hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azure/RemoteSASKeyGeneratorImpl.java - hadoop - 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 distributed 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.hadoop.fs.azure;

 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.List;
 import java.util.concurrent.TimeUnit;

 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.azure.security.Constants;
 import org.apache.hadoop.io.retry.RetryPolicy;
 import org.apache.hadoop.io.retry.RetryUtils;
 import org.apache.hadoop.security.UserGroupInformation;

 import org.apache.http.NameValuePair;
 import org.apache.http.client.methods.HttpGet;
 import org.apache.http.client.utils.URIBuilder;
 import org.codehaus.jackson.JsonParseException;
 import org.codehaus.jackson.map.JsonMappingException;
 import org.codehaus.jackson.map.ObjectMapper;

 import org.codehaus.jackson.map.ObjectReader;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 import static org.apache.hadoop.fs.azure.WasbRemoteCallHelper.REMOTE_CALL_SUCCESS_CODE;

 /**
  * Class implementing a RemoteSASKeyGenerator. This class
  * uses the url passed in via the Configuration to make a
  * rest call to generate the required SAS Key.
  */
 public class RemoteSASKeyGeneratorImpl extends SASKeyGeneratorImpl {

   public static final Logger LOG =
       LoggerFactory.getLogger(AzureNativeFileSystemStore.class);
   private static final ObjectReader RESPONSE_READER = new ObjectMapper()
       .reader(RemoteSASKeyGenerationResponse.class);

   /**
    * Configuration parameter name expected in the Configuration
    * object to provide the url of the remote service {@value}
    */
   public static final String KEY_CRED_SERVICE_URLS =
       "fs.azure.cred.service.urls";
   /**
    * Configuration key to enable http retry policy for SAS Key generation. {@value}
    */
   public static final String
       SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_ENABLED_KEY =
       "fs.azure.saskeygenerator.http.retry.policy.enabled";
   /**
    * Configuration key for SAS Key Generation http retry policy spec. {@value}
    */
   public static final String
       SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_KEY =
       "fs.azure.saskeygenerator.http.retry.policy.spec";
   /**
    * Container SAS Key generation OP name. {@value}
    */
   private static final String CONTAINER_SAS_OP = "GET_CONTAINER_SAS";
   /**
    * Relative Blob SAS Key generation OP name. {@value}
    */
   private static final String BLOB_SAS_OP = "GET_RELATIVE_BLOB_SAS";
   /**
    * Query parameter specifying the expiry period to be used for sas key
    * {@value}
    */
   private static final String SAS_EXPIRY_QUERY_PARAM_NAME = "sas_expiry";
   /**
    * Query parameter name for the storage account. {@value}
    */
   private static final String STORAGE_ACCOUNT_QUERY_PARAM_NAME =
       "storage_account";
   /**
    * Query parameter name for the storage account container. {@value}
    */
   private static final String CONTAINER_QUERY_PARAM_NAME = "container";
   /**
    * Query parameter name for the relative path inside the storage
    * account container. {@value}
    */
   private static final String RELATIVE_PATH_QUERY_PARAM_NAME = "relative_path";
   /**
    * SAS Key Generation Remote http client retry policy spec. {@value}
    */
   private static final String
       SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_DEFAULT =
       "10,3,100,2";
   /**
    * Saskey caching period
    */
   private static final String SASKEY_CACHEENTRY_EXPIRY_PERIOD =
       "fs.azure.saskey.cacheentry.expiry.period";

   private WasbRemoteCallHelper remoteCallHelper = null;
   private boolean isKerberosSupportEnabled;
   private boolean isSpnegoTokenCacheEnabled;
   private RetryPolicy retryPolicy;
   private String[] commaSeparatedUrls;
   private CachingAuthorizer<CachedSASKeyEntry, URI> cache;

   private static final int HOURS_IN_DAY = 24;
   private static final int MINUTES_IN_HOUR = 60;

   public RemoteSASKeyGeneratorImpl(Configuration conf) {
     super(conf);
   }

   public void initialize(Configuration conf) throws IOException {

     LOG.debug("Initializing RemoteSASKeyGeneratorImpl instance");

     this.retryPolicy = RetryUtils.getMultipleLinearRandomRetry(conf,
         SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_ENABLED_KEY, true,
         SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_KEY,
         SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_DEFAULT);

     this.isKerberosSupportEnabled =
         conf.getBoolean(Constants.AZURE_KERBEROS_SUPPORT_PROPERTY_NAME, false);
     this.isSpnegoTokenCacheEnabled =
         conf.getBoolean(Constants.AZURE_ENABLE_SPNEGO_TOKEN_CACHE, true);
     this.commaSeparatedUrls = conf.getTrimmedStrings(KEY_CRED_SERVICE_URLS);
     if (this.commaSeparatedUrls == null || this.commaSeparatedUrls.length <= 0) {
       throw new IOException(
           KEY_CRED_SERVICE_URLS + " config not set" + " in configuration.");
     }
     if (isKerberosSupportEnabled && UserGroupInformation.isSecurityEnabled()) {
       this.remoteCallHelper = new SecureWasbRemoteCallHelper(retryPolicy, false,
           isSpnegoTokenCacheEnabled);
     } else {
       this.remoteCallHelper = new WasbRemoteCallHelper(retryPolicy);
     }

     /* Expire the cache entry five minutes before the actual saskey expiry, so that we never encounter a case
      * where a stale sas-key-entry is picked up from the cache; which is expired on use.
      */
     long sasKeyExpiryPeriodInMinutes = getSasKeyExpiryPeriod() * HOURS_IN_DAY * MINUTES_IN_HOUR; // sas-expiry is in days, convert into mins
     long cacheEntryDurationInMinutes =
         conf.getTimeDuration(SASKEY_CACHEENTRY_EXPIRY_PERIOD, sasKeyExpiryPeriodInMinutes, TimeUnit.MINUTES);
     cacheEntryDurationInMinutes = (cacheEntryDurationInMinutes > (sasKeyExpiryPeriodInMinutes - 5))
         ? (sasKeyExpiryPeriodInMinutes - 5)
         : cacheEntryDurationInMinutes;
     this.cache = new CachingAuthorizer<>(cacheEntryDurationInMinutes, "SASKEY");
     this.cache.init(conf);
     LOG.debug("Initialization of RemoteSASKeyGenerator instance successful");
   }

   @Override
   public URI getContainerSASUri(String storageAccount,
       String container) throws SASKeyGenerationException {
     RemoteSASKeyGenerationResponse sasKeyResponse = null;
     try {
       CachedSASKeyEntry cacheKey = new CachedSASKeyEntry(storageAccount, container, "/");
       URI cacheResult = cache.get(cacheKey);
       if (cacheResult != null) {
         return cacheResult;
       }

       LOG.debug("Generating Container SAS Key: Storage Account {}, Container {}", storageAccount, container);
       URIBuilder uriBuilder = new URIBuilder();
       uriBuilder.setPath("/" + CONTAINER_SAS_OP);
       uriBuilder.addParameter(STORAGE_ACCOUNT_QUERY_PARAM_NAME, storageAccount);
       uriBuilder.addParameter(CONTAINER_QUERY_PARAM_NAME, container);
       uriBuilder.addParameter(SAS_EXPIRY_QUERY_PARAM_NAME,
           "" + getSasKeyExpiryPeriod());

       sasKeyResponse = makeRemoteRequest(commaSeparatedUrls, uriBuilder.getPath(),
               uriBuilder.getQueryParams());

       if (sasKeyResponse.getResponseCode() == REMOTE_CALL_SUCCESS_CODE) {
         URI sasKey = new URI(sasKeyResponse.getSasKey());
         cache.put(cacheKey, sasKey);
         return sasKey;
       } else {
         throw new SASKeyGenerationException(
             "Remote Service encountered error in SAS Key generation : "
                 + sasKeyResponse.getResponseMessage());
       }
     } catch (URISyntaxException uriSyntaxEx) {
       throw new SASKeyGenerationException("Encountered URISyntaxException"
           + " while building the HttpGetRequest to remote service for ",
           uriSyntaxEx);
     }
   }

   @Override
   public URI getRelativeBlobSASUri(String storageAccount,
       String container, String relativePath) throws SASKeyGenerationException {

     try {
       CachedSASKeyEntry cacheKey = new CachedSASKeyEntry(storageAccount, container, relativePath);
       URI cacheResult = cache.get(cacheKey);
       if (cacheResult != null) {
         return cacheResult;
       }

       LOG.debug("Generating RelativePath SAS Key for relativePath {} inside Container {} inside Storage Account {}",
           relativePath, container, storageAccount);

       URIBuilder uriBuilder = new URIBuilder();
       uriBuilder.setPath("/" + BLOB_SAS_OP);
       uriBuilder.addParameter(STORAGE_ACCOUNT_QUERY_PARAM_NAME, storageAccount);
       uriBuilder.addParameter(CONTAINER_QUERY_PARAM_NAME, container);
       uriBuilder.addParameter(RELATIVE_PATH_QUERY_PARAM_NAME, relativePath);
       uriBuilder.addParameter(SAS_EXPIRY_QUERY_PARAM_NAME,
           "" + getSasKeyExpiryPeriod());

       RemoteSASKeyGenerationResponse sasKeyResponse =
           makeRemoteRequest(commaSeparatedUrls, uriBuilder.getPath(),
               uriBuilder.getQueryParams());
       if (sasKeyResponse.getResponseCode() == REMOTE_CALL_SUCCESS_CODE) {
         URI sasKey = new URI(sasKeyResponse.getSasKey());
         cache.put(cacheKey, sasKey);
         return sasKey;
       } else {
         throw new SASKeyGenerationException(
             "Remote Service encountered error in SAS Key generation : "
                 + sasKeyResponse.getResponseMessage());
       }
     } catch (URISyntaxException uriSyntaxEx) {
       throw new SASKeyGenerationException("Encountered URISyntaxException"
           + " while building the HttpGetRequest to " + " remote service",
           uriSyntaxEx);
     }
   }

   /**
    * Helper method to make a remote request.
    *
    * @param urls        - Urls to use for the remote request
    * @param path        - hadoop.auth token for the remote request
    * @param queryParams - queryParams to be used.
    * @return RemoteSASKeyGenerationResponse
    */
   private RemoteSASKeyGenerationResponse makeRemoteRequest(String[] urls,
       String path, List<NameValuePair> queryParams)
       throws SASKeyGenerationException {

     try {
       String responseBody = remoteCallHelper
           .makeRemoteRequest(urls, path, queryParams, HttpGet.METHOD_NAME);
       return RESPONSE_READER.readValue(responseBody);

     } catch (WasbRemoteCallException remoteCallEx) {
       throw new SASKeyGenerationException("Encountered RemoteCallException"
           + " while retrieving SAS key from remote service", remoteCallEx);
     } catch (JsonParseException jsonParserEx) {
       throw new SASKeyGenerationException("Encountered JsonParseException "
           + "while parsing the response from remote"
           + " service into RemoteSASKeyGenerationResponse object",
           jsonParserEx);
     } catch (JsonMappingException jsonMappingEx) {
       throw new SASKeyGenerationException("Encountered JsonMappingException"
           + " while mapping the response from remote service into "
           + "RemoteSASKeyGenerationResponse object", jsonMappingEx);
     } catch (IOException ioEx) {
       throw new SASKeyGenerationException("Encountered IOException while "
           + "accessing remote service to retrieve SAS Key", ioEx);
     }
   }
 }

 /**
  * POJO representing the response expected from a Remote
  * SAS Key generation service.
  * The remote SAS Key generation service is expected to
  * return SAS key in json format:
  * {
  *   "responseCode" : 0 or non-zero <int>,
  *   "responseMessage" : relavant message on failure <String>,
  *   "sasKey" : Requested SAS Key <String>
  * }
  */
 class RemoteSASKeyGenerationResponse {

   /**
    * Response code for the call.
    */
   private int responseCode;

   /**
    * An intelligent message corresponding to
    * result. Specifically in case of failure
    * the reason for failure.
    */
   private String responseMessage;

   /**
    * SAS Key corresponding to the request.
    */
   private String sasKey;

   public int getResponseCode() {
     return responseCode;
   }

   public void setResponseCode(int responseCode) {
     this.responseCode = responseCode;
   }

   public String getResponseMessage() {
     return responseMessage;
   }

   public void setResponseMessage(String responseMessage) {
     this.responseMessage = responseMessage;
   }

   public String getSasKey() {
     return sasKey;
   }

   public void setSasKey(String sasKey) {
     this.sasKey = sasKey;
   }
 }
	/**
	* 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 distributed 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.hadoop.fs.azure;

	import java.io.IOException;
	import java.net.URI;
	import java.net.URISyntaxException;
	import java.util.List;
	import java.util.concurrent.TimeUnit;

	import org.apache.hadoop.conf.Configuration;
	import org.apache.hadoop.fs.azure.security.Constants;
	import org.apache.hadoop.io.retry.RetryPolicy;
	import org.apache.hadoop.io.retry.RetryUtils;
	import org.apache.hadoop.security.UserGroupInformation;

	import org.apache.http.NameValuePair;
	import org.apache.http.client.methods.HttpGet;
	import org.apache.http.client.utils.URIBuilder;
	import org.codehaus.jackson.JsonParseException;
	import org.codehaus.jackson.map.JsonMappingException;
	import org.codehaus.jackson.map.ObjectMapper;

	import org.codehaus.jackson.map.ObjectReader;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	import static org.apache.hadoop.fs.azure.WasbRemoteCallHelper.REMOTE_CALL_SUCCESS_CODE;

	/**
	* Class implementing a RemoteSASKeyGenerator. This class
	* uses the url passed in via the Configuration to make a
	* rest call to generate the required SAS Key.
	*/
	public class RemoteSASKeyGeneratorImpl extends SASKeyGeneratorImpl {

	public static final Logger LOG =
	LoggerFactory.getLogger(AzureNativeFileSystemStore.class);
	private static final ObjectReader RESPONSE_READER = new ObjectMapper()
	.reader(RemoteSASKeyGenerationResponse.class);

	/**
	* Configuration parameter name expected in the Configuration
	* object to provide the url of the remote service {@value}
	*/
	public static final String KEY_CRED_SERVICE_URLS =
	"fs.azure.cred.service.urls";
	/**
	* Configuration key to enable http retry policy for SAS Key generation. {@value}
	*/
	public static final String
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_ENABLED_KEY =
	"fs.azure.saskeygenerator.http.retry.policy.enabled";
	/**
	* Configuration key for SAS Key Generation http retry policy spec. {@value}
	*/
	public static final String
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_KEY =
	"fs.azure.saskeygenerator.http.retry.policy.spec";
	/**
	* Container SAS Key generation OP name. {@value}
	*/
	private static final String CONTAINER_SAS_OP = "GET_CONTAINER_SAS";
	/**
	* Relative Blob SAS Key generation OP name. {@value}
	*/
	private static final String BLOB_SAS_OP = "GET_RELATIVE_BLOB_SAS";
	/**
	* Query parameter specifying the expiry period to be used for sas key
	* {@value}
	*/
	private static final String SAS_EXPIRY_QUERY_PARAM_NAME = "sas_expiry";
	/**
	* Query parameter name for the storage account. {@value}
	*/
	private static final String STORAGE_ACCOUNT_QUERY_PARAM_NAME =
	"storage_account";
	/**
	* Query parameter name for the storage account container. {@value}
	*/
	private static final String CONTAINER_QUERY_PARAM_NAME = "container";
	/**
	* Query parameter name for the relative path inside the storage
	* account container. {@value}
	*/
	private static final String RELATIVE_PATH_QUERY_PARAM_NAME = "relative_path";
	/**
	* SAS Key Generation Remote http client retry policy spec. {@value}
	*/
	private static final String
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_DEFAULT =
	"10,3,100,2";
	/**
	* Saskey caching period
	*/
	private static final String SASKEY_CACHEENTRY_EXPIRY_PERIOD =
	"fs.azure.saskey.cacheentry.expiry.period";

	private WasbRemoteCallHelper remoteCallHelper = null;
	private boolean isKerberosSupportEnabled;
	private boolean isSpnegoTokenCacheEnabled;
	private RetryPolicy retryPolicy;
	private String[] commaSeparatedUrls;
	private CachingAuthorizer<CachedSASKeyEntry, URI> cache;

	private static final int HOURS_IN_DAY = 24;
	private static final int MINUTES_IN_HOUR = 60;

	public RemoteSASKeyGeneratorImpl(Configuration conf) {
	super(conf);
	}

	public void initialize(Configuration conf) throws IOException {

	LOG.debug("Initializing RemoteSASKeyGeneratorImpl instance");

	this.retryPolicy = RetryUtils.getMultipleLinearRandomRetry(conf,
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_ENABLED_KEY, true,
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_KEY,
	SAS_KEY_GENERATOR_HTTP_CLIENT_RETRY_POLICY_SPEC_DEFAULT);

	this.isKerberosSupportEnabled =
	conf.getBoolean(Constants.AZURE_KERBEROS_SUPPORT_PROPERTY_NAME, false);
	this.isSpnegoTokenCacheEnabled =
	conf.getBoolean(Constants.AZURE_ENABLE_SPNEGO_TOKEN_CACHE, true);
	this.commaSeparatedUrls = conf.getTrimmedStrings(KEY_CRED_SERVICE_URLS);
	if (this.commaSeparatedUrls == null \|\| this.commaSeparatedUrls.length <= 0) {
	throw new IOException(
	KEY_CRED_SERVICE_URLS + " config not set" + " in configuration.");
	}
	if (isKerberosSupportEnabled && UserGroupInformation.isSecurityEnabled()) {
	this.remoteCallHelper = new SecureWasbRemoteCallHelper(retryPolicy, false,
	isSpnegoTokenCacheEnabled);
	} else {
	this.remoteCallHelper = new WasbRemoteCallHelper(retryPolicy);
	}

	/* Expire the cache entry five minutes before the actual saskey expiry, so that we never encounter a case
	* where a stale sas-key-entry is picked up from the cache; which is expired on use.
	*/
	long sasKeyExpiryPeriodInMinutes = getSasKeyExpiryPeriod() * HOURS_IN_DAY * MINUTES_IN_HOUR; // sas-expiry is in days, convert into mins
	long cacheEntryDurationInMinutes =
	conf.getTimeDuration(SASKEY_CACHEENTRY_EXPIRY_PERIOD, sasKeyExpiryPeriodInMinutes, TimeUnit.MINUTES);
	cacheEntryDurationInMinutes = (cacheEntryDurationInMinutes > (sasKeyExpiryPeriodInMinutes - 5))
	? (sasKeyExpiryPeriodInMinutes - 5)
	: cacheEntryDurationInMinutes;
	this.cache = new CachingAuthorizer<>(cacheEntryDurationInMinutes, "SASKEY");
	this.cache.init(conf);
	LOG.debug("Initialization of RemoteSASKeyGenerator instance successful");
	}

	@Override
	public URI getContainerSASUri(String storageAccount,
	String container) throws SASKeyGenerationException {
	RemoteSASKeyGenerationResponse sasKeyResponse = null;
	try {
	CachedSASKeyEntry cacheKey = new CachedSASKeyEntry(storageAccount, container, "/");
	URI cacheResult = cache.get(cacheKey);
	if (cacheResult != null) {
	return cacheResult;
	}

	LOG.debug("Generating Container SAS Key: Storage Account {}, Container {}", storageAccount, container);
	URIBuilder uriBuilder = new URIBuilder();
	uriBuilder.setPath("/" + CONTAINER_SAS_OP);
	uriBuilder.addParameter(STORAGE_ACCOUNT_QUERY_PARAM_NAME, storageAccount);
	uriBuilder.addParameter(CONTAINER_QUERY_PARAM_NAME, container);
	uriBuilder.addParameter(SAS_EXPIRY_QUERY_PARAM_NAME,
	"" + getSasKeyExpiryPeriod());

	sasKeyResponse = makeRemoteRequest(commaSeparatedUrls, uriBuilder.getPath(),
	uriBuilder.getQueryParams());

	if (sasKeyResponse.getResponseCode() == REMOTE_CALL_SUCCESS_CODE) {
	URI sasKey = new URI(sasKeyResponse.getSasKey());
	cache.put(cacheKey, sasKey);
	return sasKey;
	} else {
	throw new SASKeyGenerationException(
	"Remote Service encountered error in SAS Key generation : "
	+ sasKeyResponse.getResponseMessage());
	}
	} catch (URISyntaxException uriSyntaxEx) {
	throw new SASKeyGenerationException("Encountered URISyntaxException"
	+ " while building the HttpGetRequest to remote service for ",
	uriSyntaxEx);
	}
	}

	@Override
	public URI getRelativeBlobSASUri(String storageAccount,
	String container, String relativePath) throws SASKeyGenerationException {

	try {
	CachedSASKeyEntry cacheKey = new CachedSASKeyEntry(storageAccount, container, relativePath);
	URI cacheResult = cache.get(cacheKey);
	if (cacheResult != null) {
	return cacheResult;
	}

