jsPolicy
Easier & faster Kubernetes policies using JavaScript or TypeScript
...and Kubernetes uses JSON by converting your YAML to JSON during every API request. Run custom JavaScript controllers that react to any changes to the objects in your cluster (controller policies are reactive, so they are not webhooks and part of a Kubernetes API server request but instead react to Events in your cluster after they have happened). With controller policies you can write resource sync mechanisms, enforce objects in namespaces, garbage collectors or fully functional CRD controllers. Create a functional webhook with a single line of JavaScript or write your own fully blown custom StatefulSet controller in TypeScript with jsPolicy.