Kubernetes is a term that most people generally don’t understand or know about. The name came to life in 2015 and is so popular now that some people believe that it might take a toll on virtual machines that were considered a revolutionary concept once. But this is the beauty of life, as well as technology, that new and better things replace the old ones.
Why Kubernetes is used, is not a question, which can be addressed in isolation. You must have an idea about the past technology, what Kubernetes has to offer, and why people use and love it so much. By people, it means developers and testing teams as well as Google, which is the biggest user of Kubernetes.
This article discusses everything about Kubernetes, the technologies and terminology involved, why containers are so popular, and why Kubernetes is used. Stay glued.
What is Kubernetes?
Before you dive right into the definition, let’s understand the need and mechanism of Kubernetes.
Earlier, it was complicated to share the resources while developing and testing applications during the development phase. Installing numerous physical servers was a costly affair and, in most cases, not feasible at all. Some applications used to eat up most of the CPU memory and storage, making other applications underperform.
Virtual machines were quite an invention at that time. These were created independently of the hardware, i.e., you could run several VMs on a single computer. The resources were pre-allocated so that every application has a predetermined quota for the resource usage.
Containers, on the other hand, were born under the Linux kernel process isolation to work with complete isolation with a set of resources. With the advent of Docker in 2013, the use of containers became more popular.
Each container is repeatable and contains standardized dependencies so that it behaves the same every time it runs, irrespective of the OS it is being run on. Now in order to understand more about the container mechanism, i.e. the Cluster Architecture, and Kubernetes process, you must know a few important definitions, detailed as follows.
Some Important Definitions
Pods – The most basic deployable object in Kubernetes is a Pod. It may contain a single container or multiple containers. You can understand a pod by considering it as a wrapper around one or multiple containers.
Containers – A container is independent of the operating system, which makes it easily accessible across different platforms. It contains an application, all its dependencies, its default value settings, codes, and any runtime that it requires to run.
It is possible to make code changes to any running container, but a new image is to be created, and the container needs to be restarted with the new image.
Cluster – A Kubernetes cluster is a group of nodes that run the containers. The cluster is divided into two parts; nodes and control planes. The nodes run the applications, and the Kubernetes control plane manages the nodes.
Deployment – A deployment is a set of pods that ensure that many pods are running to service the running application. It automatically closes the pods that are not being used.
Nodes – Nodes are the virtual or physical machines that run the containers.
Why Kubernetes?
Creating and managing virtual machines required configuration and cost. They need to be managed. The same applies to containers as well. They needed to be orchestrated for deployment, scheduling, and load balancing. Google has contributed greatly to the popularity of Kubernetes.
Kubernetes has derived its name from a Greek word that means pilot or sailing master; the one who holds the wheel. Kubernetes manages these containers by deploying them to clusters.
One of the main features of Kubernetes is that it is vendor-agnostic, i.e., it is developed by Google, which does not dominate it anymore, and several vendors are contributing to this largest open-source container management tool.
What is Kubernetes used for?
Now that you understand what Kubernetes is, next, you must understand why Kubernetes is used.
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Elimination of Infrastructural Boundaries
Earlier, the applications were dependent on their network architecture, the storage system, orchestration techniques, cloud service techniques, and whatnot. The infrastructure was a barrier, and crossing it meant more costs for the organization.
Platform-as-a-Service was a great initiative to overcome the problem, but the restrictions did not make things very helpful for the development teams.
In today’s era, there is a need to develop applications that can run across multiple platforms, multiple environments, irrespective of the operating systems, including private clouds, virtual clouds, public clouds, etc.
Kubernetes overcomes this problem through its infrastructure, which allows a containerized application to run in the same way irrespective of where it is being run.
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Deployment and Updation Made Easy
Saving time is the most important part of any process. Kubernetes have allowed the development and testing teams to collaborate and create an application without wasting time. Kubernetes Controller allows it to deploy and update the software on a scale. It simplifies various complex management tasks such as:
- Scaling – The deployments can be scaled in and out as and when needed.
- Time savings – A deployment can be paused and resumed whenever required, thereby saving time.
- Updating Pods – The deployed pods can be updated using newer versions. They can also be rolled back to earlier deployments if the newer version is not suitable.
- Visibility – It is possible to query completed, in-process, and failed deployments.
Kubernetes offers the freedom to run applications and supports a wide variety of workloads.
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Modular Approach
A pod contains one or more containers. Multiple containers in a pod run as a single application. Each container has a part of an application, and each pod contains containers on which the individual teams work for which they are held responsible. The dependencies are isolated, and the functions are divided by the team, which saves time.
By combining the containers in a pod, the functionalities are not jammed up to the full in a single container image. The containers in a pod share resources, namespace, and an IP address. These singular modules are integrated and orchestrated by Kubernetes, making the approach successful.
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A Path Towards The Future
Kubernetes is the future. There are several other orchestration tools that have emerged over the years. Docker and Mesos are in the market for a time longer than Kubernetes. There are Docker Swarm, Mesos with Marathon, HashiCorp’s Nomad, etc. Some of them are limited to containers, while others allow the deployment of any application.
The technologies and features are being copied, and new entrants are ready to set foot in the market. Still, Kubernetes is popular among them all due to its innovative idea, architecture and because it is open-source. It offers everything that modern application developers require.
Why is Kubernetes so Popular?
The increased use of cloud-native architectures has made the developers realize that Kubernetes is the best platform for deploying and managing containers. Leading reasons why developers are loving Kubernetes are:
- It saves money – Containers are very light-weight, and running them does not require as much memory and storage as virtual machines do. Thus, Kubernetes is cost-efficient as it requires fewer resources and hardware to perform desired functions.
- It saves time – Waiting for the resources to be freed up is something that is never faced by Kubernetes users. The infrastructure resources are pre-allocated, and you can request them whenever you need them. The hardware layer abstraction has changed how things work.
- It is cloud-agnostic – Using Azure, AWS, or GCP? Don’t worry. Kubernetes runs on all of them, and if you need to run it anywhere else, it will run. As it is independent of the infrastructure, it can run on any cloud platform you want.
Final Thoughts
Kubernetes is not just a container orchestration tool anymore. It is changing the way applications are developed nowadays. It has eliminated the system and infrastructure dependency and is gaining popularity with every passing day. This is the desire of every development team.