org.apache.hadoop.hdfs.server.datanode.SecureDataNodeStarter.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.datanode.SecureDataNodeStarter.java

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/**
 * 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.server.datanode;

import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_SECURITY_AUTHENTICATION;

import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.channels.ServerSocketChannel;

import org.apache.commons.daemon.Daemon;
import org.apache.commons.daemon.DaemonContext;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.server.common.HdfsConstants;
import org.apache.hadoop.http.HttpServer;
import org.mortbay.jetty.nio.SelectChannelConnector;

/**
 * Utility class to start a datanode in a secure cluster, first obtaining 
 * privileged resources before main startup and handing them to the datanode.
 */
public class SecureDataNodeStarter implements Daemon {
    /**
     * Stash necessary resources needed for datanode operation in a secure env.
     */
    public static class SecureResources {
        private final ServerSocket streamingSocket;
        private final SelectChannelConnector listener;

        public SecureResources(ServerSocket streamingSocket, SelectChannelConnector listener) {

            this.streamingSocket = streamingSocket;
            this.listener = listener;
        }

        public ServerSocket getStreamingSocket() {
            return streamingSocket;
        }

        public SelectChannelConnector getListener() {
            return listener;
        }
    }

    private String[] args;
    private SecureResources resources;

    @Override
    public void init(DaemonContext context) throws Exception {
        System.err.println("Initializing secure datanode resources");
        // We should only start up a secure datanode in a Kerberos-secured cluster
        Configuration conf = new Configuration(); // Skip UGI method to not log in
        if (!conf.get(HADOOP_SECURITY_AUTHENTICATION).equals("kerberos"))
            throw new RuntimeException("Cannot start secure datanode in unsecure cluster");

        // Stash command-line arguments for regular datanode
        args = context.getArguments();

        // Obtain secure port for data streaming to datanode
        InetSocketAddress socAddr = DataNode.getStreamingAddr(conf);
        int socketWriteTimeout = conf.getInt("dfs.datanode.socket.write.timeout", HdfsConstants.WRITE_TIMEOUT);

        ServerSocket ss = (socketWriteTimeout > 0) ? ServerSocketChannel.open().socket() : new ServerSocket();
        ss.bind(socAddr, 0);

        // Check that we got the port we need
        if (ss.getLocalPort() != socAddr.getPort())
            throw new RuntimeException("Unable to bind on specified streaming port in secure " + "context. Needed "
                    + socAddr.getPort() + ", got " + ss.getLocalPort());

        // Obtain secure listener for web server
        SelectChannelConnector listener = (SelectChannelConnector) HttpServer.createDefaultChannelConnector();
        InetSocketAddress infoSocAddr = DataNode.getInfoAddr(conf);
        listener.setHost(infoSocAddr.getHostName());
        listener.setPort(infoSocAddr.getPort());
        // Open listener here in order to bind to port as root
        listener.open();
        if (listener.getPort() != infoSocAddr.getPort())
            throw new RuntimeException("Unable to bind on specified info port in secure " + "context. Needed "
                    + socAddr.getPort() + ", got " + ss.getLocalPort());

        if (ss.getLocalPort() >= 1023 || listener.getPort() >= 1023)
            throw new RuntimeException(
                    "Cannot start secure datanode on non-privileged " + " ports. (streaming port = " + ss
                            + " ) (http listener port = " + listener.getConnection() + "). Exiting.");

        System.err.println("Successfully obtained privileged resources (streaming port = " + ss
                + " ) (http listener port = " + listener.getConnection() + ")");

        resources = new SecureResources(ss, listener);
    }

    @Override
    public void start() throws Exception {
        System.err.println("Starting regular datanode initialization");
        DataNode.secureMain(args, resources);
    }

    @Override
    public void destroy() {
        /* Nothing to do */ }

    @Override
    public void stop() throws Exception {
        /* Nothing to do */ }
}