apiVersion: v1
kind: Pod
metadata:
...
ownerReferences:
- apiVersion: apps/v1
controller: true
blockOwnerDeletion: true
kind: ReplicaSet
name: my-repset
uid: d9607e19-f88f-11e6-a518-42010a800195
...
The role of the Kubernetes garbage collector is to delete certain objects that once had an owner, but no longer have an owner.
Deleting dependents automatically is called cascading deletion
有两种级联删除
background and foreground
There are two modes of cascading deletion: background and foreground.
orphaned
If you delete an object without deleting its dependents automatically, the dependents are said to be orphaned.
Foreground cascading deletion
在前台级联删除中，根对象首先进入“正在删除”状态
- 通过REST API，对象仍然可见
- 对象的deletionTimestamp被设置
- 对象的元数据。终结器包含值“foregroundDeletion”
一旦设置了“正在删除”状态，垃圾收集器就会删除对象的依赖项。一旦垃圾收集器删除了所有的“阻塞”依赖项(ownerreference.blockownerdelete =true的对象)，它就会删除owner对象
Background cascading deletion
Kubernetes立即删除owner对象，垃圾收集器然后删除后台的依赖项
To delete dependents automatically using kubectl, set --cascade to true
To orphan dependents, set --cascade to false.
The default value for --cascade is true.
Here's an example that orphans the dependents of a ReplicaSet:
kubectl delete replicaset my-repset --cascade=false
