ambari-server/src/main/java/org/apache/ambari/server/controller/internal/ExportBlueprintRequest.java - ambari - Git at Google

 /**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License.  You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distribut
  * ed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package org.apache.ambari.server.controller.internal;

 import org.apache.ambari.server.AmbariException;
 import org.apache.ambari.server.api.util.TreeNode;
 import org.apache.ambari.server.controller.AmbariManagementController;
 import org.apache.ambari.server.controller.AmbariServer;
 import org.apache.ambari.server.controller.spi.Resource;
 import org.apache.ambari.server.controller.utilities.PropertyHelper;
 import org.apache.ambari.server.state.DesiredConfig;
 import org.apache.ambari.server.state.HostConfig;
 import org.apache.ambari.server.topology.Blueprint;
 import org.apache.ambari.server.topology.BlueprintImpl;
 import org.apache.ambari.server.topology.Component;
 import org.apache.ambari.server.topology.Configuration;
 import org.apache.ambari.server.topology.HostGroup;
 import org.apache.ambari.server.topology.HostGroupImpl;
 import org.apache.ambari.server.topology.HostGroupInfo;
 import org.apache.ambari.server.topology.InvalidTopologyTemplateException;
 import org.apache.ambari.server.topology.TopologyRequest;
 import org.apache.ambari.server.topology.TopologyValidator;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;

 /**
  * Request to export a blueprint from an existing cluster.
  */
 public class ExportBlueprintRequest implements TopologyRequest {

   private final static Logger LOG = LoggerFactory.getLogger(ExportBlueprintRequest.class);
   private static AmbariManagementController controller = AmbariServer.getController();

   private String clusterName;
   private Long clusterId;
   private Blueprint blueprint;
   private Configuration configuration;
   //todo: Should this map be represented by a new class?
   private Map<String, HostGroupInfo> hostGroupInfo = new HashMap<String, HostGroupInfo>();


   public ExportBlueprintRequest(TreeNode<Resource> clusterNode) throws InvalidTopologyTemplateException {
     Resource clusterResource = clusterNode.getObject();
     clusterName = String.valueOf(clusterResource.getPropertyValue(
         ClusterResourceProvider.CLUSTER_NAME_PROPERTY_ID));
     clusterId = Long.valueOf(String.valueOf(clusterResource.getPropertyValue(
             ClusterResourceProvider.CLUSTER_ID_PROPERTY_ID)));


     createConfiguration(clusterNode);
     //todo: should be parsing Configuration from the beginning
     //createConfiguration(configurations);

     Collection<ExportedHostGroup> exportedHostGroups = processHostGroups(clusterNode.getChild("hosts"));
     createHostGroupInfo(exportedHostGroups);
     createBlueprint(exportedHostGroups, parseStack(clusterResource));
   }

   public String getClusterName() {
     return clusterName;
   }

   @Override
   public Long getClusterId() {
     return clusterId;
   }

   @Override
   public Type getType() {
     return Type.EXPORT;
   }

   @Override
   public Blueprint getBlueprint() {
     return blueprint;
   }

   @Override
   public Configuration getConfiguration() {
     return configuration;
   }

   @Override
   public Map<String, HostGroupInfo> getHostGroupInfo() {
     return hostGroupInfo;
   }

   @Override
   public List<TopologyValidator> getTopologyValidators() {
     return Collections.emptyList();
   }

   @Override
   public String getDescription() {
     return String.format("Export Command For Cluster '%s'", clusterName);
   }

   // ----- private instance methods ------------------------------------------


   private void createBlueprint(Collection<ExportedHostGroup> exportedHostGroups, Stack stack) {
     String bpName = "exported-blueprint";

     Collection<HostGroup> hostGroups = new ArrayList<HostGroup>();
     for (ExportedHostGroup exportedHostGroup : exportedHostGroups) {

