public String getFullyQualifiedServicePrincipal(String shortUserName) {
    return getServicePrincipalForUser(shortUserName) + "@" + miniKdc.getRealm();
  }
Login the given principal, using corresponding keytab file from internal map
@param principal
@return
@throws Exception
itests/hive-minikdc/src/test/java/org/apache/hive/minikdc/MiniHiveKdc.java