@Override
  public boolean createAmbariIdentities(Map<String, String> kerberosEnvProperties) {
    return (kerberosEnvProperties == null) || !"false".equalsIgnoreCase(kerberosEnvProperties.get(CREATE_AMBARI_PRINCIPAL));
  }
Find the {@link ServiceComponentHost}s for the cluster, filtering using the
supplied "should include" command (<code>shouldIncludeCommand</code>).
<p>
If <code>shouldIncludeCommand</code> is <code>null/code>, no filtering will be performed causing
all found {@link ServiceComponentHost}s to be returned.

@param cluster              the cluster
@param shouldIncludeCommand the filtering logic
@return a list of (filtered) {@link ServiceComponentHost}s
@throws AmbariException if an error occurs
ambari-server/src/main/java/org/apache/ambari/server/controller/KerberosHelperImpl.java