Why is Kubernetes getting so popular?

Introduction to Kubernetes:

Kubernetes is about six years old, and over the last two years, it has risen in popularity to consistently be one of the most loved platforms. This year, it comes in as the the number three most loved platform. If you haven’t heard about Kubernetes yet, it’s a platform that allows you to run and orchestrate container workloads.

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.

Going back in time

Let's take a look at why Kubernetes is so useful by going back in time.

Traditional deployment era: Early on, organizations ran applications on physical servers. There was no way to define resource boundaries for applications in a physical server, and this caused resource allocation issues. For example, if multiple applications run on a physical server, there can be instances where one application would take up most of the resources, and as a result, the other applications would underperform. A solution for this would be to run each application on a different physical server. But this did not scale as resources were underutilized, and it was expensive for organizations to maintain many physical servers.

Virtualized deployment era: As a solution, virtualization was introduced. It allows you to run multiple Virtual Machines (VMs) on a single physical server's CPU. Virtualization allows applications to be isolated between VMs and provides a level of security as the information of one application cannot be freely accessed by another application.

Virtualization allows better utilization of resources in a physical server and allows better scalability because an application can be added or updated easily, reduces hardware costs, and much more. With virtualization you can present a set of physical resources as a cluster of disposable virtual machines.

Each VM is a full machine running all the components, including its own operating system, on top of the virtualized hardware.

Container deployment era: Containers are similar to VMs, but they have relaxed isolation properties to share the Operating System (OS) among the applications. Therefore, containers are considered lightweight. Similar to a VM, a container has its own filesystem, share of CPU, memory, process space, and more. As they are decoupled from the underlying infrastructure, they are portable across clouds and OS distributions.

Why you need Kubernetes and what it can do?

Containers are a good way to bundle and run your applications. In a production environment, you need to manage the containers that run the applications and ensure that there is no downtime. For example, if a container goes down, another container needs to start. Wouldn't it be easier if this behavior was handled by a system?

That's how Kubernetes comes to the rescue! Kubernetes provides you with a framework to run distributed systems resiliently. It takes care of scaling and failover for your application, provides deployment patterns, and more. For example, Kubernetes can easily manage a canary deployment for your system.

Kubernetes provides you with:

• Service discovery and load balancing: Kubernetes can expose a container using the DNS name or using their own IP address. If traffic to a container is high, Kubernetes is able to load balance and distribute the network traffic so that the deployment is stable.
• Storage orchestration: Kubernetes allows you to automatically mount a storage system of your choice, such as local storages, public cloud providers, and more.
• Automated rollouts and rollbacks: You can describe the desired state for your deployed containers using Kubernetes, and it can change the actual state to the desired state at a controlled rate. For example, you can automate Kubernetes to create new containers for your deployment, remove existing containers and adopt all their resources to the new container.
• Automatic bin packing :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.
• Self-healing: Kubernetes restarts containers that fail, replaces containers, kills containers that don't respond to your user-defined health check, and doesn't advertise them to clients until they are ready to serve.
• Secret and configuration management: Kubernetes lets you store and manage sensitive information, such as passwords, OAuth tokens, and SSH keys. You can deploy and update secrets and application configuration without rebuilding your container images, and without exposing secrets in your stack configuration.

Kubernetes architecture and how it works?

Kubernetes evolved from the code that Google used to manage its data centers at scale with the “Borg” platform. AWS introduced elastic web server frameworks to the public with the launch of the EC2 platform. Kubernetes allows companies to orchestrate containers like EC2 but using open source code. Google, AWS, Azure, and the other major public cloud hosts all offer Kubernetes support for cloud web server orchestration. Customers can use Kubernetes for complete data center outsourcing, web/mobile applications, SaaS support, cloud web hosting, or high-performance computing.

Kubernetes Use Cases 

CASE STUDY:adidas

Challenge: In recent years, the adidas team was happy with its software choices from a technology perspective—but accessing all of the tools was a problem. For instance, "just to get a developer VM, you had to send a request form, give the purpose, give the title of the project, who's responsible, give the internal cost center a call so that they can do recharges," says Daniel Eichten, Senior Director of Platform Engineering. "The best case is you got your machine in half an hour. Worst case is half a week or sometimes even a week."