       // create Component using component name
       List<Component> componentList = new ArrayList<Component>();
       for (String component : exportedHostGroup.getComponents()) {
         componentList.add(new Component(component));
       }

       hostGroups.add(new HostGroupImpl(exportedHostGroup.getName(), bpName, stack, componentList,
           exportedHostGroup.getConfiguration(), String.valueOf(exportedHostGroup.getCardinality())));
     }
     blueprint = new BlueprintImpl(bpName, hostGroups, stack, configuration, null);
   }

   private void createHostGroupInfo(Collection<ExportedHostGroup> exportedHostGroups) {
     for (ExportedHostGroup exportedGroup : exportedHostGroups) {
       HostGroupInfo groupInfo = new HostGroupInfo(exportedGroup.getName());
       groupInfo.addHosts(exportedGroup.getHostInfo());
       //todo: should be parsing Configuration from the beginning
       groupInfo.setConfiguration(exportedGroup.getConfiguration());
       hostGroupInfo.put(groupInfo.getHostGroupName(), groupInfo);
     }
   }


   private Stack parseStack(Resource clusterResource) throws InvalidTopologyTemplateException {
     String[] stackTokens = String.valueOf(clusterResource.getPropertyValue(
         ClusterResourceProvider.CLUSTER_VERSION_PROPERTY_ID)).split("-");

     try {
       return new Stack(stackTokens[0], stackTokens[1], controller);
     } catch (AmbariException e) {
       throw new InvalidTopologyTemplateException(String.format(
           "The specified stack doesn't exist: name=%s version=%s", stackTokens[0], stackTokens[1]));
     }
   }

   /**
    * Process cluster scoped configurations.
    *
    * @param clusterNode  cluster node
    *
    */
   private void createConfiguration(TreeNode<Resource> clusterNode) {

     Map<String, Map<String, String>> properties = new HashMap<String, Map<String, String>>();
     Map<String, Map<String, Map<String, String>>> attributes = new HashMap<String, Map<String, Map<String, String>>>();

     Map<String, Object> desiredConfigMap = clusterNode.getObject().getPropertiesMap().get("Clusters/desired_configs");
     TreeNode<Resource> configNode = clusterNode.getChild("configurations");
     for (TreeNode<Resource> config : configNode.getChildren()) {
       ExportedConfiguration configuration = new ExportedConfiguration(config);
       DesiredConfig desiredConfig = (DesiredConfig) desiredConfigMap.get(configuration.getType());
       if (desiredConfig != null && desiredConfig.getTag().equals(configuration.getTag())) {

         properties.put(configuration.getType(), configuration.getProperties());
         attributes.put(configuration.getType(), configuration.getPropertyAttributes());
       }
     }
     configuration = new Configuration(properties, attributes);
     // empty parent configuration when exporting as all properties are included in this configuration
     configuration.setParentConfiguration(new Configuration(
         Collections.<String, Map<String, String>>emptyMap(),
         Collections.<String, Map<String, Map<String, String>>>emptyMap()));
   }

   /**
    * Process cluster host groups.
    *
    * @param hostNode  host node
    *
    * @return collection of host groups
    */
   private Collection<ExportedHostGroup> processHostGroups(TreeNode<Resource> hostNode) {
     Map<ExportedHostGroup, ExportedHostGroup> mapHostGroups = new HashMap<ExportedHostGroup, ExportedHostGroup>();
     int count = 1;
     for (TreeNode<Resource> host : hostNode.getChildren()) {
       ExportedHostGroup group = new ExportedHostGroup(host);
       String hostName = (String) host.getObject().getPropertyValue(
           PropertyHelper.getPropertyId("Hosts", "host_name"));

       if (mapHostGroups.containsKey(group)) {
         ExportedHostGroup hostGroup = mapHostGroups.get(group);
         hostGroup.incrementCardinality();
         hostGroup.addHost(hostName);
       } else {
         mapHostGroups.put(group, group);
         group.setName("host_group_" + count++);
         group.addHost(hostName);
       }
       processHostGroupComponents(group);
     }

     return mapHostGroups.values();
   }


   /**
    * Process host group component information for a specific host.
    *
    * @param group host group instance
    *
    * @return list of component names for the host
    */
   private List<Map<String, String>> processHostGroupComponents(ExportedHostGroup group) {
     List<Map<String, String>> listHostGroupComponents = new ArrayList<Map<String, String>>();
     for (String component : group.getComponents()) {
       Map<String, String> mapComponentProperties = new HashMap<String, String>();
       listHostGroupComponents.add(mapComponentProperties);
       mapComponentProperties.put("name", component);
     }
     return listHostGroupComponents;
   }


