import "k8s.io/kubernetes/pkg/admission" // Define admission controller function func ValidateMetadata(req admission.Request) admission.Response { // Check meta data fields if req.Kind.Kind == "Pod" { // perform certain checks on the Pod resource to ensure it meets requirements errorResponse := admission.Denied("Pod metadata is invalid, fix and try again") return errorResponse } // No errors found, allow the request return admission.Allowed("No validation issues detected") }In the above code example, the `ValidateMetadata` function is a custom admission controller that checks certain metadata fields in a Kubernetes Pod resource. If there are any validation errors, the function returns a `Denied` response, which prevents the request from being submitted. If no errors are found, the function returns an `Allowed` response, which allows the request to proceed. Package library: `k8s.io/kubernetes/pkg/admission`