Solution:To improve the process, "we started from the developer point of view," and looked for ways to shorten the time it took to get a project up and running and into the adidas infrastructure, says Senior Director of Platform Engineering Fernando Cornago. They found the solution with containerization, agile development, continuous delivery, and a cloud native platform that includes Kubernetes and Prometheus.

Impact:Just six months after the project began, 100% of the adidas e-commerce site was running on Kubernetes. Load time for the e-commerce site was reduced by half. Releases went from every 4-6 weeks to 3-4 times a day. With 4,000 pods, 200 nodes, and 80,000 builds per month, adidas is now running 40% of its most critical, impactful systems on its cloud native platform.

CASE STUDY:Spotify

Challenge: Launched in 2008, the audio-streaming platform has grown to over 200 million monthly active users across the world. "Our goal is to empower creators and enable a really immersive listening experience for all of the consumers that we have today—and hopefully the consumers we'll have in the future," says Jai Chakrabarti, Director of Engineering, Infrastructure and Operations. An early adopter of microservices and Docker, Spotify had containerized microservices running across its fleet of VMs with a homegrown container orchestration system called Helios. By late 2017, it became clear that "having a small team working on the features was just not as efficient as adopting something that was supported by a much bigger community," he says.

Solution: "We saw the amazing community that had grown up around Kubernetes, and we wanted to be part of that," says Chakrabarti. Kubernetes was more feature-rich than Helios. Plus, "we wanted to benefit from added velocity and reduced cost, and also align with the rest of the industry on best practices and tools." At the same time, the team wanted to contribute its expertise and influence in the flourishing Kubernetes community. The migration, which would happen in parallel with Helios running, could go smoothly because "Kubernetes fit very nicely as a complement and now as a replacement to Helios," says Chakrabarti.

Impact:The team spent much of 2018 addressing the core technology issues required for a migration, which started late that year and is a big focus for 2019. "A small percentage of our fleet has been migrated to Kubernetes, and some of the things that we've heard from our internal teams are that they have less of a need to focus on manual capacity provisioning and more time to focus on delivering features for Spotify," says Chakrabarti. The biggest service currently running on Kubernetes takes about 10 million requests per second as an aggregate service and benefits greatly from autoscaling, says Site Reliability Engineer James Wen. Plus, he adds, "Before, teams would have to wait for an hour to create a new service and get an operational host to run it in production, but with Kubernetes, they can do that on the order of seconds and minutes." In addition, with Kubernetes's bin-packing and multi-tenancy capabilities, CPU utilization has improved on average two- to threefold.

CASE STUDY: box

Challenge:Founded in 2005, the enterprise content management company allows its more than 50 million users to manage content in the cloud. Box was built primarily with bare metal inside the company's own data centers, with a monolithic PHP code base. As the company was expanding globally, it needed to focus on "how we run our workload across many different cloud infrastructures from bare metal to public cloud," says Sam Ghods, Cofounder and Services Architect of Box. "It's been a huge challenge because of different clouds, especially bare metal, have very different interfaces."

Solution:Over the past couple of years, Box has been decomposing its infrastructure into microservices, and became an early adopter of, as well as contributor to, Kubernetes container orchestration. Kubernetes, Ghods says, has allowed Box's developers to "target a universal set of concepts that are portable across all clouds."

Impact:"Before Kubernetes," Ghods says, "our infrastructure was so antiquated it was taking us more than six months to deploy a new microservice. Today, a new microservice takes less than five days to deploy. And we're working on getting it to an hour."

Conclusion:

While Kubernetes’ architecture and set of internal components can at first seem daunting, their power, flexibility, and robust feature set are unparalleled in the open-source world. By understanding how the basic building blocks fit together, you can begin to design systems that fully leverage the capabilities of the platform to run and manage your workloads at scale. Since the introduction of Kubernetes, you can safely say that almost all of the other orchestrators are either irrelevant or have taken a back seat to Kubernetes. Just over few years, every major public cloud provider has a managed Kubernetes service or is in the process of developing one.