Deletion Protection

FEATURE STATE: Kruise v0.9.0

This feature provides a safety policy which could help users protect Kubernetes resources and applications' availability from the cascading deletion mechanism.

Usage

Firstly, users have to enable the ResourcesDeletionProtection feature-gate during Kruise installation or upgrade.

Then, users can add the label named policy.kruise.io/delete-protection to some specific resources. The values can be:

• Always: this object will always be forbidden to be deleted, unless the label is removed
• Cascading: this object will be forbidden to be deleted, if it has active resources owned

The resources supported and the cascading judgement relationship:

Kind	Group	Version	Cascading judgement
Namespace	core	v1	whether there is active Pods in this namespace
CustomResourceDefinition	apiextensions.k8s.io	v1beta1, v1	whether there is existing CRs of this CRD
Deployment	apps	v1	whether the replicas is 0
StatefulSet	apps	v1	whether the replicas is 0
ReplicaSet	apps	v1	whether the replicas is 0
CloneSet	apps.kruise.io	v1alpha1	whether the replicas is 0
StatefulSet	apps.kruise.io	v1alpha1, v1beta1	whether the replicas is 0
UnitedDeployment	apps.kruise.io	v1alpha1	whether the replicas is 0

Deletion Protection of service and ingress

FEATURE STATE: Kruise v1.6.0

Kruise support the deletion protection of service and ingress resources, the strategy only supports Always, for example:

apiVersion: v1
kind: Service
metadata:
  labels:
    policy.kruise.io/delete-protection: Always
  name: test-web

Risk

Using objectSelector in webhook configuration, Kruise webhook will only handle those Namespace/CustomResourceDefinition/Deployment/StatefulSet/ReplicaSet resources with policy.kruise.io/delete-protection label.

So, if all kruise-manager Pods are crashed or in other abnormal states, kube-apiserver fails to call the deletion webhook, only the resources with policy.kruise.io/delete-protection label can not be deleted temporarily.