001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.lib.servlet;
020
021import com.google.common.annotations.VisibleForTesting;
022import org.apache.hadoop.classification.InterfaceAudience;
023import org.apache.hadoop.conf.Configuration;
024import org.apache.hadoop.lib.server.Server;
025import org.apache.hadoop.lib.server.ServerException;
026
027import javax.servlet.ServletContextEvent;
028import javax.servlet.ServletContextListener;
029import java.net.InetAddress;
030import java.net.InetSocketAddress;
031import java.net.UnknownHostException;
032import java.text.MessageFormat;
033
034/**
035 * {@link Server} subclass that implements <code>ServletContextListener</code>
036 * and uses its lifecycle to start and stop the server.
037 */
038@InterfaceAudience.Private
039public abstract class ServerWebApp extends Server implements ServletContextListener {
040
041  private static final String HOME_DIR = ".home.dir";
042  private static final String CONFIG_DIR = ".config.dir";
043  private static final String LOG_DIR = ".log.dir";
044  private static final String TEMP_DIR = ".temp.dir";
045  private static final String HTTP_HOSTNAME = ".http.hostname";
046  private static final String HTTP_PORT = ".http.port";
047  public static final String SSL_ENABLED = ".ssl.enabled";
048
049  private static ThreadLocal<String> HOME_DIR_TL = new ThreadLocal<String>();
050
051  private InetSocketAddress authority;
052
053  /**
054   * Method for testing purposes.
055   */
056  public static void setHomeDirForCurrentThread(String homeDir) {
057    HOME_DIR_TL.set(homeDir);
058  }
059
060  /**
061   * Constructor for testing purposes.
062   */
063  protected ServerWebApp(String name, String homeDir, String configDir, String logDir, String tempDir,
064                         Configuration config) {
065    super(name, homeDir, configDir, logDir, tempDir, config);
066  }
067
068  /**
069   * Constructor for testing purposes.
070   */
071  protected ServerWebApp(String name, String homeDir, Configuration config) {
072    super(name, homeDir, config);
073  }
074
075  /**
076   * Constructor. Subclasses must have a default constructor specifying
077   * the server name.
078   * <p/>
079   * The server name is used to resolve the Java System properties that define
080   * the server home, config, log and temp directories.
081   * <p/>
082   * The home directory is looked in the Java System property
083   * <code>#SERVER_NAME#.home.dir</code>.
084   * <p/>
085   * The config directory is looked in the Java System property
086   * <code>#SERVER_NAME#.config.dir</code>, if not defined it resolves to
087   * the <code>#SERVER_HOME_DIR#/conf</code> directory.
088   * <p/>
089   * The log directory is looked in the Java System property
090   * <code>#SERVER_NAME#.log.dir</code>, if not defined it resolves to
091   * the <code>#SERVER_HOME_DIR#/log</code> directory.
092   * <p/>
093   * The temp directory is looked in the Java System property
094   * <code>#SERVER_NAME#.temp.dir</code>, if not defined it resolves to
095   * the <code>#SERVER_HOME_DIR#/temp</code> directory.
096   *
097   * @param name server name.
098   */
099  public ServerWebApp(String name) {
100    super(name, getHomeDir(name),
101          getDir(name, CONFIG_DIR, getHomeDir(name) + "/conf"),
102          getDir(name, LOG_DIR, getHomeDir(name) + "/log"),
103          getDir(name, TEMP_DIR, getHomeDir(name) + "/temp"), null);
104  }
105
106  /**
107   * Returns the server home directory.
108   * <p/>
109   * It is looked up in the Java System property
110   * <code>#SERVER_NAME#.home.dir</code>.
111   *
112   * @param name the server home directory.
113   *
114   * @return the server home directory.
115   */
116  static String getHomeDir(String name) {
117    String homeDir = HOME_DIR_TL.get();
118    if (homeDir == null) {
119      String sysProp = name + HOME_DIR;
120      homeDir = System.getProperty(sysProp);
121      if (homeDir == null) {
122        throw new IllegalArgumentException(MessageFormat.format("System property [{0}] not defined", sysProp));
123      }
124    }
125    return homeDir;
126  }
127
128  /**
129   * Convenience method that looks for Java System property defining a
130   * diretory and if not present defaults to the specified directory.
131   *
132   * @param name server name, used as prefix of the Java System property.
133   * @param dirType dir type, use as postfix of the Java System property.
134   * @param defaultDir the default directory to return if the Java System
135   * property <code>name + dirType</code> is not defined.
136   *
137   * @return the directory defined in the Java System property or the
138   *         the default directory if the Java System property is not defined.
139   */
140  static String getDir(String name, String dirType, String defaultDir) {
141    String sysProp = name + dirType;
142    return System.getProperty(sysProp, defaultDir);
143  }
144
145  /**
146   * Initializes the <code>ServletContextListener</code> which initializes
147   * the Server.
148   *
149   * @param event servelt context event.
150   */
151  @Override
152  public void contextInitialized(ServletContextEvent event) {
153    try {
154      init();
155    } catch (ServerException ex) {
156      event.getServletContext().log("ERROR: " + ex.getMessage());
157      throw new RuntimeException(ex);
158    }
159  }
160
161  /**
162   * Resolves the host & port InetSocketAddress the web server is listening to.
163   * <p/>
164   * This implementation looks for the following 2 properties:
165   * <ul>
166   *   <li>#SERVER_NAME#.http.hostname</li>
167   *   <li>#SERVER_NAME#.http.port</li>
168   * </ul>
169   *
170   * @return the host & port InetSocketAddress the web server is listening to.
171   * @throws ServerException thrown if any of the above 2 properties is not defined.
172   */
173  protected InetSocketAddress resolveAuthority() throws ServerException {
174    String hostnameKey = getName() + HTTP_HOSTNAME;
175    String portKey = getName() + HTTP_PORT;
176    String host = System.getProperty(hostnameKey);
177    String port = System.getProperty(portKey);
178    if (host == null) {
179      throw new ServerException(ServerException.ERROR.S13, hostnameKey);
180    }
181    if (port == null) {
182      throw new ServerException(ServerException.ERROR.S13, portKey);
183    }
184    try {
185      InetAddress add = InetAddress.getByName(host);
186      int portNum = Integer.parseInt(port);
187      return new InetSocketAddress(add, portNum);
188    } catch (UnknownHostException ex) {
189      throw new ServerException(ServerException.ERROR.S14, ex.toString(), ex);
190    }
191  }
192
193  /**
194   * Destroys the <code>ServletContextListener</code> which destroys
195   * the Server.
196   *
197   * @param event servelt context event.
198   */
199  @Override
200  public void contextDestroyed(ServletContextEvent event) {
201    destroy();
202  }
203
204  /**
205   * Returns the hostname:port InetSocketAddress the webserver is listening to.
206   *
207   * @return the hostname:port InetSocketAddress the webserver is listening to.
208   */
209  public InetSocketAddress getAuthority() throws ServerException {
210    synchronized (this) {
211      if (authority == null) {
212          authority = resolveAuthority();
213      }
214    }
215    return authority;
216  }
217
218  /**
219   * Sets an alternate hostname:port InetSocketAddress to use.
220   * <p/>
221   * For testing purposes.
222   * 
223   * @param authority alterante authority.
224   */
225  @VisibleForTesting
226  public void setAuthority(InetSocketAddress authority) {
227    this.authority = authority;
228  }
229
230
231  /**
232   *
233   */
234  public boolean isSslEnabled() {
235    return Boolean.valueOf(System.getProperty(getName() + SSL_ENABLED, "false"));
236  }
237}