Expose Default and Validate functions on NovaSpecCore

The higher level meta operator will include the NovaSpecCore now in the
OpenStackControlPlane CRD and therefore it needs to default and validate
that struct in its webhooks, so the necessary functions are exposed.
This patch manages to avoid duplicating the validation logic because the
the NovaSpecCore is now directly embedded in the NovaSpec and therefore
validations written for NovaSpecCore can be also called on NovaSpec
too.

Jira: OSPRH-4835

api/v1beta1/nova_webhook.go

@@ -74,10 +74,15 @@ func (r *Nova) Default() {
 	r.Spec.Default()
 }
 
-// Default - set defaults for this Nova spec
+// Default - set defaults for this NovaCore spec.
 func (spec *NovaSpec) Default() {
 	spec.NovaImages.Default(novaDefaults)
+	spec.NovaSpecCore.Default()
+}
 
+// Default - set defaults for this Nova spec. Expected to be called from
+// the higher level meta operator.
+func (spec *NovaSpecCore) Default() {
 	// NOTE(gibi): this cannot be expressed as kubebuilder defaults as the
 	// MetadataServiceTemplate is used both in the cellTemplate and in the
 	// NovaSpec but we need different defaults in the two places
@@ -113,7 +118,7 @@ func (spec *NovaSpec) Default() {
 
 var _ webhook.Validator = &Nova{}
 
-func (r *NovaSpec) ValidateCellTemplates(basePath *field.Path) field.ErrorList {
+func (r *NovaSpecCore) ValidateCellTemplates(basePath *field.Path) field.ErrorList {
 	var errors field.ErrorList
 
 	if _, ok := r.CellTemplates[Cell0Name]; !ok {
@@ -203,17 +208,22 @@ func (r *NovaSpec) ValidateCellTemplates(basePath *field.Path) field.ErrorList {
 	return errors
 }
 
-func (r *NovaSpec) ValidateAPIServiceTemplate(basePath *field.Path) field.ErrorList {
+func (r *NovaSpecCore) ValidateAPIServiceTemplate(basePath *field.Path) field.ErrorList {
 	errors := ValidateAPIDefaultConfigOverwrite(
 		basePath.Child("apiServiceTemplate").Child("defaultConfigOverwrite"),
 		r.APIServiceTemplate.DefaultConfigOverwrite)
 	return errors
 }
 
-// ValidateCreate validates the NovaSpec during the webhook invocation. It is
+// ValidateCreate validates the NovaSpec during the webhook invocation.
+func (r *NovaSpec) ValidateCreate(basePath *field.Path) field.ErrorList {
+	return r.NovaSpecCore.ValidateCreate(basePath)
+}
+
+// ValidateCreate validates the NovaSpecCore during the webhook invocation. It is
 // expected to be called by the validation webhook in the higher level meta
 // operator
-func (r *NovaSpec) ValidateCreate(basePath *field.Path) field.ErrorList {
+func (r *NovaSpecCore) ValidateCreate(basePath *field.Path) field.ErrorList {
 	errors := r.ValidateCellTemplates(basePath)
 	errors = append(errors, r.ValidateAPIServiceTemplate(basePath)...)
 	errors = append(
@@ -238,10 +248,15 @@ func (r *Nova) ValidateCreate() (admission.Warnings, error) {
 	return nil, nil
 }
 
-// ValidateUpdate validates the NovaSpec during the webhook invocation. It is
+// ValidateUpdate validates the NovaSpec during the webhook invocation.
+func (r *NovaSpec) ValidateUpdate(old NovaSpec, basePath *field.Path) field.ErrorList {
+	return r.NovaSpecCore.ValidateUpdate(old.NovaSpecCore, basePath)
+}
+
+// ValidateUpdate validates the NovaSpecCore during the webhook invocation. It is
 // expected to be called by the validation webhook in the higher level meta
 // operator
-func (r *NovaSpec) ValidateUpdate(old NovaSpec, basePath *field.Path) field.ErrorList {
+func (r *NovaSpecCore) ValidateUpdate(old NovaSpecCore, basePath *field.Path) field.ErrorList {
 	errors := r.ValidateCellTemplates(basePath)
 	errors = append(errors, r.ValidateAPIServiceTemplate(basePath)...)
 	errors = append(