What is cdk8s?

cdk8s is a software development framework for defining Kubernetes applications and reusable abstractions using familiar programming languages and rich object-oriented APIs. cdk8s generates pure Kubernetes YAML - you can use cdk8s to define applications for any Kubernetes cluster running anywhere.

Info

The documentation here relates to version 2.x of the cdk8s toolchain, which is the latest. If you are still using version 1.x, please refer to the Migrating from 1.x Guide.

Read our blog or watch our CNCF webinar to learn more and see a live demo of cdk8s in action.

How does it work?

cdk8s apps are programs written in one of the supported programming languages. They are structured as a tree of constructs.

The root of the tree is an App construct. Within an app, users define any number of charts (classes that extend the Chart class). Each chart is synthesized into a separate Kubernetes manifest file. Charts are, in turn, composed of any number of constructs, and eventually from resources, which represent any Kubernetes resource, such as Pod, Service, Deployment, ReplicaSet, etc.

cdk8s apps only define Kubernetes applications, they don’t actually apply them to the cluster. When an app is executed, it synthesizes all the charts defined within the app into the dist directory, and then those charts can be applied to any Kubernetes cluster using kubectl apply -f dist/chart.k8s.yaml or a GitOps tool like Flux.

cdk8s is based on the design concepts and technologies behind the AWS Cloud Development Kit, and can interoperate with AWS CDK constructs to define cloud-native applications that include both Kubernetes resources and other CDK constructs as first class citizens.