What is Kubernetes and case study of Kubernetes

What is 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.

OS Provisioning methods( previous time) :

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

There are mainly 4 methods for os provisioning but here I discuss only local system methods.

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.

Containers have become popular because they provide extra benefits, such as:

• Agile application creation and deployment: increased ease and efficiency of container image creation compared to VM image use.
• Continuous development, integration, and deployment: provides for reliable and frequent container image build and deployment with quick and easy rollbacks (due to image immutability).
• Dev and Ops separation of concerns: create application container images at build/release time rather than deployment time, thereby decoupling applications from infrastructure.
• Observability not only surfaces OS-level information and metrics, but also application health and other signals.
• Environmental consistency across development, testing, and production: Runs the same on a laptop as it does in the cloud.
• Cloud and OS distribution portability: Runs on Ubuntu, RHEL, CoreOS, on-premises, on major public clouds, and anywhere else.
• Application-centric management: Raises the level of abstraction from running an OS on virtual hardware to running an application on an OS using logical resources.
• Loosely coupled, distributed, elastic, liberated micro-services: applications are broken into smaller, independent pieces and can be deployed and managed dynamically – not a monolithic stack running on one big single-purpose machine.
• Resource isolation: predictable application performance.
• Resource utilization: high efficiency and density.

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.

CASE STUDY of Nokia:

(Enabling 5G and DevOps at a Telecom Company with Kubernetes)

Challenge

Nokia's core business is building telecom networks end-to-end; its main products are related to the infrastructure, such as antennas, switching equipment, and routing equipment. "As telecom vendors, we have to deliver our software to several telecom operators and put the software into their infrastructure, and each of the operators have a bit different infrastructure," says Gergely Csatari, Senior Open Source Engineer. "There are operators who are running on bare metal. There are operators who are running on virtual machines. There are operators who are running on VMware Cloud and OpenStack Cloud. We want to run the same product on all of these different infrastructures without changing the product itself."

Solution

The company decided that moving to cloud native technologies would allow teams to have infrastructure-agnostic behavior in their products. Teams at Nokia began experimenting with Kubernetes in pre-1.0 versions. "The simplicity of the label-based scheduling of Kubernetes was a sign that showed us this architecture will scale, will be stable, and will be good for our purposes," says Csatari. The first Kubernetes-based product, the Nokia Telephony Application Server, went live in early 2018. "Now, all the products are doing some kind of re-architecture work, and they're moving to Kubernetes."

Impact

Kubernetes has enabled Nokia's foray into 5G. "When you develop something that is part of the operator's infrastructure, you have to develop it for the future, and Kubernetes and containers are the forward-looking technologies," says Csatari. The teams using Kubernetes are already seeing clear benefits. "By separating the infrastructure and the application layer, we have less dependencies in the system, which means that it's easier to implement features in the application layer," says Csatari. And because teams can test the exact same binary artifact independently of the target execution environment, "we find more errors in early phases of the testing, and we do not need to run the same tests on different target environments, like VMware, OpenStack, or bare metal," he adds. As a result, "we save several hundred hours in every release."

Nokia was the first name in mobile phones when they were becoming ubiquitous in the late 1990s and early 2000s. But by 2014, the company had sold off its mobile device division and was focusing its core business not on the handhelds used for calls, but on the networks.

Today, Nokia is building telecom networks end-to-end—from antennas to switching and routing equipment—serving operators in more than 120 countries. "As telecom vendors, we have to deliver our software to several telecom operators and put the software into their infrastructure, and each of the operators have a bit different infrastructure," says Gergely Csatari, Senior Open Source Engineer at Nokia. "There are operators who are running on bare metal. There are operators who are running on virtual machines. There are operators who are running on VMware Cloud and OpenStack Cloud. We want to run the same product on all of these different infrastructures without changing the product itself."

