This is a reimplementation of StatefulSet (now including rolling updates) as a CompositeController.
CatSet also demonstrates using a finalizer with a lambda hook to support graceful, ordered teardown when the parent object is deleted. Unlike StatefulSet, which previously exhibited this behavior only because of a client-side kubectl feature, CatSet ordered teardown happens on the server side, so it works when the CatSet is deleted through any means (not just kubectl).
For this example, you need a cluster with a default storage class and a dynamic provisioner.
- Install Metacontroller
Deploy the controller
kubectl create configmap catset-controller -n metacontroller --from-file=sync.js kubectl apply -f catset-controller.yaml
Create a CatSet
kubectl apply -f my-catset.yaml