Kubernetes, often abbreviated as K8s, is an open-source platform designed to automate the deployment, scaling, and management of containerized applications. It groups containers that make up an application into logical units for easy management and discovery. Kubernetes is a key player in the world of DevOps, as it provides a robust foundation for cloud-native applications, allowing for rapid deployment and scalability.
As a part of the DevOps glossary, understanding Kubernetes is crucial for anyone involved in the development, deployment, and maintenance of software. This article will delve into the depths of Kubernetes, exploring its definition, history, use cases, and specific examples to provide a comprehensive understanding of this essential DevOps tool.
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.
Key Components of Kubernetes
The Kubernetes system is composed of a set of independent components that run as separate processes on the nodes they manage. The key components include the Kubernetes Master, Nodes, Pods, and Services.
The Kubernetes Master is the main controlling unit of the cluster, managing its workload and directing communication across the system. The Nodes are the workers that run applications. A Node may be a VM or a physical machine, depending on the cluster. Each Node is managed by the Master. A Node can have multiple pods, and the Kubernetes master automatically handles scheduling the pods across the Nodes in the cluster. The Pods are the smallest and simplest units in the Kubernetes object model that you create or deploy. A Pod represents a running process on your cluster.
How Kubernetes Works
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 interfaces and platform primitives for defining, deploying, and managing your applications. You provide Kubernetes with a cluster of nodes that it can use to run containerized tasks. You tell Kubernetes how much CPU and memory (RAM) each container needs. Kubernetes can fit containers onto your nodes to make the best use of your resources.
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 Kubernetes project was open-sourced by Google in 2014, and its development has been heavily influenced by the community ever since. The project is now maintained by the Cloud Native Computing Foundation (CNCF), which is a part of the larger Linux Foundation. Kubernetes has become the standard for container orchestration and has been adopted by major cloud providers, including AWS, Google Cloud, and Microsoft Azure.
The Role of the Cloud Native Computing Foundation (CNCF)
The Cloud Native Computing Foundation (CNCF) is a project of The Linux Foundation, which itself is a nonprofit technology consortium founded in 2000. The CNCF was founded in 2015 with the goal of advancing the state of the art for building cloud native applications and services. The CNCF hosts a variety of projects, including Kubernetes, Prometheus, and Envoy, among others.
The CNCF plays a crucial role in the Kubernetes project. It provides a neutral home where various stakeholders can collaborate and make decisions about the project's future. The CNCF also provides resources for the development and promotion of Kubernetes, including event organization, marketing, and more.
Use Cases of Kubernetes
Kubernetes is used in a variety of scenarios, thanks to its flexibility, scalability, and robustness. It is often used in cloud environments, but it can also be used in on-premises and hybrid environments. Some of the most common use cases for Kubernetes include managing microservices, supporting modern, cloud-native applications, and facilitating DevOps practices.
Microservices architecture is a design approach to build a single application as a set of small services. Each service runs in its own process and communicates with other services via a well-defined API. Kubernetes provides a platform to easily deploy, scale, and manage these microservices.
Supporting Cloud-Native Applications
Cloud-native applications are designed to take full advantage of cloud computing frameworks. They are built with services packaged in containers, deployed as microservices, and managed on elastic infrastructure through agile DevOps processes and continuous delivery workflows. Kubernetes provides the orchestration and management capabilities needed to deploy and run these applications.
With Kubernetes, developers can make a simple command to create, scale, or update thousands of container instances. Kubernetes handles the distribution and scheduling of these containers across a cluster of servers. It also handles service discovery and load balancing, and it can automatically restart failed containers, roll out updates and changes to containers, and secure inter-service communication.
Facilitating DevOps Practices
Kubernetes plays a crucial role in facilitating DevOps practices such as continuous integration/continuous delivery (CI/CD), infrastructure as code (IaC), and monitoring and logging. With Kubernetes, teams can automate the process of building, testing, and deploying applications, making it easier to maintain high standards of quality and reliability.
Infrastructure as Code (IaC) is a key DevOps practice that involves managing and provisioning computing infrastructure with machine-readable definition files, rather than physical hardware configuration or interactive configuration tools. Kubernetes supports IaC through its declarative object configuration model. With Kubernetes, you can define your applications and services as YAML or JSON objects, which can be version controlled and managed just like application code.
Examples of Kubernetes in Action
Many organizations have adopted Kubernetes to manage their containerized workloads and services. For example, Spotify, the popular music streaming service, migrated its backend services to Kubernetes to take advantage of its automation and scalability features. The New York Times also uses Kubernetes to manage its microservices architecture, which supports its digital and print publication.
Another example is Pokemon Go, a popular mobile game, which used Kubernetes to manage its backend infrastructure. At the height of its popularity, the game was serving millions of players around the world, and Kubernetes helped to ensure that its services could scale to meet demand.
Spotify's Migration to Kubernetes
Spotify, the popular music streaming service, migrated its backend services to Kubernetes to take advantage of its automation and scalability features. The migration process involved moving over 150 microservices from an in-house deployment platform to Kubernetes. The result was a more robust, scalable, and efficient system that could better support Spotify's growing user base.
The migration to Kubernetes also helped Spotify's development teams become more productive. With Kubernetes, they could easily create, update, and manage their services without having to worry about the underlying infrastructure. This allowed them to focus more on developing features and improving the user experience.
The New York Times' Use of Kubernetes
The New York Times, one of the largest and most respected newspapers in the world, uses Kubernetes to manage its microservices architecture. This architecture supports both its digital and print publication, which requires a high level of reliability and scalability.
With Kubernetes, The New York Times can easily scale its services to meet demand, whether it's a surge in traffic due to a breaking news story or the daily spike in traffic that occurs when the digital edition is published. Kubernetes also provides the newspaper with a robust platform for continuous integration and delivery, allowing it to regularly update its services with new features and improvements.
Conclusion
In conclusion, Kubernetes is a powerful tool for managing containerized applications at scale. Its flexibility, robustness, and wide community support make it a key player in the world of DevOps. Whether you're managing a small application with a few services or a large system with hundreds of microservices, Kubernetes provides the tools and abstractions you need to deploy, scale, and manage your workloads efficiently and reliably.
Understanding Kubernetes is crucial for anyone involved in the development, deployment, and maintenance of software. As more organizations adopt cloud-native architectures and DevOps practices, the demand for professionals with Kubernetes skills is likely to continue growing. By learning about Kubernetes and gaining hands-on experience with it, you can open up new opportunities for your career and contribute to the future of software development.