This sample repository show demo use of Finalizer and Initializer. Finalizer are used here for garbage collection.

Repostory: k8s-initializer-finalizer-practice

Here, I have created a custom controller for pods, just like Deployment.

1. I have used Initializer to add busybox sidecar or finalizer to underlying pods. See here.
2. When a CustomDeployment crd is deleted, kubernetes set DeletionTimestamp but does not delete it if it has finalizer. Then controller checks if it has finalizer. If it has finalizer, it deletes its pod and remove the finalizer. Then the crd terminate. See here.