   // ----- Host Group inner class --------------------------------------------

   /**
    * Host Group representation.
    */
   public class ExportedHostGroup {

     /**
      * Host Group name.
      *
      */
     private String name;

     /**
      * Associated components.
      */
     private Set<String> components = new HashSet<String>();

     /**
      * Host group scoped configurations.
      */
     private Collection<ExportedConfiguration> configurations = new HashSet<ExportedConfiguration>();

     /**
      * Number of instances.
      */
     private int m_cardinality = 1;

     /**
      * Collection of associated hosts.
      */
     private Collection<String> hosts = new HashSet<String>();

     /**
      * Constructor.
      *
      * @param host  host node
      */
     public ExportedHostGroup(TreeNode<Resource> host) {
       TreeNode<Resource> components = host.getChild("host_components");
       for (TreeNode<Resource> component : components.getChildren()) {
         getComponents().add((String) component.getObject().getPropertyValue(
             "HostRoles/component_name"));
       }
       addAmbariComponentIfLocalhost((String) host.getObject().getPropertyValue(
           PropertyHelper.getPropertyId("Hosts", "host_name")));

       processGroupConfiguration(host);
     }

     public Configuration getConfiguration() {
       Map<String, Map<String, String>> configProperties = new HashMap<String, Map<String, String>>();
       Map<String, Map<String, Map<String, String>>> configAttributes = new HashMap<String, Map<String, Map<String, String>>>();

       for (ExportedConfiguration config : configurations) {
         configProperties.put(config.getType(), config.getProperties());
         configAttributes.put(config.getType(), config.getPropertyAttributes());
       }

       return new Configuration(configProperties, configAttributes);
     }

     /**
      * Process host group configuration.
      *
      * @param host  host node
      */
     private void processGroupConfiguration(TreeNode<Resource> host) {
       Map<String, Object> desiredConfigMap = host.getObject().getPropertiesMap().get("Hosts/desired_configs");
       if (desiredConfigMap != null) {
         for (Map.Entry<String, Object> entry : desiredConfigMap.entrySet()) {
           String type = entry.getKey();
           HostConfig hostConfig = (HostConfig) entry.getValue();
           Map<Long, String> overrides = hostConfig.getConfigGroupOverrides();

           if (overrides != null && ! overrides.isEmpty()) {
             Long version = Collections.max(overrides.keySet());
             String tag = overrides.get(version);
             TreeNode<Resource> clusterNode = host.getParent().getParent();
             TreeNode<Resource> configNode = clusterNode.getChild("configurations");
             for (TreeNode<Resource> config : configNode.getChildren()) {
               ExportedConfiguration configuration = new ExportedConfiguration(config);
               if (type.equals(configuration.getType()) && tag.equals(configuration.getTag())) {
                 getConfigurations().add(configuration);
                 break;
               }
             }
           }
         }
       }
     }

     public String getName() {
       return name;
     }

     public Set<String> getComponents() {
       return components;
     }

     public Collection<String> getHostInfo() {
       return hosts;
     }


     /**
      * Set the name.
      *
      * @param  name name of host group
      */
     public void setName(String name) {
       this.name = name;
     }

     /**
      * Add a host.
      *
      * @param host  host to add
      */
     public void addHost(String host) {
       hosts.add(host);
     }

     /**
      * Obtain associated host group scoped configurations.
      *
      * @return collection of host group scoped configurations
      */
     public Collection<ExportedConfiguration> getConfigurations() {
       return configurations;
     }

     /**
      * Obtain the number of instances associated with this host group.
      *
      * @return number of hosts associated with this host group
      */
     public int getCardinality() {
       return m_cardinality;
     }

