hdfs/src/java/org/apache/hadoop/hdfs/tools/GetConf.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.hdfs.tools;

 import java.io.IOException;
 import java.io.PrintStream;
 import java.net.InetSocketAddress;
 import java.security.PrivilegedExceptionAction;
 import java.util.List;

 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;

 /**
  * Tool for getting configuration information from a configuration file.
  *
  * Adding more options:
  * <ul>
  * <li>
  * If adding a simple option to get a value corresponding to a key in the
  * configuration, use regular {@link GetConf.CommandHandler}.
  * See {@link GetConf.Command#EXCLUDE_FILE} example.
  * </li>
  * <li>
  * If adding an option that is does not return a value for a key, add
  * a subclass of {@link GetConf.CommandHandler} and set it up in
  * {@link GetConf.Command}.
  *
  * See {@link GetConf.Command#NAMENODE} for example.
  * </ul>
  */
 public class GetConf extends Configured implements Tool {
   private static final String DESCRIPTION = "hdfs getconf is utility for "
       + "getting configuration information from the config file.\n";

   enum Command {
     NAMENODE("-namenodes", new NameNodesCommandHandler(),
         "gets list of namenodes in the cluster."),
     SECONDARY("-secondaryNameNodes", new SecondaryNameNodesCommandHandler(),
         "gets list of secondary namenodes in the cluster."),
     BACKUP("-backupNodes", new BackupNodesCommandHandler(),
         "gets list of backup nodes in the cluster."),
     INCLUDE_FILE("-includeFile",
         new CommandHandler("DFSConfigKeys.DFS_HOSTS"),
         "gets the include file path that defines the datanodes " +
         "that can join the cluster."),
     EXCLUDE_FILE("-excludeFile",
         new CommandHandler("DFSConfigKeys.DFS_HOSTS_EXCLUDE"),
         "gets the exclude file path that defines the datanodes " +
         "that need to decommissioned."),
     NNRPCADDRESSES("-nnRpcAddresses",
     		new NNRpcAddressesCommandHandler(),
         "gets the namenode rpc addresses");

     private final String cmd;
     private final CommandHandler handler;
     private final String description;

     Command(String cmd, CommandHandler handler, String description) {
       this.cmd = cmd;
       this.handler = handler;
       this.description = description;
     }

     public String getName() {
       return cmd;
     }

     public String getDescription() {
       return description;
     }

     public static CommandHandler getHandler(String name) {
       for (Command cmd : values()) {
         if (cmd.getName().equalsIgnoreCase(name)) {
           return cmd.handler;
         }
       }
       return null;
     }
   }

   static final String USAGE;
   static {
     Configuration.addDefaultResource("hdfs-default.xml");
     Configuration.addDefaultResource("hdfs-site.xml");

     /* Initialize USAGE based on Command values */
     StringBuilder usage = new StringBuilder(DESCRIPTION);
     usage.append("\nhadoop getconf \n");
     for (Command cmd : Command.values()) {
       usage.append("\t[" + cmd.getName() + "]\t\t\t" + cmd.getDescription()
           + "\n");
     }
     USAGE = usage.toString();
   }

   /**
    * Handler to return value for key corresponding to the {@link Command}
    */
   static class CommandHandler {
     final String key; // Configuration key to lookup

     CommandHandler() {
       this(null);
     }

     CommandHandler(String key) {
       this.key = key;
     }

     final int doWork(GetConf tool) {
       try {
         return doWorkInternal(tool);
       } catch (Exception e) {
         tool.printError(e.getMessage());
       }
       return -1;
     }

     /** Method to be overridden by sub classes for specific behavior */
     int doWorkInternal(GetConf tool) throws Exception {
       String value = tool.getConf().get(key);
       if (value != null) {
         tool.printOut(value);
         return 0;
       }
       tool.printError("Configuration " + key + " is missing.");
       return -1;
     }
   }

   /**
    * Handler for {@link Command#NAMENODE}
    */
   static class NameNodesCommandHandler extends CommandHandler {
     @Override
     int doWorkInternal(GetConf tool) throws IOException {
       tool.printList(DFSUtil.getNNServiceRpcAddresses(tool.getConf()));
       return 0;
     }
   }

   /**
    * Handler for {@link Command#BACKUP}
    */
   static class BackupNodesCommandHandler extends CommandHandler {
     @Override
     public int doWorkInternal(GetConf tool) throws IOException {
       tool.printList(DFSUtil.getBackupNodeAddresses(tool.getConf()));
       return 0;
     }
   }

   /**
    * Handler for {@link Command#SECONDARY}
    */
   static class SecondaryNameNodesCommandHandler extends CommandHandler {
     @Override
     public int doWorkInternal(GetConf tool) throws IOException {
       tool.printList(DFSUtil.getSecondaryNameNodeAddresses(tool.getConf()));
       return 0;
     }
   }

