Kubernetes - The Ultimate Platform for Containerized Application Management
Kubernetes offers a platform to deploy container-based Docker applications. Let us go through what Kubernetes is, how it works and what are its benefits.
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We know Docker transformed the software industry by introducing containerization. Docker made it easy for applications to package code, runtime, libraries, configurations, etc all in one place. Cut to Kubernetes, which offers a platform to deploy these container-based Docker applications.
Today in this blog, let us go through what Kubernetes is, how it works and what are its benefits.
-Kubernetes, also known as K8S, is an orchestration platform that facilitates the management of containerized applications by the means of networking, storage and configuration, and deployment.
-An open-source project by Google launched in 2014, Kubernetes can be called a container-management tool that utilizes an API for managing various services like scaling, deployment, and execution of applications.
-Kubernetes not only simplifies the application deployment and management but also offers a myriad of other features like load balancing, automated rollbacks, storage services and also taking care of the health of the entire application.
The objects and controllers form the building blocks of the application. There are various abstractions in the API which we need to understand in order to know about the working of Kubernetes architecture.
Let us in brief, go over these objects and controllers:
1) Pod - A pod is a group of one or more containers. The pods are governed by a K8S configuration that guides the behavior of the containers. Here is a detailed blog about Kubernetes pods.
2) Service - This is an abstraction that describes the available pods and also defines the ways of accessing them.
3) Volume - Since containers are ephemeral in nature, the volume abstraction in Kubernetes allows data persistency.
4) Namespace - Namespace allows you to create multiple virtual K8S clusters, each cluster serving a particular purpose or a specific project.
5) ReplicaSet (RS) - A K8S replica set is a service that makes sure necessary pods are running. This service is responsible for recreating new pods in the event of any pod crash.
6) Deployment - Deployments are used to define high availability policies to containers.
7) StatefulSet - This is an API object to manage stateful applications like databases.
8) DaemonSet - Ensures that some worker nodes run a copy of a pod
9) Job - The responsibility of the job is to create one or more pods, run a certain task to completion, etc.
Below is a detailed architectural diagram of K8S.
-Due to its simple and easy approach to managing container-based applications, Kubernetes has become the first choice when it comes to running these applications in the cloud, with prime cloud providers like AWS and Azure offering Kubernetes services. Have a look at some of the benefits of Kubernetes.
Flexibility to Run Immutable Infrastructure
Kubernetes Engine supports the concept of immutable infrastructure where servers are never modified. If any changes are required to be made on the server, a new server is built with the modifications and is replaced in place of the old server.
K8S is the ultimate platform for providing horizontal scaling and the application can be scaled whenever needed using a command-line interface.
In case of any mishap or failure, Kubernetes automatically rolls back the change and ensures the health of the application is always intact.
One of the most important benefits of K8S is to balance the load thanks to containerization.
Due to its compatibility with major cloud service providers, Kubernetes automatically mounts local or public cloud or network storage.
K8S successfully manages the configuration settings without having to rebuild the image.
Not only does Kubernetes rollback changes, but it is also capable of restarting failed containers, replacing and rescheduling containers, killing containers that don’t respond to pre-defined health parameters, etc
K8S also schedules and executes the batch of containers set using specific conditions and requirements.
Published at DZone with permission of Sajan Agrawal. See the original article here.
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