However, while we chose to use the xDS *transport protocol*, we chose to not use the xDS resource types, such as Clusters and Listeners.
In our experience and testing, these types force us to represent data in inefficient ways because they are general purpose.
Ztunnel is not general purpose; it has an extremely tight goal.

  // rule is the strategy that will dictate what FSGroup is used in the SecurityContext.
  // +optional
  optional string rule = 1;

  // ranges are the allowed ranges of fs groups.  If you would like to force a single
  // fs group then supply a single range with the same start and end. Required for MustRunAs.
  // +optional
  repeated IDRange ranges = 2;
}