What is Kubernetes? | An Ultimate Guide 101


Kubernetes is a powerful and widely used open-source platform for managing containerized workloads and services. It is a portable and extensible platform that facilitates declarative configuration and automation. Its services, support, and tools are widely available and have a rapidly growing ecosystem.

The name Kubernetes originates from Greek, meaning helmsman or pilot, and the abbreviation K8s results from counting the eight letters between the “K” and the “s”. Google open-sourced the Kubernetes project in 2014, combining over 15 years of Google’s experience running production workloads at scale with best-of-breed ideas and practices from the community.

In this guide, we will take a closer look at why Kubernetes is so valuable by going back in time to understand the evolution of deployment. We will also explore why you need Kubernetes and what it can do for you.

Evolution of Deployment

Let’s start with a brief history lesson. In the early days of computing, organizations ran applications on physical servers. Unfortunately, there was no way to define resource boundaries for applications in a physical server, which caused resource allocation issues. For example, suppose multiple applications run on a physical server. In that case, there can be instances where one application would take up most of the resources, and as a result, the other applications would underperform.

To address this issue, virtualization was introduced, allowing you to run multiple Virtual Machines (VMs) on a single physical server’s CPU. As a result, virtualization allowed better utilization of resources in a physical server, reduced hardware costs, and enabled better scalability because an application could be added or updated easily.

Source: https://kubernetes.io/

However, virtualization still had its limitations. Each VM is a full machine running all the components, including its own operating system, on top of the virtualized hardware. This approach resulted in a large memory footprint, and VMs took longer to start up, slowing down application deployment and scaling.

Then came containerization. Containers are similar to VMs but 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 filesystem, share of CPU, memory, process space, and more. However, decoupled from the underlying infrastructure, they are portable across clouds and OS distributions.

Why Use Kubernetes?

Containers are an excellent way to bundle and run your applications but they require management. Kubernetes is the de-facto standard for container orchestration and management. It provides a comprehensive platform for deploying, scaling, and managing containerized applications.

Here are some reasons why you need Kubernetes:

  • Scalability and High Availability – Kubernetes make it easy to scale up or down your application as needed. It enables high availability by automatically restarting containers that fail, rescheduling containers on other nodes if a node goes down, and replicating containers to ensure that your application is always available.
  • Declarative – Configuration Kubernetes uses a declarative approach to configuration. You describe the desired state of your application, and Kubernetes takes care of the rest. This means you don’t have to worry about the underlying infrastructure and can focus on your application’s logic.
  • Automation – Kubernetes automates many tasks, such as rolling out updates, scaling, and self-healing. It eliminates manual intervention, reducing the likelihood of human error and freeing up your team’s time.
  • Portability – Kubernetes is a portable platform that runs on any cloud, on-premises, or hybrid environment. It allows you to move your applications seamlessly between different environments without changing the underlying infrastructure.
  • Ecosystem – Kubernetes has a large and rapidly growing ecosystem with many tools and services available.
  • Resilience – Kubernetes provides built-in mechanisms for ensuring that applications are always available, even if a container or node fails. It can automatically restart containers, migrate them to healthy nodes, and ensure that applications run reliably.
  • Flexibility – Kubernetes provides a flexible platform for deploying and managing applications. It supports a wide range of container runtimes, including Docker and containers, and allows you to use storage, networking, and monitoring tools.

What are Containers?

Before we dive deeper into Kubernetes, let’s first understand what containers are. Containers are lightweight and portable executable units that package application code and all its dependencies in a single bundle. They provide a consistent runtime environment, regardless of the underlying infrastructure, making moving applications between different environments easier.

How Kubernetes Works?

Kubernetes abstracts the underlying infrastructure and provides a platform for running containerized workloads. It allows you to define the desired state of your application using declarative configuration files, which Kubernetes will then automatically manage and maintain.

Some of the core components of Kubernetes include:

  • Nodes – These are the physical or virtual machines that run your containers.
  • Pods – A pod is the smallest unit of deployment in Kubernetes. It’s a logical host for one or more containers.
  • Services – Services are an abstraction that exposes a set of pods to the network.
  • Controllers – Controllers are responsible for maintaining the desired state of your application. They ensure that the right number of pods are running and that they are healthy and up-to-date.

Kubernetes works by providing a framework for managing containerized applications. It uses a set of APIs to communicate with the underlying infrastructure, such as container runtime, storage, and networking. Kubernetes consists of various components, such as the API server, etcd, controller manager, and scheduler.

API Server

The API server is the central control plane of Kubernetes. It exposes the Kubernetes API, which allows clients to communicate with the Kubernetes cluster. The API server is responsible for authenticating and authorizing client requests, validating and processing API objects, and updating the state of the cluster.


etcd is a distributed key-value store used by Kubernetes to store the configuration data of the cluster. It provides a consistent and reliable way to store and retrieve configuration data across the cluster. etcd is a critical component of Kubernetes, and its availability is essential for the proper functioning of the cluster.

Controller Manager

The controller manager is responsible for maintaining the desired state of the cluster. It watches the state of the cluster through the API server and compares it to the desired state specified in the Kubernetes objects. If there is a difference between the current and desired state, the controller manager takes appropriate actions to bring the cluster back to the desired state.


The scheduler is responsible for scheduling workloads on the cluster’s worker nodes. It watches for new workloads that need to be scheduled and selects an appropriate node to run the workload based on the resource requirements and availability of the node.

Worker Nodes

Worker nodes are the machines that run containerized workloads. Each worker node runs a container runtime, such as Docker or CRI-O, to manage the containers. In addition, the worker nodes communicate with the API server to receive instructions on what containers to run and how to manage them.

The components of a Kubernetes cluster. Source: https://kubernetes.io/
The components of a Kubernetes cluster. Source: https://kubernetes.io/


In conclusion, while Kubernetes offers numerous benefits for managing containerized applications, security should always be a top concern for businesses. With the increasing frequency and severity of cyberattacks, a security solution like Singularity Cloud can help businesses stay protected against modern threats.

Singularity Cloud offers advanced endpoint protection and real-time threat prevention, leveraging artificial intelligence and machine learning to detect and respond to threats in real time. This helps businesses prevent data breaches and avoid costly downtime and ensures compliance with various regulations and standards.

By incorporating SentinelOne Cloud into their Kubernetes environments, businesses can add an extra layer of security to their containerized applications and protect themselves from cyber threats. As a result, customers can rest assured that their applications and data are safe and secure, allowing them to focus on achieving their business objectives without worrying about cybersecurity issues.

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