hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DelegationTokenFetcher.java

/**
 * 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.tools;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.net.URI;
import java.security.PrivilegedExceptionAction;
import java.util.Collection;
import java.util.Date;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Options;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenSecretManager;
import org.apache.hadoop.hdfs.security.token.delegation.DelegationUtilsClient;
import org.apache.hadoop.hdfs.web.URLConnectionFactory;

import org.apache.hadoop.security.Credentials;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.util.ExitUtil;
import org.apache.hadoop.util.GenericOptionsParser;

/**
 * Fetch a DelegationToken from the current Namenode and store it in the
 * specified file.
 */
@InterfaceAudience.Private
public class DelegationTokenFetcher {
  private static final Log LOG = 
    LogFactory.getLog(DelegationTokenFetcher.class);
  private static final String WEBSERVICE = "webservice";
  private static final String RENEWER = "renewer";
  private static final String CANCEL = "cancel";
  private static final String RENEW = "renew";
  private static final String PRINT = "print";
  private static final String HELP = "help";
  private static final String HELP_SHORT = "h";

  private static void printUsage(PrintStream err) {
    err.println("fetchdt retrieves delegation tokens from the NameNode");
    err.println();
    err.println("fetchdt <opts> <token file>");
    err.println("Options:");
    err.println("  --webservice <url>  Url to contact NN on");
    err.println("  --renewer <name>    Name of the delegation token renewer");
    err.println("  --cancel            Cancel the delegation token");
    err.println("  --renew             Renew the delegation token.  Delegation " 
    		+ "token must have been fetched using the --renewer <name> option.");
    err.println("  --print             Print the delegation token");
    err.println();
    GenericOptionsParser.printGenericCommandUsage(err);
    ExitUtil.terminate(1);    
  }

  private static Collection<Token<?>> readTokens(Path file, Configuration conf)
      throws IOException {
    Credentials creds = Credentials.readTokenStorageFile(file, conf);
    return creds.getAllTokens();
  }
    
  /**
   * Command-line interface
   */
  public static void main(final String[] args) throws Exception {
    final Configuration conf = new HdfsConfiguration();
    Options fetcherOptions = new Options();
    fetcherOptions.addOption(WEBSERVICE, true,
        "HTTP url to reach the NameNode at");
    fetcherOptions.addOption(RENEWER, true,
        "Name of the delegation token renewer");
    fetcherOptions.addOption(CANCEL, false, "cancel the token");
    fetcherOptions.addOption(RENEW, false, "renew the token");
    fetcherOptions.addOption(PRINT, false, "print the token");
    fetcherOptions.addOption(HELP_SHORT, HELP, false, "print out help information");
    GenericOptionsParser parser = new GenericOptionsParser(conf,
        fetcherOptions, args);
    CommandLine cmd = parser.getCommandLine();
    
    // get options
    final String webUrl = cmd.hasOption(WEBSERVICE) ? cmd
        .getOptionValue(WEBSERVICE) : null;
    final String renewer = cmd.hasOption(RENEWER) ? 
        cmd.getOptionValue(RENEWER) : null;
    final boolean cancel = cmd.hasOption(CANCEL);
    final boolean renew = cmd.hasOption(RENEW);
    final boolean print = cmd.hasOption(PRINT);
    final boolean help = cmd.hasOption(HELP);
    String[] remaining = parser.getRemainingArgs();

    // check option validity
    if (help) {
      printUsage(System.out);
      System.exit(0);
    }
    if (cancel && renew || cancel && print || renew && print || cancel && renew
        && print) {
      System.err.println("ERROR: Only specify cancel, renew or print.");
      printUsage(System.err);
    }
    if (remaining.length != 1 || remaining[0].charAt(0) == '-') {
      System.err.println("ERROR: Must specify exacltly one token file");
      printUsage(System.err);
    }
    // default to using the local file system
    FileSystem local = FileSystem.getLocal(conf);
    final Path tokenFile = new Path(local.getWorkingDirectory(), remaining[0]);
    final URLConnectionFactory connectionFactory = URLConnectionFactory.DEFAULT_SYSTEM_CONNECTION_FACTORY;

    // Login the current user
    UserGroupInformation.getCurrentUser().doAs(
        new PrivilegedExceptionAction<Object>() {
          @Override
          public Object run() throws Exception {
            if (print) {
              DelegationTokenIdentifier id = new DelegationTokenSecretManager(
                  0, 0, 0, 0, null).createIdentifier();
              for (Token<?> token : readTokens(tokenFile, conf)) {
                DataInputStream in = new DataInputStream(
                    new ByteArrayInputStream(token.getIdentifier()));
                id.readFields(in);
                System.out.println("Token (" + id + ") for " + token.getService());
              }
              return null;
            }
            
            if (renew) {
              for (Token<?> token : readTokens(tokenFile, conf)) {
                if (token.isManaged()) {
                  long result = token.renew(conf);
                  if (LOG.isDebugEnabled()) {
                    LOG.debug("Renewed token for " + token.getService()
                        + " until: " + new Date(result));
                  }
                }
              }
            } else if (cancel) {
              for(Token<?> token: readTokens(tokenFile, conf)) {
                if (token.isManaged()) {
                  token.cancel(conf);
                  if (LOG.isDebugEnabled()) {
                    LOG.debug("Cancelled token for " + token.getService());
                  }
                }
              }
            } else {
              // otherwise we are fetching
              if (webUrl != null) {
                Credentials creds = DelegationUtilsClient.getDTfromRemote(
                    connectionFactory, new URI(webUrl), renewer, null);
                creds.writeTokenStorageFile(tokenFile, conf);
                for (Token<?> token : creds.getAllTokens()) {
                  System.out.println("Fetched token via " + webUrl + " for "
                      + token.getService() + " into " + tokenFile);
                }
              } else {
                FileSystem fs = FileSystem.get(conf);
                Credentials cred = new Credentials();
                Token<?> tokens[] = fs.addDelegationTokens(renewer, cred);
                cred.writeTokenStorageFile(tokenFile, conf);
                for (Token<?> token : tokens) {
                  System.out.println("Fetched token for " + token.getService()
                      + " into " + tokenFile);
                }
              }
            }
            return null;
          }
        });
  }

}