Modern microservices applications span multiple containers, and sometimes a single app may use thousands of containers. When operating at this scale, you need a container orchestration tool to manage all of those containers. Managing them by hand is simply not feasible.
This is where Kubernetes comes in. Kubernetes manages Docker containers that are used to package applications at scale. Since its launch in 2014, Kubernetes has enjoyed widespread adoption within the container ecosystem. It is fast becoming the de facto tool for orchestrating containers at scale.
What are the reasons for the meteoric rise of Kubernetes, and what are the factors that will shape its future? Let’s take a look by examining the major milestones in Kubernetes’ history.
Milestone 1: Kubernetes 1.0 Released
V1.0 of Kubernetes was released in 2015. (The 2014 releases of Kubernetes were beta versions.) V1.0 brought many key features like DNS, load balancing, scaling, and application-level health checking. Importantly, it allowed you to group your container clusters into pods for better management. This is one feature that separates Kubernetes from the rest of the pack.
The most prominent concern around Kubernetes back then was whether Kubernetes was production-ready. Docker itself was barely a year old, and the container ecosystem was highly nascent. Google has emphasized that prominent organizations like Box and Ebay use Kubernetes in production, and since then, many organizations have come out flaunting their use of the tool in their production environments.
Another concern has been Kubernetes’ steep learning curve. Designed at Google before the advent of Docker, it doesn’t follow the Docker CLI, API, Docker Compose, or YAML definitions. You need to manage containers using Kubernetes’ opinionated methods. However, many organizations find this worth the effort, considering the huge upside of having the most capable and open container orchestrator available today, and being able to confidently scale to thousands of containers.
Milestone 2: Google hands Kubernetes over to the CNCF
Quickly get started with Rancher and Kubernetes following the step-by-step instructions in the latest release of the Kubernetes eBook
Google’s open approach has been one of the key drivers for Kubernetes’ industry-wide adoption. While Kubernetes was developed at Google, once open-sourced, Google went all-out to integrate Kubernetes with every possible cloud vendor and containerization service— OpenStack, Azure, Mesosphere, and more.
Back in March 2016, Google gave complete control of Kubernetes over to the Cloud Native Computing Foundation (CNCF). Kubernetes was the first project to be accepted into the foundation. This is a big stamp of approval, showing how production-ready Kubernetes is. By making it part of the CNCF, Google has completely handed Kubernetes over to the container ecosystem to decide its future. This is further testament to Google’s neutral intentions when open-sourcing Kubernetes.
Milestone 3: Kubernetes Incubator seeds product development
Kubernetes Incubator is a GitHub repository that hosts promising new Kubernetes projects. Its goal is to bring consistency, and set standards to the efforts of developers trying to extend and innovate around Kubernetes. In Feb 2016, Helm became the first project to graduate from the Incubator. It is a package manager that packages applications as Kubernetes charts. Helm, along with Dashboard, has been integrated with Rancher as of v1.4.
Other interesting Kubernetes Incubator projects include Kompose, which moves Docker Compose files over to Kubernetes, and kube-aws, a tool to manage Kubernetes clusters on AWS. These projects are bridging the gap between Kubernetes and the rest of the container ecosystem. As Kubernetes gains mainstream adoption, these tools will grow in importance, and some may even become part of the main Kubernetes platform.
Kubernetes is evolving at a rapid pace. It recently reached GA on Azure Container Service. To mark the occasion, Kubernetes co-founder Brendan Burns wrote a thought-provoking piece on how Kubernetes will change the PaaS landscape. He sees industry-specific PaaS platforms emerging because of how easy Kubernetes makes building a PaaS system on top of container infrastructure. Beyond PaaS, there are even FaaS (function as a service) platforms like Fission and funktion being built with Kubernetes. This way, Kubernetes is not just powering applications, but enabling applications which can help create other powerful applications.
Kubernetes is still in its early days. As it matures, it will give rise to a growing ecosystem of managed Kubernetes service providers. This is critical to the adoption of Kubernetes in enterprises. While Kubernetes has shown explosive growth in the first three years of its existence, despite the lack of tooling and consensus around it, the next three years and more will be marked by a maturing of both the tool itself, and the ecosystem that supports it.
Another way Kubernetes helps the container ecosystem evolve faster is through the healthy competition it gives Docker Swarm. Despite Docker’s decision to bake Swarm into the Docker platform by default, the move has not slowed down Kubernetes’ growth. In fact, it’s becoming even more clear now that the industry is rallying around Kubernetes as it prefers a more open and highly scalable option to Docker’s Swarm. Kubernetes is one of the most active projects on Github, and it enjoys strong support from every corner of the industry. The strong consensus will see it become the leading container orchestrator in 2017 and beyond.
Twain began his career at Google, where, among other things, he was involved in technical support for the AdWords team. His work involved reviewing stack traces, resolving issues affecting both customers and the Support team, and handling escalations. Later, he built branded social media applications and automation scripts to help startups better manage their marketing operations. Today, as a technology journalist, he helps IT magazines and startups change the way teams build and ship applications.