     /**
      * Increment the cardinality count by one.
      */
     public void incrementCardinality() {
       m_cardinality += 1;
     }

     /**
      * Add the AMBARI_SERVER component if the host is the local host.
      *
      * @param hostname  host to check
      */
     private void addAmbariComponentIfLocalhost(String hostname) {
       try {
         InetAddress hostAddress = InetAddress.getByName(hostname);
         try {
           if (hostAddress.equals(InetAddress.getLocalHost())) {
             getComponents().add("AMBARI_SERVER");
           }
         } catch (UnknownHostException e) {
           //todo: SystemException?
           throw new RuntimeException("Unable to obtain local host name", e);
         }
       } catch (UnknownHostException e) {
         // ignore
       }
     }

     @Override
     public boolean equals(Object o) {
       if (this == o) return true;
       if (o == null || getClass() != o.getClass()) return false;

       ExportedHostGroup hostGroup = (ExportedHostGroup) o;

       return components.equals(hostGroup.components) &&
           configurations.equals(hostGroup.configurations);
     }

     @Override
     public int hashCode() {
       int result = components.hashCode();
       result = 31 * result + configurations.hashCode();
       return result;
     }
   }

   /**
    * Encapsulates a configuration.
    */
   private class ExportedConfiguration {
     /**
      * Configuration type such as hdfs-site.
      */
     private String type;

     /**
      * Configuration tag.
      */
     private String tag;

     /**
      * Properties of the configuration.
      */
     private Map<String, String> properties = new HashMap<String, String>();

     /**
      * Attributes for the properties in the cluster configuration.
      */
     private Map<String, Map<String, String>> propertyAttributes = new HashMap<String, Map<String, String>>();

     /**
      * Constructor.
      *
      * @param configNode  configuration node
      */
     @SuppressWarnings("unchecked")
     public ExportedConfiguration(TreeNode<Resource> configNode) {
       Resource configResource = configNode.getObject();
       type = (String) configResource.getPropertyValue("type");
       tag  = (String) configResource.getPropertyValue("tag");

       // property map type is currently <String, Object>
       Map<String, Map<String, Object>> propertiesMap = configNode.getObject().getPropertiesMap();
       if (propertiesMap.containsKey("properties")) {
         properties = (Map) propertiesMap.get("properties");
       }

       // get the property attributes set in this configuration
       if (propertiesMap.containsKey("properties_attributes")) {
         propertyAttributes = (Map) propertiesMap.get("properties_attributes");
       }

       //todo: not processing config here, ensure that
       //todo: this logic regarding null/empty properties is properly handled
 //      if (properties != null && !properties.isEmpty()) {
 //        stripRequiredProperties(properties);
 //      } else {
 //        LOG.warn("Empty configuration found for configuration type = " + type +
 //            " during Blueprint export.  This may occur after an upgrade of Ambari, when" +
 //            "attempting to export a Blueprint from a cluster started by an older version of " +
 //            "Ambari.");
 //      }

     }

     /**
      * Get configuration type.
      *
      * @return configuration type
      */
     public String getType() {
       return type;
     }

     /**
      * Get configuration tag.
      *
      * @return configuration tag
      */
     public String getTag() {
       return tag;
     }

     /**
      * Get configuration properties.
      *
      * @return map of properties and values
      */
     public Map<String, String> getProperties() {
       return properties;
     }

     /**
      * Get property attributes.
      *
      * @return map of property attributes
      */
     public Map<String, Map<String, String>> getPropertyAttributes() {
       return propertyAttributes;
     }

     @Override
     public boolean equals(Object o) {
       if (this == o) return true;
       if (o == null || getClass() != o.getClass()) return false;

       ExportedConfiguration that = (ExportedConfiguration) o;
       return tag.equals(that.tag) && type.equals(that.type) && properties.equals(that.properties)
           && propertyAttributes.equals(that.propertyAttributes);
     }

