Remove Empty Namespaces Operator

A Kubernetes operator that deletes namespaces without resources.

Description

Operator iterates over all namespaced api-resources in every namespace. If there are no resources, it annotates namespace as a candidate for deletion. The namespace will be deleted after specified time interval if there will be no resources still.

So operator doesn't delete namespace instantly: first time it marks namespace and after interval operator deletes ns if it's still empty.

Installation

kubectl apply -k .

Configuration

See settings.yaml as example

interval: "18000"  # 5h
initialDelay: "300"  # 5m
ignoredResouces:
  - apiGroup: ""
    kind: ConfigMap
    nameRegExp: kube-root-ca.crt
  - apiGroup: ""
    kind: ConfigMap
    nameRegExp: werf-synchronization
  - apiGroup: ""
    kind: Secret
    nameRegExp: default-token-\w+$
  - apiGroup: ""
    kind: ServiceAccount
    nameRegExp: default
protectedNamespaces:
  - protected-one
  - default
  - kube-public
  - kube-system

• interval - interval between namespaces check
• initialDelay - 'grace period' before new namespace will be checked
• ignoredResouces - namespace will be treated as empty if it contains only 'ignored resources'
• protectedNamespaces - these namespaces will not be deleated dispite of emptiness

Note that usually there is no need to add kubernetes default namespaces (default, kube-public and kube-system) to protectedNamespaces because they have some resources inside in the most cases. But you certainly can do it just to be sure that nothing will happen with them. Also, if your kube-system is empty you are probably it trouble already :)