	LOG.debug("Generating RelativePath SAS Key for relativePath {} inside Container {} inside Storage Account {}",
	relativePath, container, storageAccount);

	URIBuilder uriBuilder = new URIBuilder();
	uriBuilder.setPath("/" + BLOB_SAS_OP);
	uriBuilder.addParameter(STORAGE_ACCOUNT_QUERY_PARAM_NAME, storageAccount);
	uriBuilder.addParameter(CONTAINER_QUERY_PARAM_NAME, container);
	uriBuilder.addParameter(RELATIVE_PATH_QUERY_PARAM_NAME, relativePath);
	uriBuilder.addParameter(SAS_EXPIRY_QUERY_PARAM_NAME,
	"" + getSasKeyExpiryPeriod());

	RemoteSASKeyGenerationResponse sasKeyResponse =
	makeRemoteRequest(commaSeparatedUrls, uriBuilder.getPath(),
	uriBuilder.getQueryParams());
	if (sasKeyResponse.getResponseCode() == REMOTE_CALL_SUCCESS_CODE) {
	URI sasKey = new URI(sasKeyResponse.getSasKey());
	cache.put(cacheKey, sasKey);
	return sasKey;
	} else {
	throw new SASKeyGenerationException(
	"Remote Service encountered error in SAS Key generation : "
	+ sasKeyResponse.getResponseMessage());
	}
	} catch (URISyntaxException uriSyntaxEx) {
	throw new SASKeyGenerationException("Encountered URISyntaxException"
	+ " while building the HttpGetRequest to " + " remote service",
	uriSyntaxEx);
	}
	}

	/**
	* Helper method to make a remote request.
	*
	* @param urls - Urls to use for the remote request
	* @param path - hadoop.auth token for the remote request
	* @param queryParams - queryParams to be used.
	* @return RemoteSASKeyGenerationResponse
	*/
	private RemoteSASKeyGenerationResponse makeRemoteRequest(String[] urls,
	String path, List<NameValuePair> queryParams)
	throws SASKeyGenerationException {

	try {
	String responseBody = remoteCallHelper
	.makeRemoteRequest(urls, path, queryParams, HttpGet.METHOD_NAME);
	return RESPONSE_READER.readValue(responseBody);

	} catch (WasbRemoteCallException remoteCallEx) {
	throw new SASKeyGenerationException("Encountered RemoteCallException"
	+ " while retrieving SAS key from remote service", remoteCallEx);
	} catch (JsonParseException jsonParserEx) {
	throw new SASKeyGenerationException("Encountered JsonParseException "
	+ "while parsing the response from remote"
	+ " service into RemoteSASKeyGenerationResponse object",
	jsonParserEx);
	} catch (JsonMappingException jsonMappingEx) {
	throw new SASKeyGenerationException("Encountered JsonMappingException"
	+ " while mapping the response from remote service into "
	+ "RemoteSASKeyGenerationResponse object", jsonMappingEx);
	} catch (IOException ioEx) {
	throw new SASKeyGenerationException("Encountered IOException while "
	+ "accessing remote service to retrieve SAS Key", ioEx);
	}
	}
	}

	/**
	* POJO representing the response expected from a Remote
	* SAS Key generation service.
	* The remote SAS Key generation service is expected to
	* return SAS key in json format:
	* {
	* "responseCode" : 0 or non-zero <int>,
	* "responseMessage" : relavant message on failure <String>,
	* "sasKey" : Requested SAS Key <String>
	* }
	*/
	class RemoteSASKeyGenerationResponse {

	/**
	* Response code for the call.
	*/
	private int responseCode;

	/**
	* An intelligent message corresponding to
	* result. Specifically in case of failure
	* the reason for failure.
	*/
	private String responseMessage;

	/**
	* SAS Key corresponding to the request.
	*/
	private String sasKey;

	public int getResponseCode() {
	return responseCode;
	}

	public void setResponseCode(int responseCode) {
	this.responseCode = responseCode;
	}

	public String getResponseMessage() {
	return responseMessage;
	}

	public void setResponseMessage(String responseMessage) {
	this.responseMessage = responseMessage;
	}

	public String getSasKey() {
	return sasKey;
	}

	public void setSasKey(String sasKey) {
	this.sasKey = sasKey;
	}
	}