Looking for a way to allow its teams to build products with infrastructure-agnostic behavior, the company decided to embrace containerization, Kubernetes, and other cloud native technologies, a move that is being made across the telecom industry. Since early 2018, "when people are picking up their phones and making a call on Nokia networks, they are creating containers in the background with Kubernetes," says Csatari. "Now, all the products are doing some kind of re-architecture work, and they're moving to Kubernetes."

Nokia's cloud native journey began about two years ago, when Csatari's team was building the company's Telephony Application Server (TAS). "We wanted to have a service execution engine in the product, which was a totally separate function from all other parts," he says. "There, we had the possibility to think about new architectures and new tools that we could use. We created this particular product based on Kubernetes, and we liked the work, so we started to talk about cloud native and containers and all of these things. We did a very extensive research of different container orchestration tools. We knew that we have some, let's say, strange or different requirements because of the special environment that our software is running on."

For one thing, Nokia's software serves millions of people, and is required to have the carrier-grade "five nines" availability: to be up 99.999% of the time. "If you turn it to minutes, this means we're allowed to have only 10 minutes of downtime in a whole year," says Csatari. "Downtime here means that you are not able to serve the person to full capacity, which means that we cannot fail. This includes software upgrades, everything, because when you call 911, you're using our software, and you expect that it will work."

That meant that they needed to be able to set affinity and anti-affinity rules in their orchestration tools. "You cannot put all of the functions to the same physical host because physical hosts are failing," Csatari explains. "If you fail with one physical host, then you lose all of the core processing processes. Then there are no calls going through. So we have to divide them among the different physical hosts. At that time, only Kubernetes was able to provide these features. The simplicity of the label-based scheduling of Kubernetes was a sign that showed us this architecture will scale, will be stable, and will be good for our purposes."

The TAS went live in early 2018, and now Kubernetes is also enabling Nokia's foray into 5G. The company is introducing microservices architecture and Kubernetes while adding 5G features to existing products. And all new 5G product development will be on top of Kubernetes. "When you develop something that is part of the operator's infrastructure, you have to develop it for the future, and Kubernetes and containers are the forward-looking technologies," says Csatari.

There have been real time savings thanks to Kubernetes. "By separating the infrastructure and the application layer, we have less dependencies in the system, which means that it's easier to implement features in the application layer," says Csatari. Because teams can test the exact same binary artifact independently of the target execution environment, "we find more errors in early phases of the testing, and we do not need to run the same tests on different target environments, like VMware, OpenStack or bare metal," he adds. As a result, "we save several hundred hours in every release."

Moving from Nokia's legacy cluster management system, which had been built in-house more than thirty years ago, to a Kubernetes platform also meant that "we started using Linux as a base operating system, so we just opened the window to all of these open source projects instead of implementing everything in house," says Csatari. (From CNCF's ecosystem, the team is already using Helm, gRPC, CNI, Prometheus and Envoy and plans to implement CoreDNS.) "Our engineers can focus more on the application level, which is actually the thing what we are selling, and not on the infrastructure level. For us, the most important thing about Kubernetes is it allows us to focus on value creation of our business."

The company has a long-term goal of moving the entire product portfolio into the Kubernetes platform. To that end, Nokia teams are working together with other companies to add the features needed to use Kubernetes with the real-time, nanosecond-sensitive applications close to the edge of the radio network.

And the CNCF community is proving to be a great forum for that collaboration. "I had some discussions at KubeCon with people from the networking SIG and the resource management working group, to work together on our requirements, and that's very exciting for me and my colleagues," says Csatari. "Previously, everybody had the same problem, but everybody just did it in his own, and now we are trying to solve the same problem together."

Perhaps the biggest impact that Kubernetes is having on Nokia, Csatari believes, is that people are starting to think about how a telecom company can do DevOps. "We are building a DevOps pipeline, which reaches from the actual developer to the customers, and thinking about new ways how can we digitally deliver our software to our customers and get feedback from the customers right to the engineers," he says. "This is something that will fundamentally change how telecom companies are delivering software, and how quickly can we develop new features. This is because of the usage of containers and, of course, the usage of Kubernetes."