     @Override
     public int hashCode() {
       int result = type.hashCode();
       result = 31 * result + tag.hashCode();
       result = 31 * result + properties.hashCode();
       result = 31 * result + propertyAttributes.hashCode();
       return result;
     }
   }
 }
	/**
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distribut
	* ed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package org.apache.ambari.server.controller.internal;

	import org.apache.ambari.server.AmbariException;
	import org.apache.ambari.server.api.util.TreeNode;
	import org.apache.ambari.server.controller.AmbariManagementController;
	import org.apache.ambari.server.controller.AmbariServer;
	import org.apache.ambari.server.controller.spi.Resource;
	import org.apache.ambari.server.controller.utilities.PropertyHelper;
	import org.apache.ambari.server.state.DesiredConfig;
	import org.apache.ambari.server.state.HostConfig;
	import org.apache.ambari.server.topology.Blueprint;
	import org.apache.ambari.server.topology.BlueprintImpl;
	import org.apache.ambari.server.topology.Component;
	import org.apache.ambari.server.topology.Configuration;
	import org.apache.ambari.server.topology.HostGroup;
	import org.apache.ambari.server.topology.HostGroupImpl;
	import org.apache.ambari.server.topology.HostGroupInfo;
	import org.apache.ambari.server.topology.InvalidTopologyTemplateException;
	import org.apache.ambari.server.topology.TopologyRequest;
	import org.apache.ambari.server.topology.TopologyValidator;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import java.net.InetAddress;
	import java.net.UnknownHostException;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;

	/**
	* Request to export a blueprint from an existing cluster.
	*/
	public class ExportBlueprintRequest implements TopologyRequest {

	private final static Logger LOG = LoggerFactory.getLogger(ExportBlueprintRequest.class);
	private static AmbariManagementController controller = AmbariServer.getController();

	private String clusterName;
	private Long clusterId;
	private Blueprint blueprint;
	private Configuration configuration;
	//todo: Should this map be represented by a new class?
	private Map<String, HostGroupInfo> hostGroupInfo = new HashMap<String, HostGroupInfo>();


	public ExportBlueprintRequest(TreeNode<Resource> clusterNode) throws InvalidTopologyTemplateException {
	Resource clusterResource = clusterNode.getObject();
	clusterName = String.valueOf(clusterResource.getPropertyValue(
	ClusterResourceProvider.CLUSTER_NAME_PROPERTY_ID));
	clusterId = Long.valueOf(String.valueOf(clusterResource.getPropertyValue(
	ClusterResourceProvider.CLUSTER_ID_PROPERTY_ID)));


	createConfiguration(clusterNode);
	//todo: should be parsing Configuration from the beginning
	//createConfiguration(configurations);

	Collection<ExportedHostGroup> exportedHostGroups = processHostGroups(clusterNode.getChild("hosts"));
	createHostGroupInfo(exportedHostGroups);
	createBlueprint(exportedHostGroups, parseStack(clusterResource));
	}

	public String getClusterName() {
	return clusterName;
	}

	@Override
	public Long getClusterId() {
	return clusterId;
	}

	@Override
	public Type getType() {
	return Type.EXPORT;
	}

	@Override
	public Blueprint getBlueprint() {
	return blueprint;
	}

	@Override
	public Configuration getConfiguration() {
	return configuration;
	}

	@Override
	public Map<String, HostGroupInfo> getHostGroupInfo() {
	return hostGroupInfo;
	}

	@Override
	public List<TopologyValidator> getTopologyValidators() {
	return Collections.emptyList();
	}

	@Override
	public String getDescription() {
	return String.format("Export Command For Cluster '%s'", clusterName);
	}

	// ----- private instance methods ------------------------------------------


	private void createBlueprint(Collection<ExportedHostGroup> exportedHostGroups, Stack stack) {
	String bpName = "exported-blueprint";

	Collection<HostGroup> hostGroups = new ArrayList<HostGroup>();
	for (ExportedHostGroup exportedHostGroup : exportedHostGroups) {

