// +optional
  optional string hostname = 16;

  // If specified, the fully qualified Pod hostname will be "<hostname>.<subdomain>.<pod namespace>.svc.<cluster domain>".
  // If not specified, the pod will not have a domainname at all.
  // +optional
  optional string subdomain = 17;

  // If specified, the pod's scheduling constraints
  // +optional
  optional Affinity affinity = 18;