kraan

kraan - Building platforms on top of K8s

This project is currently in the early stages of development and expected to release beta versions by end of September.

What is kraan?

kraan helps you deploy and manage 'layers' on top of kubernetes. By applying layers on top of K8s clusters, you can build focused platforms on top of K8s e.g ML platforms, Data platform etc. Each layer is a collection of addons and can have dependencies established between the layers. i.e a "mgmt-layer" can depend on a "common-layer". Kraan will always ensure that the addons in the "common-layer" are deployed successfully before deploying the "mgmt-layer" addons. A layer is represented as a kubernetes custom resource and kraan is an operator that is deployed into the cluster and works constantly to reconcile the state of the layer custom resource.

kraan is powered by flux2 and builds on top of projects like source-controller and helm-controller.

Use cases

Kraan can be used wherever you have requirements to manage add-ons on top of k8s clusters and especially when you want to package the addons into dependant categories. If you have a mutating webhook injecting a side-car and set of security plugins which should always be deployed first before other addons,then layers concept in Kraan will help there. However, Kraan is even more powerful when it comes to building custom platforms on top of k8s like the one shown below.

kraan promotes the idea of building model based platforms on top of k8s i.e you can build a "general purpose" k8s platform which might have a "common" and "security" layers which packages all the common tooling, applications inside that cluster might need as well as organization specific bits (e.g org specific security addons etc). You can also say that the "common-layer" depends-on "security-layer" to be deployed first. This "general purpose" k8s platform can then be extended by applying another "ml-layer" which can then be exposed as an ML platform to the development teams. The end result here is developers working on top of secure and custom-built platforms which adheres to organization specific policies etc. And rolling out updates to this ML platform is as simple as "kubectl apply -f <LAYERS_DIR>" where new versions of the layers are deployed into the cluster and kraan operator will constantly work towards getting that platform to match the latest desired state!

The below diagram shows how you can use kraan to build a focused multi-cloud platform where "common" and "security" layers are shared across clouds whereas other layers become cloud specific.

Design

Kraan is a kubernetes controller that is built on top of k8s custom resources. It works in tandem with source-controller and helm-controller and hence they are always deployed together. The detailed design documentation can be found here

Usage

See User Guide for usage instructions.

See Developer Guide for development.

Contributions

Contributions are very welcome. Please read the contributing guide or see the docs.