   /**
    * Handler for {@link Command#NNRPCADDRESSES}
    * If rpc addresses are defined in configuration, we return them. Otherwise,
    * return empty string.
    */
   static class NNRpcAddressesCommandHandler extends CommandHandler {
     @Override
     public int doWorkInternal(GetConf tool) throws IOException {
       Configuration config = tool.getConf();
       List<InetSocketAddress> rpclist = DFSUtil.getNNServiceRpcAddresses(config);
       if (rpclist != null) {
         for (InetSocketAddress rpc : rpclist) {
           tool.printOut(rpc.getHostName()+":"+rpc.getPort());
         }
         return 0;
       }
       tool.printError("Did not get namenode service rpc addresses.");
       return -1;
     }
   }

   private final PrintStream out; // Stream for printing command output
   private final PrintStream err; // Stream for printing error

   GetConf(Configuration conf) {
     this(conf, System.out, System.err);
   }

   GetConf(Configuration conf, PrintStream out, PrintStream err) {
     super(conf);
     this.out = out;
     this.err = err;
   }

   void printError(String message) {
     err.println(message);
   }

   void printOut(String message) {
     out.println(message);
   }

   void printList(List<InetSocketAddress> list) {
     StringBuilder buffer = new StringBuilder();
     for (InetSocketAddress address : list) {
       buffer.append(address.getHostName()).append(" ");
     }
     printOut(buffer.toString());
   }

   private void printUsage() {
     printError(USAGE);
   }

   /**
    * Main method that runs the tool for given arguments.
    * @param args arguments
    * @return return status of the command
    */
   private int doWork(String[] args) {
     if (args.length == 1) {
       CommandHandler handler = Command.getHandler(args[0]);
       if (handler != null) {
         return handler.doWork(this);
       }
     }
     printUsage();
     return -1;
   }

   @Override
   public int run(final String[] args) throws Exception {
     try {
       return UserGroupInformation.getCurrentUser().doAs(
           new PrivilegedExceptionAction<Integer>() {
             @Override
             public Integer run() throws Exception {
               return doWork(args);
             }
           });
     } catch (InterruptedException e) {
       throw new IOException(e);
     }
   }

   public static void main(String[] args) throws Exception {
     int res = ToolRunner.run(new GetConf(new HdfsConfiguration()), args);
     System.exit(res);
   }
 }
	/**
	* 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.IOException;
	import java.io.PrintStream;
	import java.net.InetSocketAddress;
	import java.security.PrivilegedExceptionAction;
	import java.util.List;

	import org.apache.hadoop.conf.Configuration;
	import org.apache.hadoop.conf.Configured;
	import org.apache.hadoop.hdfs.DFSUtil;
	import org.apache.hadoop.hdfs.HdfsConfiguration;
	import org.apache.hadoop.security.UserGroupInformation;
	import org.apache.hadoop.util.Tool;
	import org.apache.hadoop.util.ToolRunner;

	/**
	* Tool for getting configuration information from a configuration file.
	*
	* Adding more options:
	* <ul>
	* <li>
	* If adding a simple option to get a value corresponding to a key in the
	* configuration, use regular {@link GetConf.CommandHandler}.
	* See {@link GetConf.Command#EXCLUDE_FILE} example.
	* </li>
	* <li>
	* If adding an option that is does not return a value for a key, add
	* a subclass of {@link GetConf.CommandHandler} and set it up in
	* {@link GetConf.Command}.
	*
	* See {@link GetConf.Command#NAMENODE} for example.
	* </ul>
	*/
	public class GetConf extends Configured implements Tool {
	private static final String DESCRIPTION = "hdfs getconf is utility for "
	+ "getting configuration information from the config file.\n";

	enum Command {
	NAMENODE("-namenodes", new NameNodesCommandHandler(),
	"gets list of namenodes in the cluster."),
	SECONDARY("-secondaryNameNodes", new SecondaryNameNodesCommandHandler(),
	"gets list of secondary namenodes in the cluster."),
	BACKUP("-backupNodes", new BackupNodesCommandHandler(),
	"gets list of backup nodes in the cluster."),
	INCLUDE_FILE("-includeFile",
	new CommandHandler("DFSConfigKeys.DFS_HOSTS"),
	"gets the include file path that defines the datanodes " +
	"that can join the cluster."),
	EXCLUDE_FILE("-excludeFile",
	new CommandHandler("DFSConfigKeys.DFS_HOSTS_EXCLUDE"),
	"gets the exclude file path that defines the datanodes " +
	"that need to decommissioned."),
	NNRPCADDRESSES("-nnRpcAddresses",
	new NNRpcAddressesCommandHandler(),
	"gets the namenode rpc addresses");

	private final String cmd;
	private final CommandHandler handler;
	private final String description;

