Here are the links explaining how to create CRD validations: https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#validation https://stupefied-goodall-e282f7.netlify.com/contributors/design-proposals/api-machinery/customresources-validation/#external-customresourceschema-type
Here are the links explaining how to create CRD validations:
https://kubernetes.io/docs/tasks/access-kubernetes-api/custom-resources/custom-resource-definitions/#validation
https://stupefied-goodall-e282f7.netlify.com/contributors/design-proposals/api-machinery/customresources-validation/#external-customresourceschema-type