	// create Component using component name
	List<Component> componentList = new ArrayList<Component>();
	for (String component : exportedHostGroup.getComponents()) {
	componentList.add(new Component(component));
	}

	hostGroups.add(new HostGroupImpl(exportedHostGroup.getName(), bpName, stack, componentList,
	exportedHostGroup.getConfiguration(), String.valueOf(exportedHostGroup.getCardinality())));
	}
	blueprint = new BlueprintImpl(bpName, hostGroups, stack, configuration, null);
	}

	private void createHostGroupInfo(Collection<ExportedHostGroup> exportedHostGroups) {
	for (ExportedHostGroup exportedGroup : exportedHostGroups) {
	HostGroupInfo groupInfo = new HostGroupInfo(exportedGroup.getName());
	groupInfo.addHosts(exportedGroup.getHostInfo());
	//todo: should be parsing Configuration from the beginning
	groupInfo.setConfiguration(exportedGroup.getConfiguration());
	hostGroupInfo.put(groupInfo.getHostGroupName(), groupInfo);
	}
	}


	private Stack parseStack(Resource clusterResource) throws InvalidTopologyTemplateException {
	String[] stackTokens = String.valueOf(clusterResource.getPropertyValue(
	ClusterResourceProvider.CLUSTER_VERSION_PROPERTY_ID)).split("-");

	try {
	return new Stack(stackTokens[0], stackTokens[1], controller);
	} catch (AmbariException e) {
	throw new InvalidTopologyTemplateException(String.format(
	"The specified stack doesn't exist: name=%s version=%s", stackTokens[0], stackTokens[1]));
	}
	}

	/**
	* Process cluster scoped configurations.
	*
	* @param clusterNode cluster node
	*
	*/
	private void createConfiguration(TreeNode<Resource> clusterNode) {

	Map<String, Map<String, String>> properties = new HashMap<String, Map<String, String>>();
	Map<String, Map<String, Map<String, String>>> attributes = new HashMap<String, Map<String, Map<String, String>>>();

	Map<String, Object> desiredConfigMap = clusterNode.getObject().getPropertiesMap().get("Clusters/desired_configs");
	TreeNode<Resource> configNode = clusterNode.getChild("configurations");
	for (TreeNode<Resource> config : configNode.getChildren()) {
	ExportedConfiguration configuration = new ExportedConfiguration(config);
	DesiredConfig desiredConfig = (DesiredConfig) desiredConfigMap.get(configuration.getType());
	if (desiredConfig != null && desiredConfig.getTag().equals(configuration.getTag())) {

	properties.put(configuration.getType(), configuration.getProperties());
	attributes.put(configuration.getType(), configuration.getPropertyAttributes());
	}
	}
	configuration = new Configuration(properties, attributes);
	// empty parent configuration when exporting as all properties are included in this configuration
	configuration.setParentConfiguration(new Configuration(
	Collections.<String, Map<String, String>>emptyMap(),
	Collections.<String, Map<String, Map<String, String>>>emptyMap()));
	}

	/**
	* Process cluster host groups.
	*
	* @param hostNode host node
	*
	* @return collection of host groups
	*/
	private Collection<ExportedHostGroup> processHostGroups(TreeNode<Resource> hostNode) {
	Map<ExportedHostGroup, ExportedHostGroup> mapHostGroups = new HashMap<ExportedHostGroup, ExportedHostGroup>();
	int count = 1;
	for (TreeNode<Resource> host : hostNode.getChildren()) {
	ExportedHostGroup group = new ExportedHostGroup(host);
	String hostName = (String) host.getObject().getPropertyValue(
	PropertyHelper.getPropertyId("Hosts", "host_name"));

	if (mapHostGroups.containsKey(group)) {
	ExportedHostGroup hostGroup = mapHostGroups.get(group);
	hostGroup.incrementCardinality();
	hostGroup.addHost(hostName);
	} else {
	mapHostGroups.put(group, group);
	group.setName("host_group_" + count++);
	group.addHost(hostName);
	}
	processHostGroupComponents(group);
	}

	return mapHostGroups.values();
	}


	/**
	* Process host group component information for a specific host.
	*
	* @param group host group instance
	*
	* @return list of component names for the host
	*/
	private List<Map<String, String>> processHostGroupComponents(ExportedHostGroup group) {
	List<Map<String, String>> listHostGroupComponents = new ArrayList<Map<String, String>>();
	for (String component : group.getComponents()) {
	Map<String, String> mapComponentProperties = new HashMap<String, String>();
	listHostGroupComponents.add(mapComponentProperties);
	mapComponentProperties.put("name", component);
	}
	return listHostGroupComponents;
	}


