@Override
    public String updateForClusterCreate(String propertyName,
                                         String origValue,
                                         Map<String, Map<String, String>> properties,
                                         ClusterTopology topology) {

      if (!origValue.contains("%HOSTGROUP") && (!origValue.contains(LOCALHOST))) {
        // this property must contain FQDNs specified directly by the user
        // of the Blueprint, so the processor should not attempt to update them
        return origValue;
      }

      Collection<String> hostStrings = getHostStrings(origValue, topology);
      hostStrings.addAll(getHostStringsFromLocalhost(origValue, topology));

      return resolveHostGroupPlaceholder(origValue, hostStrings);
    }
Update all host names included in the original property value with new host names which run the associated
component.

@param propertyName property name
@param origValue    original value of property
@param properties   all properties
@param topology     cluster topology
@return updated property value with old host names replaced by new host names
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/BlueprintConfigurationProcessor.java