markers: add support for optionalOldSelf in XValidation marker

Signed-off-by: Bryce Palmer <bpalmer@redhat.com>

Author: everettraven

pkg/crd/markers/validation.go

@@ -335,6 +335,7 @@ type XValidation struct {
 	MessageExpression string `marker:"messageExpression,optional"`
 	Reason            string `marker:"reason,optional"`
 	FieldPath         string `marker:"fieldPath,optional"`
+	OptionalOldSelf   *bool   `marker:"optionalOldSelf,optional"`
 }
 
 func (m Maximum) ApplyToSchema(schema *apiext.JSONSchemaProps) error {
@@ -603,6 +604,7 @@ func (m XValidation) ApplyToSchema(schema *apiext.JSONSchemaProps) error {
 		MessageExpression: m.MessageExpression,
 		Reason:            reason,
 		FieldPath:         m.FieldPath,
+		OptionalOldSelf:   m.OptionalOldSelf,
 	})
 	return nil
 }

pkg/crd/markers/zz_generated.markerhelp.go

@@ -43,7 +43,7 @@ import (
 const DefaultRefValue = "defaultRefValue"
 
 // CronJobSpec defines the desired state of CronJob
-// +kubebuilder:validation:XValidation:rule="has(oldSelf.forbiddenInt) || !has(self.forbiddenInt)",message="forbiddenInt is not allowed",fieldPath=".forbiddenInt",reason="FieldValueForbidden"
+// +kubebuilder:validation:XValidation:rule="has(oldSelf.forbiddenInt) || !has(self.forbiddenInt)",message="forbiddenInt is not allowed",fieldPath=".forbiddenInt",reason="FieldValueForbidden",optionalOldSelf=true
 type CronJobSpec struct {
 	// The schedule in Cron format, see https://en.wikipedia.org/wiki/Cron.
 	Schedule string `json:"schedule"`

pkg/crd/testdata/cronjob_types.go

@@ -9156,6 +9156,7 @@ spec:
             x-kubernetes-validations:
             - fieldPath: .forbiddenInt
               message: forbiddenInt is not allowed
+              optionalOldSelf: true
               reason: FieldValueForbidden
               rule: has(oldSelf.forbiddenInt) || !has(self.forbiddenInt)
           status: