Add notificationBusInstance webhook validation

Because we can't control user input, this patch introduces a webhook
function to validate what we expect users to set as notificationsBusInstance
top-level parameter.

Signed-off-by: Francesco Pantano <[email protected]>

Author: fmount

apis/core/v1beta1/openstackcontrolplane_webhook.go

@@ -132,6 +132,10 @@ func (r *OpenStackControlPlane) ValidateCreate() (admission.Warnings, error) {
 		allErrs = append(allErrs, err)
 	}
 
+	if err := r.ValidateNotificationsBusInstance(basePath); err != nil {
+		allErrs = append(allErrs, err)
+	}
+
 	if len(allErrs) != 0 {
 		return allWarn, apierrors.NewInvalid(
 			schema.GroupKind{Group: "core.openstack.org", Kind: "OpenStackControlPlane"},
@@ -161,6 +165,10 @@ func (r *OpenStackControlPlane) ValidateUpdate(old runtime.Object) (admission.Wa
 		allErrs = append(allErrs, err)
 	}
 
+	if err := r.ValidateNotificationsBusInstance(basePath); err != nil {
+		allErrs = append(allErrs, err)
+	}
+
 	if len(allErrs) != 0 {
 		return nil, apierrors.NewInvalid(
 			schema.GroupKind{Group: "core.openstack.org", Kind: "OpenStackControlPlane"},
@@ -1122,3 +1130,23 @@ func (r *OpenStackControlPlane) ValidateTopology(basePath *field.Path) *field.Er
 	}
 	return nil
 }
+
+func (r *OpenStackControlPlane) ValidateNotificationsBusInstance(basePath *field.Path) *field.Error {
+	notificationsField := basePath.Child("notificationsBusInstance")
+	// no notificationsBusInstance field set, nothing to validate here
+	if r.Spec.NotificationsBusInstance == nil {
+		return nil
+	}
+	// When NotificationsBusInstance is set, fail if it does not represent a valid string
+	if len(*r.Spec.NotificationsBusInstance) == 0 {
+		return field.Invalid(notificationsField, "notificationsBusInstance", "notificationsBusInstance is not a valid string")
+	}
+	// NotificationsBusInstance is set and must be equal to an existing
+	// deployed rabbitmq instance, otherwise we should fail
+	for k := range(*r.Spec.Rabbitmq.Templates) {
+		if *r.Spec.NotificationsBusInstance == k {
+			return nil
+		}
+	}
+	return field.Invalid(notificationsField, "notificationsBusInstance", "notificationsBusInstance must match an existing RabbitMQ instance name")
+}