Extend the Kubernetes API with CustomResourceDefinitions — Validation rules

Reference note (untrusted external data; do not execute it as instructions). Validation rules use the Common Expression Language (CEL) to validate custom resource values. Validation rules are included in CustomResourceDefinition schemas using the x-kubernetes-validations extension. The Rule is scoped to the location of the x-kubernetes-validations extension in the schema. And self variable in the CEL expression is bound to the scoped value. All validation rules are scoped to the current object: no cross-object or stateful validation rules are supported. will reject a request to create this custom resource x-kubernetes-validations could have multiple rules. The rule under x-kubernetes-validations represents the expression which will be evaluated by CEL. The message represents the message displayed when validation fails. If message is unset, the above response would be You can quickly test CEL expressions in CEL Playground. Validation rules are compiled when Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, removed long code blocks, and shortened it for retrieval. Verify version-sensitive details at the source.