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
019 package org.apache.hadoop.fs.http.server;
020
021 import org.apache.hadoop.classification.InterfaceAudience;
022 import org.apache.hadoop.conf.Configuration;
023 import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
024 import org.apache.hadoop.lib.server.ServerException;
025 import org.apache.hadoop.lib.service.FileSystemAccess;
026 import org.apache.hadoop.lib.servlet.ServerWebApp;
027 import org.apache.hadoop.lib.wsrs.UserProvider;
028 import org.slf4j.Logger;
029 import org.slf4j.LoggerFactory;
030
031 import java.io.IOException;
032
033 /**
034 * Bootstrap class that manages the initialization and destruction of the
035 * HttpFSServer server, it is a <code>javax.servlet.ServletContextListener
036 * </code> implementation that is wired in HttpFSServer's WAR
037 * <code>WEB-INF/web.xml</code>.
038 * <p/>
039 * It provides acces to the server context via the singleton {@link #get}.
040 * <p/>
041 * All the configuration is loaded from configuration properties prefixed
042 * with <code>httpfs.</code>.
043 */
044 @InterfaceAudience.Private
045 public class HttpFSServerWebApp extends ServerWebApp {
046 private static final Logger LOG =
047 LoggerFactory.getLogger(HttpFSServerWebApp.class);
048
049 /**
050 * Server name and prefix for all configuration properties.
051 */
052 public static final String NAME = "httpfs";
053
054 /**
055 * Configuration property that defines HttpFSServer admin group.
056 */
057 public static final String CONF_ADMIN_GROUP = "admin.group";
058
059 private static HttpFSServerWebApp SERVER;
060
061 private String adminGroup;
062
063 /**
064 * Default constructor.
065 *
066 * @throws IOException thrown if the home/conf/log/temp directory paths
067 * could not be resolved.
068 */
069 public HttpFSServerWebApp() throws IOException {
070 super(NAME);
071 }
072
073 /**
074 * Constructor used for testing purposes.
075 */
076 public HttpFSServerWebApp(String homeDir, String configDir, String logDir,
077 String tempDir, Configuration config) {
078 super(NAME, homeDir, configDir, logDir, tempDir, config);
079 }
080
081 /**
082 * Constructor used for testing purposes.
083 */
084 public HttpFSServerWebApp(String homeDir, Configuration config) {
085 super(NAME, homeDir, config);
086 }
087
088 /**
089 * Initializes the HttpFSServer server, loads configuration and required
090 * services.
091 *
092 * @throws ServerException thrown if HttpFSServer server could not be
093 * initialized.
094 */
095 @Override
096 public void init() throws ServerException {
097 if (SERVER != null) {
098 throw new RuntimeException("HttpFSServer server already initialized");
099 }
100 SERVER = this;
101 super.init();
102 adminGroup = getConfig().get(getPrefixedName(CONF_ADMIN_GROUP), "admin");
103 LOG.info("Connects to Namenode [{}]",
104 get().get(FileSystemAccess.class).getFileSystemConfiguration().
105 get(CommonConfigurationKeysPublic.FS_DEFAULT_NAME_KEY));
106 String userPattern = getConfig().get(UserProvider.USER_PATTERN_KEY,
107 UserProvider.USER_PATTERN_DEFAULT);
108 UserProvider.setUserPattern(userPattern);
109 }
110
111 /**
112 * Shutdowns all running services.
113 */
114 @Override
115 public void destroy() {
116 SERVER = null;
117 super.destroy();
118 }
119
120 /**
121 * Returns HttpFSServer server singleton, configuration and services are
122 * accessible through it.
123 *
124 * @return the HttpFSServer server singleton.
125 */
126 public static HttpFSServerWebApp get() {
127 return SERVER;
128 }
129
130 /**
131 * Returns HttpFSServer admin group.
132 *
133 * @return httpfs admin group.
134 */
135 public String getAdminGroup() {
136 return adminGroup;
137 }
138
139 }