code: func (a *Plugin) webhookError(pod *api.Pod, attributes admission.Attributes, err error) error {
  	if err != nil {
  		klog.V(2).Infof("error contacting webhook backend: %s", err)
  		if a.defaultAllow {
  			attributes.AddAnnotation(AuditKeyPrefix+ImagePolicyFailedOpenKeySuffix, "true")
  			// TODO(wteiken): Remove the annotation code for the 1.13 release
  			annotations := pod.GetAnnotations()
  			if annotations == nil {
  				annotations = make(map[string]string)
  			}
  			annotations[api.ImagePolicyFailedOpenKey] = "true"
  			pod.ObjectMeta.SetAnnotations(annotations)
  
  			klog.V(2).Infof("resource allowed in spite of webhook backend failure")
  			return nil
  		}
  		klog.V(2).Infof("resource not allowed due to webhook backend failure ")
  		return admission.NewForbidden(attributes, err)
  	}
  	return nil
  }
docs: // Function to call on webhook failure; behavior determined by defaultAllow flag