	// ----- Host Group inner class --------------------------------------------

	/**
	* Host Group representation.
	*/
	public class ExportedHostGroup {

	/**
	* Host Group name.
	*
	*/
	private String name;

	/**
	* Associated components.
	*/
	private Set<String> components = new HashSet<String>();

	/**
	* Host group scoped configurations.
	*/
	private Collection<ExportedConfiguration> configurations = new HashSet<ExportedConfiguration>();

	/**
	* Number of instances.
	*/
	private int m_cardinality = 1;

	/**
	* Collection of associated hosts.
	*/
	private Collection<String> hosts = new HashSet<String>();

	/**
	* Constructor.
	*
	* @param host host node
	*/
	public ExportedHostGroup(TreeNode<Resource> host) {
	TreeNode<Resource> components = host.getChild("host_components");
	for (TreeNode<Resource> component : components.getChildren()) {
	getComponents().add((String) component.getObject().getPropertyValue(
	"HostRoles/component_name"));
	}
	addAmbariComponentIfLocalhost((String) host.getObject().getPropertyValue(
	PropertyHelper.getPropertyId("Hosts", "host_name")));

	processGroupConfiguration(host);
	}

	public Configuration getConfiguration() {
	Map<String, Map<String, String>> configProperties = new HashMap<String, Map<String, String>>();
	Map<String, Map<String, Map<String, String>>> configAttributes = new HashMap<String, Map<String, Map<String, String>>>();

	for (ExportedConfiguration config : configurations) {
	configProperties.put(config.getType(), config.getProperties());
	configAttributes.put(config.getType(), config.getPropertyAttributes());
	}

	return new Configuration(configProperties, configAttributes);
	}

	/**
	* Process host group configuration.
	*
	* @param host host node
	*/
	private void processGroupConfiguration(TreeNode<Resource> host) {
	Map<String, Object> desiredConfigMap = host.getObject().getPropertiesMap().get("Hosts/desired_configs");
	if (desiredConfigMap != null) {
	for (Map.Entry<String, Object> entry : desiredConfigMap.entrySet()) {
	String type = entry.getKey();
	HostConfig hostConfig = (HostConfig) entry.getValue();
	Map<Long, String> overrides = hostConfig.getConfigGroupOverrides();

	if (overrides != null && ! overrides.isEmpty()) {
	Long version = Collections.max(overrides.keySet());
	String tag = overrides.get(version);
	TreeNode<Resource> clusterNode = host.getParent().getParent();
	TreeNode<Resource> configNode = clusterNode.getChild("configurations");
	for (TreeNode<Resource> config : configNode.getChildren()) {
	ExportedConfiguration configuration = new ExportedConfiguration(config);
	if (type.equals(configuration.getType()) && tag.equals(configuration.getTag())) {
	getConfigurations().add(configuration);
	break;
	}
	}
	}
	}
	}
	}

	public String getName() {
	return name;
	}

	public Set<String> getComponents() {
	return components;
	}

	public Collection<String> getHostInfo() {
	return hosts;
	}


	/**
	* Set the name.
	*
	* @param name name of host group
	*/
	public void setName(String name) {
	this.name = name;
	}

	/**
	* Add a host.
	*
	* @param host host to add
	*/
	public void addHost(String host) {
	hosts.add(host);
	}

	/**
	* Obtain associated host group scoped configurations.
	*
	* @return collection of host group scoped configurations
	*/
	public Collection<ExportedConfiguration> getConfigurations() {
	return configurations;
	}

	/**
	* Obtain the number of instances associated with this host group.
	*
	* @return number of hosts associated with this host group
	*/
	public int getCardinality() {
	return m_cardinality;
	}

	/**
	* Increment the cardinality count by one.
	*/
	public void incrementCardinality() {
	m_cardinality += 1;
	}

