### Volumes
* StorageClass pre-installed and set as default on Azure, AWS, GCE, OpenStack, and vSphere.
  * This is something to pay close attention to if you’ve been using Kubernetes for a while, because it changes the default behavior of PersistentVolumeClaim objects on these clouds.

  //
  // Required, must not be nil.
  optional PersistentVolumeClaimTemplate volumeClaimTemplate = 1;
}

// Event is a report of an event somewhere in the cluster.  Events
// have a limited retention time and triggers and messages may evolve
// with time.  Event consumers should not rely on the timing of an event
// with a given Reason reflecting a consistent underlying trigger, or the