org.apache.hadoop.hdfs.HdfsDtFetcher Maven / Gradle / Ivy
/**
* 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.hdfs;
import java.io.IOException;
import java.net.URI;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.DtFetcher;
import org.apache.hadoop.security.token.Token;
/**
* DtFetcher is an interface which permits the abstraction and separation of
* delegation token fetch implementaions across different packages and
* compilation units. Resolution of fetcher impl will be done at runtime.
*/
public class HdfsDtFetcher implements DtFetcher {
private static final Logger LOG =
LoggerFactory.getLogger(HdfsDtFetcher.class);
private static final String SERVICE_NAME = HdfsConstants.HDFS_URI_SCHEME;
private static final String FETCH_FAILED = "Fetch of delegation token failed";
/**
* Returns the service name for HDFS, which is also a valid URL prefix.
*/
public Text getServiceName() {
return new Text(SERVICE_NAME);
}
public boolean isTokenRequired() {
return UserGroupInformation.isSecurityEnabled();
}
/**
* Returns Token object via FileSystem, null if bad argument.
* @param conf - a Configuration object used with FileSystem.get()
* @param creds - a Credentials object to which token(s) will be added
* @param renewer - the renewer to send with the token request
* @param url - the URL to which the request is sent
* @return a Token, or null if fetch fails.
*/
public Token addDelegationTokens(Configuration conf, Credentials creds,
String renewer, String url) throws Exception {
if (!url.startsWith(getServiceName().toString())) {
url = getServiceName().toString() + "://" + url;
}
FileSystem fs = FileSystem.get(URI.create(url), conf);
Token token = fs.getDelegationToken(renewer);
if (token == null) {
LOG.error(FETCH_FAILED);
throw new IOException(FETCH_FAILED);
}
creds.addToken(token.getService(), token);
return token;
}
}