kubernetes was opened up to the public community, and it officially became an open-source project. Since then, Kubernetes has become the standard system for container orchestration and is maintained by the Cloud Native Computing Foundation (CNCF).
Use Cases of Kubernetes
Kubernetes is used in many modern environments. Because it is open-source, it can be used freely by anyone. Kubernetes is used by teams of all sizes, from small startups to big corporations, and by developers across all sectors of the industry.
Some common use cases of Kubernetes include managing microservices, batch processing, hosting cloud-native applications, and data processing. It's also used in research computing environments, and anywhere else that benefits from container-based infrastructure.
Examples of Kubernetes Use
One specific example of Kubernetes in use is at the New York Times. Their content management system, which handles both news stories and the homepage layout, runs on a Kubernetes cluster. The team at the New York Times uses Kubernetes to ensure that their system is always available, even when traffic spikes during major news events.
Another example is at Spotify. The music streaming service uses Kubernetes to ensure that its development team can easily package and ship code. This allows them to ensure that their 100 million users always have access to the music they want to listen to.
Conclusion
Understanding Kubernetes is essential for modern software development, particularly in the DevOps field. Its ability to manage complex, containerized applications makes it a crucial tool for developers and system administrators alike.
Whether you're a developer looking to deploy your app, an operator maintaining a production system, or a CIO looking at your overall IT strategy, Kubernetes has something to offer you. It's a robust, flexible platform that has already reshaped the tech industry and will continue to do so in the future.