@Override
  public RequestStageContainer ensureIdentities(Cluster cluster, Map<String, ? extends Collection<String>> serviceComponentFilter,
                                                Set<String> hostFilter, Collection<String> identityFilter, Set<String> hostsToForceKerberosOperations,
                                                RequestStageContainer requestStageContainer, Boolean manageIdentities)
    throws AmbariException, KerberosOperationException {
    return handle(cluster,
        getKerberosDetails(cluster, manageIdentities),
        serviceComponentFilter,
        hostFilter,
        identityFilter,
        hostsToForceKerberosOperations,
        requestStageContainer,
        new CreatePrincipalsAndKeytabsHandler(KerberosServerAction.OperationType.DEFAULT,
            UpdateConfigurationPolicy.NONE,
            false,
            false));
  }
Parsing 'Kerberos/components' property to get list of components for 'regenerate_keytabs' request.
Must be a comma separated list of strings that follow pattern 'SERVICENAME:COMPONENTNAME;ANOTHERCOMPONENTNAME'.
For example: HDFS:NAMENODE;DATANODE,YARN:RESOURCEMANAGER,ZOOKEEPER:ZOOKEEPER_SERVER;ZOOKEEPER_CLIENT.
Absent or miss-spelled components and services must be silently ignored by caller code.

@param requestProperties
@return
ambari-server/src/main/java/org/apache/ambari/server/controller/KerberosHelperImpl.java