k8s CustomResourceDefinition invalid 错误

安装 CRD 出现这个错误，多数是版本问题，缺少openAPIV3Schema段定义。

The CustomResourceDefinition "crontabs.stable.example.com" is invalid:
* spec.versions[0].schema.openAPIV3Schema: Required value: schemas are required
* spec.versions[1].schema.openAPIV3Schema: Required value: schemas are required

参考如下模板：

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: eventbus.argoproj.io
spec:
  group: argoproj.io
  names:
    kind: EventBus
    listKind: EventBusList
    plural: eventbus
    shortNames:
    - eb
    singular: eventbus
  scope: Namespaced
  versions:
  - name: v1alpha1
    schema:
      openAPIV3Schema:
        properties:
          apiVersion:
            type: string
          kind:
            type: string
          metadata:
            type: object
          spec:
            type: object
            x-kubernetes-preserve-unknown-fields: true
          status:
            type: object
            x-kubernetes-preserve-unknown-fields: true
        required:
        - metadata
        - spec
        type: object
    served: true
    storage: true
    subresources:
      status: {}