CRD - Custom Resource Definitions on building Kubernetes Cloud-Native applications

Yobitel
3 min readFeb 2, 2022

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Adopt cloud-native Kubernetes applications built with custom CRD operators to orchestrate resources across your Kubernetes cluster, including horizontal pod auto-scaling, when you want, and Use cloud-native Kubernetes applications to quickly get a working, production-ready Kubernetes cluster on-premises or in the cloud.

While it’s true that, today, Kubernetes is the de-facto platform for distributed applications, Kubernetes is not an end in and of itself. Kubernetes is a collection of abstractions that enable you to build and manage your own distributed applications.

In this post, we’ll introduce you to cloud-native Kubernetes applications, and we’ll show you how to build and deploy your own cloud-native Kubernetes applications on Elastic Kubernetes Service (EKS).

Getting started with Kubernetes & CRD Operators

Kubernetes is a cluster management system that can run on-premises or in the cloud. It was designed to be an open-source, extensible platform for building and deploying containerized applications.

At a high level, Kubernetes runs in a cluster of machines (nodes) that are each capable of running a single application. A Kubernetes cluster is made up of a Kubernetes master, which runs on a single node, and a set of Kubernetes worker nodes. The Kubernetes master coordinates the running of pods, or containers, on the worker nodes.

For a Kubernetes cluster to work, you need to deploy the Kubernetes master and worker nodes on separate machines. You also need to make sure that the Kubernetes master and worker nodes have network connectivity to one another.

To make sure that Kubernetes runs properly, you need to configure the master nodes, worker nodes, and Kubernetes configuration files, which tell Kubernetes how to run your application.

Deploying Kubernetes on AWS Elastic Kubernetes Service (EKS) is a one-click process. You can follow these steps to set up a Kubernetes cluster on your AWS account:

To deploy a Kubernetes cluster on your own AWS account, you need to enable the Amazon EKS service on your AWS account. After you enable the services on your AWS account, you can create an EKS cluster. You can choose to use an existing Kubernetes cluster, or you can deploy your own Kubernetes cluster.

Now, you need to configure your Kubernetes configuration files with Helm Charts including service deployment files, such as the Kubernetes manifest file and the Kubernetes configuration file, that tell Kubernetes how to deploy your application. You can also specify the number of Kubernetes worker nodes that you want to run in your Kubernetes cluster with service account secret, master node count, node size, node type, node labels, node volume size, node volume type, and node volume labels.

Here, the deployment file prepared as a Helm chart needs to be converted as a CRD operator file The deployment file and the operator file are passed to the operator tool to generate a Kubernetes manifest file. The manifest file contains the container images for your Kubernetes worker nodes, and it is the container images that are run on the Kubernetes worker nodes.

Through CRD operator, we achieve building an extra layer of attributes such as Horizontal Pod auto-scaling (HPA), RBAC, Service accounts, security context, storage PVC mirroring, sidecar additions, and totally bring it up together and compile as a shield for one-click installable Kubernetes image.

Cloud-native Kubernetes applications are applications that are designed to run on cloud-native platforms such as marketplaces in EKS, AKS, and Google Cloud Platform. The goal of cloud-native Kubernetes applications is to remove the need to have to build and deploy applications using the standard tooling for containerized applications on step by step ongoing deployment mode. Cloud-native Kubernetes applications are optimized for scalability, availability, and performance.

To build a cloud-native Kubernetes application, you can use the kubebuilder tool, which is included in the Kubernetes Operator GitHub repository. When you run the kubebuilder tool, it will automatically build the Kubernetes manifest file, the Kubernetes configuration file, and the deployment file that you need to deploy your application.

Summary:

Cloud-native Kubernetes applications are applications that are built for cloud-native platforms, such as marketplaces in EKS, AKS, and Google Cloud Platform. The goal of cloud-native Kubernetes applications is to remove the need to have to build and deploy applications using the standard tooling for containerized applications. For enterprises that are looking for professional support in Kubernetes and cloud-native Kubernetes application, Please do connect with experts from Yobitel.

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Yobitel

Yobitel a Cloud-Native SaaS Multi-Cluster Containerized Serverless Application Services Provider.