	Command(String cmd, CommandHandler handler, String description) {
	this.cmd = cmd;
	this.handler = handler;
	this.description = description;
	}

	public String getName() {
	return cmd;
	}

	public String getDescription() {
	return description;
	}

	public static CommandHandler getHandler(String name) {
	for (Command cmd : values()) {
	if (cmd.getName().equalsIgnoreCase(name)) {
	return cmd.handler;
	}
	}
	return null;
	}
	}

	static final String USAGE;
	static {
	Configuration.addDefaultResource("hdfs-default.xml");
	Configuration.addDefaultResource("hdfs-site.xml");

	/* Initialize USAGE based on Command values */
	StringBuilder usage = new StringBuilder(DESCRIPTION);
	usage.append("\nhadoop getconf \n");
	for (Command cmd : Command.values()) {
	usage.append("\t[" + cmd.getName() + "]\t\t\t" + cmd.getDescription()
	+ "\n");
	}
	USAGE = usage.toString();
	}

	/**
	* Handler to return value for key corresponding to the {@link Command}
	*/
	static class CommandHandler {
	final String key; // Configuration key to lookup

	CommandHandler() {
	this(null);
	}

	CommandHandler(String key) {
	this.key = key;
	}

	final int doWork(GetConf tool) {
	try {
	return doWorkInternal(tool);
	} catch (Exception e) {
	tool.printError(e.getMessage());
	}
	return -1;
	}

	/** Method to be overridden by sub classes for specific behavior */
	int doWorkInternal(GetConf tool) throws Exception {
	String value = tool.getConf().get(key);
	if (value != null) {
	tool.printOut(value);
	return 0;
	}
	tool.printError("Configuration " + key + " is missing.");
	return -1;
	}
	}

	/**
	* Handler for {@link Command#NAMENODE}
	*/
	static class NameNodesCommandHandler extends CommandHandler {
	@Override
	int doWorkInternal(GetConf tool) throws IOException {
	tool.printList(DFSUtil.getNNServiceRpcAddresses(tool.getConf()));
	return 0;
	}
	}

	/**
	* Handler for {@link Command#BACKUP}
	*/
	static class BackupNodesCommandHandler extends CommandHandler {
	@Override
	public int doWorkInternal(GetConf tool) throws IOException {
	tool.printList(DFSUtil.getBackupNodeAddresses(tool.getConf()));
	return 0;
	}
	}

	/**
	* Handler for {@link Command#SECONDARY}
	*/
	static class SecondaryNameNodesCommandHandler extends CommandHandler {
	@Override
	public int doWorkInternal(GetConf tool) throws IOException {
	tool.printList(DFSUtil.getSecondaryNameNodeAddresses(tool.getConf()));
	return 0;
	}
	}

	/**
	* Handler for {@link Command#NNRPCADDRESSES}
	* If rpc addresses are defined in configuration, we return them. Otherwise,
	* return empty string.
	*/
	static class NNRpcAddressesCommandHandler extends CommandHandler {
	@Override
	public int doWorkInternal(GetConf tool) throws IOException {
	Configuration config = tool.getConf();
	List<InetSocketAddress> rpclist = DFSUtil.getNNServiceRpcAddresses(config);
	if (rpclist != null) {
	for (InetSocketAddress rpc : rpclist) {
	tool.printOut(rpc.getHostName()+":"+rpc.getPort());
	}
	return 0;
	}
	tool.printError("Did not get namenode service rpc addresses.");
	return -1;
	}
	}

	private final PrintStream out; // Stream for printing command output
	private final PrintStream err; // Stream for printing error

	GetConf(Configuration conf) {
	this(conf, System.out, System.err);
	}

	GetConf(Configuration conf, PrintStream out, PrintStream err) {
	super(conf);
	this.out = out;
	this.err = err;
	}

	void printError(String message) {
	err.println(message);
	}

	void printOut(String message) {
	out.println(message);
	}

	void printList(List<InetSocketAddress> list) {
	StringBuilder buffer = new StringBuilder();
	for (InetSocketAddress address : list) {
	buffer.append(address.getHostName()).append(" ");
	}
	printOut(buffer.toString());
	}

	private void printUsage() {
	printError(USAGE);
	}

	/**
	* Main method that runs the tool for given arguments.
	* @param args arguments
	* @return return status of the command
	*/
	private int doWork(String[] args) {
	if (args.length == 1) {
	CommandHandler handler = Command.getHandler(args[0]);
	if (handler != null) {
	return handler.doWork(this);
	}
	}
	printUsage();
	return -1;
	}

	@Override
	public int run(final String[] args) throws Exception {
	try {
	return UserGroupInformation.getCurrentUser().doAs(
	new PrivilegedExceptionAction<Integer>() {
	@Override
	public Integer run() throws Exception {
	return doWork(args);
	}
	});
	} catch (InterruptedException e) {
	throw new IOException(e);
	}
	}

	public static void main(String[] args) throws Exception {
	int res = ToolRunner.run(new GetConf(new HdfsConfiguration()), args);
	System.exit(res);
	}
	}