	/**
	* Add the AMBARI_SERVER component if the host is the local host.
	*
	* @param hostname host to check
	*/
	private void addAmbariComponentIfLocalhost(String hostname) {
	try {
	InetAddress hostAddress = InetAddress.getByName(hostname);
	try {
	if (hostAddress.equals(InetAddress.getLocalHost())) {
	getComponents().add("AMBARI_SERVER");
	}
	} catch (UnknownHostException e) {
	//todo: SystemException?
	throw new RuntimeException("Unable to obtain local host name", e);
	}
	} catch (UnknownHostException e) {
	// ignore
	}
	}

	@Override
	public boolean equals(Object o) {
	if (this == o) return true;
	if (o == null \|\| getClass() != o.getClass()) return false;

	ExportedHostGroup hostGroup = (ExportedHostGroup) o;

	return components.equals(hostGroup.components) &&
	configurations.equals(hostGroup.configurations);
	}

	@Override
	public int hashCode() {
	int result = components.hashCode();
	result = 31 * result + configurations.hashCode();
	return result;
	}
	}

	/**
	* Encapsulates a configuration.
	*/
	private class ExportedConfiguration {
	/**
	* Configuration type such as hdfs-site.
	*/
	private String type;

	/**
	* Configuration tag.
	*/
	private String tag;

	/**
	* Properties of the configuration.
	*/
	private Map<String, String> properties = new HashMap<String, String>();

	/**
	* Attributes for the properties in the cluster configuration.
	*/
	private Map<String, Map<String, String>> propertyAttributes = new HashMap<String, Map<String, String>>();

	/**
	* Constructor.
	*
	* @param configNode configuration node
	*/
	@SuppressWarnings("unchecked")
	public ExportedConfiguration(TreeNode<Resource> configNode) {
	Resource configResource = configNode.getObject();
	type = (String) configResource.getPropertyValue("type");
	tag = (String) configResource.getPropertyValue("tag");

	// property map type is currently <String, Object>
	Map<String, Map<String, Object>> propertiesMap = configNode.getObject().getPropertiesMap();
	if (propertiesMap.containsKey("properties")) {
	properties = (Map) propertiesMap.get("properties");
	}

	// get the property attributes set in this configuration
	if (propertiesMap.containsKey("properties_attributes")) {
	propertyAttributes = (Map) propertiesMap.get("properties_attributes");
	}

	//todo: not processing config here, ensure that
	//todo: this logic regarding null/empty properties is properly handled
	// if (properties != null && !properties.isEmpty()) {
	// stripRequiredProperties(properties);
	// } else {
	// LOG.warn("Empty configuration found for configuration type = " + type +
	// " during Blueprint export. This may occur after an upgrade of Ambari, when" +
	// "attempting to export a Blueprint from a cluster started by an older version of " +
	// "Ambari.");
	// }

	}

	/**
	* Get configuration type.
	*
	* @return configuration type
	*/
	public String getType() {
	return type;
	}

	/**
	* Get configuration tag.
	*
	* @return configuration tag
	*/
	public String getTag() {
	return tag;
	}

	/**
	* Get configuration properties.
	*
	* @return map of properties and values
	*/
	public Map<String, String> getProperties() {
	return properties;
	}

	/**
	* Get property attributes.
	*
	* @return map of property attributes
	*/
	public Map<String, Map<String, String>> getPropertyAttributes() {
	return propertyAttributes;
	}

	@Override
	public boolean equals(Object o) {
	if (this == o) return true;
	if (o == null \|\| getClass() != o.getClass()) return false;

	ExportedConfiguration that = (ExportedConfiguration) o;
	return tag.equals(that.tag) && type.equals(that.type) && properties.equals(that.properties)
	&& propertyAttributes.equals(that.propertyAttributes);
	}

	@Override
	public int hashCode() {
	int result = type.hashCode();
	result = 31 * result + tag.hashCode();
	result = 31 * result + properties.hashCode();
	result = 31 * result + propertyAttributes.hashCode();
	return result;
	}
	}
	}