Kubernetes is a widely used open-source solution for managing virtual containers. Officially launched in 2014, it makes it possible to manage several containers at the same time and automate daily operation tasks that would require great effort.
Kubernetes can improve application reliability and reduce the amount of time and resources devoted to cloud applications, enabling organizations to achieve greater operational efficiency.
In this article, we will learn how this technology works and why it is so important in the development of Cloud Computing.
Containers and the evolution of applications
Before we delve into the details of what Kubernetes is and how it works, let’s understand how the need for a container management tool arose.
Containers are lightweight and portable units of execution that package an application’s code with its dependencies and configurations, enabling it to run consistently in any environment, whether it’s in development, testing, or production.
Initially, organizations ran applications directly on physical servers. In this model, there was limited control over server resources, leading to inefficient application execution and higher costs for infrastructure maintenance.
With the advent of virtual machines, there was a shift in this paradigm. In addition to providing broader control over server computational resources, virtualization brought scalability and enabled the evolution and popularization of cloud computing.
Virtual machines still have full capabilities, and often it’s not necessary to virtualize all functions. In this context, containers emerge as an alternative for a lighter form of virtualization that allows for the optimization of computational resources. Functioning as isolated resource processes, they bring the same properties as conventional virtualization but isolate only the properties necessary for the operationalized application.
However, just like conventional virtualization, managing multiple execution workloads across various containers proved to be a challenge. It’s in this context that a group of engineers at Google developed Kubernetes, the result of several years of learning in the operationalization of these processes.
What is Kubernetes?
Kubernetes (also abbreviated as K8s) is an open-source platform developed to automate the deployment, scaling, and management of containerized applications. In this way, it acts as an orchestrator, handling all aspects of an application’s lifecycle.
Due to its comprehensive capabilities, Kubernetes has become a standard tool for deploying and managing container-based applications in the cloud, making cloud computing more efficient and reliable.
Why is Kubernetes so important?
The reasons why Kubernetes has become so important for companies that are joining the cloud or optimizing their structure are many, but we can highlight a few:
- Advanced container orchestration: Kubernetes provides a robust and scalable solution for orchestrating containers. It automates the deployment, scaling, and management of applications, making it easier for companies to manage their workloads in complex cloud environments.
- Portability and flexibility: It allows applications to be packaged, making them independent of the underlying infrastructure. This provides portability as applications can run consistently in any environment, whether in public, private, or hybrid clouds.
- Scalability: It offers automatic scaling, enabling applications to dynamically adapt to demand. As workload increases, Kubernetes can automatically add new container instances to handle the increased demand. And when the load decreases, it can reduce the number of instances, saving resources.
- Automation and operational efficiency: With Kubernetes, deployment, updates, and monitoring of applications are automated, reducing the need for manual intervention. This enhances operational efficiency, allowing development teams to focus on other tasks.
- Simplified microservices management: It is highly suitable for microservices architectures, where applications consist of multiple independent and interconnected services. It facilitates management and communication.
- Greater reliability and resilience: It offers self-healing mechanisms, monitoring, and load balancing that improve the reliability of applications. If a container fails, Kubernetes restarts it automatically. Moreover, it distributes traffic among running containers to ensure continuous service availability.
- Active community and extensive ecosystem: Kubernetes is an open-source project with a highly active community of developers and users. This means there is broad support, frequent updates, and a variety of tools and plugins available to extend its functionalities.
In summary, companies have embraced Kubernetes because it offers a complete and reliable solution for dealing with the complexity of cloud environments, making it easier to deploy, manage and scale containerized applications, as well as providing greater flexibility and operational efficiency.
Understanding the Kubernetes architecture
The architecture of Kubernetes is designed to be flexible, scalable, and highly available.
As we mentioned earlier, Kubernetes is a container manager, a type of unconventional virtualization system that, unlike conventional virtualization, doesn’t virtualize the entire environment, but only what’s necessary for the application to function. As a result, they are lighter and use fewer resources.
Kubernetes manages a collection of containers, which is referred to as a cluster. These containers are categorized into three types:
- Node: where the execution of the encapsulated application takes place. Your set is usually called a worker;
- etc: is the distributed database and stores everything that happens in the cluster, including its state;
- Master: is the type that manages and maintains the state of the cluster. The main components of the tool are executed there, such as the Scheduler, the Controller Manager, and the API.
More information about how the cluster works
There are other important features to understand to understand more about the tool. Check it out:
- Control Plane: known as the brain of the cluster, it is a set of master machines, which manages the main components of the system;
- Pod: These are the basic units of a Kubernetes cluster. Encapsulate one or more containers. When deploying an application, you create one or more Pods;
- Deployment: is the type of object that encompasses the functionalities that automate the typical steps of software development, such as manual and semi-automated deployment;
These are some of the main concepts of the Kubernetes architecture. As we mentioned earlier, it is very extensive and detailed, so if you want to know more about these details, we recommend reading the tool’s official documentation.
Kubernetes vs Docker: understand the differences
Kubernetes and Docker are different but complementary technologies that are often mentioned together because they are used together to manage and deploy containerized applications.
Docker is a platform that allows you to build applications in containers. It provides a way to create, manage and run isolated containers that encapsulate an application with its dependencies and libraries, ensuring that it works consistently in any environment.
Kubernetes, as we have seen, is a solution that provides a comprehensive set of tools to manage groups of containers (called clusters), ensuring that applications run reliably and scalably.
The tool abstracts the underlying infrastructure details and offers an API to configure the deployment, scaling, updating, and monitoring configuration of containerized applications, offering powerful features such as load balancing, auto-scaling, self-healing, configuration management, and storage.
Understand the main differences between these two tools:
Scope: Docker is focused on creating, distributing, and running containers. Kubernetes is focused on orchestrating and managing containers in a cluster environment.
Functionality: Docker is the technology that allows the creation and execution of isolated containers. Kubernetes is an orchestration platform that automates the management of multiple containers, ensuring they are run correctly, scaled as needed, and maintained in high availability.
Scalability: Docker doesn’t provide native features for automatic scaling or container self-healing. On the other hand, Kubernetes offers these capabilities, enabling applications to dynamically adjust to workload changes.
Purpose: Docker is used to create and run containers, whether in development, testing, or production environments. Kubernetes is used to manage and orchestrate containers at scale, making it easier to deploy and manage applications in complex environments.