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1   /**
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing, software
13   * distributed under the License is distributed on an "AS IS" BASIS,
14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   * See the License for the specific language governing permissions and
16   * limitations under the License.
17   */
18  
19  package org.apache.hadoop.hbase.rest;
20  
21  import java.io.IOException;
22  
23  import org.apache.hadoop.hbase.classification.InterfaceAudience;
24  import org.apache.hadoop.conf.Configuration;
25  import org.apache.hadoop.hbase.client.HBaseAdmin;
26  import org.apache.hadoop.hbase.client.Table;
27  import org.apache.hadoop.hbase.filter.ParseFilter;
28  import org.apache.hadoop.hbase.security.UserProvider;
29  import org.apache.hadoop.hbase.util.ConnectionCache;
30  import org.apache.hadoop.security.UserGroupInformation;
31  import org.apache.hadoop.security.authorize.ProxyUsers;
32  import org.apache.log4j.Logger;
33  
34  /**
35   * Singleton class encapsulating global REST servlet state and functions.
36   */
37  @InterfaceAudience.Private
38  public class RESTServlet implements Constants {
39    private static Logger LOG = Logger.getLogger(RESTServlet.class);
40    private static RESTServlet INSTANCE;
41    private final Configuration conf;
42    private final MetricsREST metrics = new MetricsREST();
43    private final ConnectionCache connectionCache;
44    private final UserGroupInformation realUser;
45  
46    static final String CLEANUP_INTERVAL = "hbase.rest.connection.cleanup-interval";
47    static final String MAX_IDLETIME = "hbase.rest.connection.max-idletime";
48    static final String HBASE_REST_SUPPORT_PROXYUSER = "hbase.rest.support.proxyuser";
49  
50    UserGroupInformation getRealUser() {
51      return realUser;
52    }
53  
54    /**
55     * @return the RESTServlet singleton instance
56     */
57    public synchronized static RESTServlet getInstance() {
58      assert(INSTANCE != null);
59      return INSTANCE;
60    }
61  
62    /**
63     * @param conf Existing configuration to use in rest servlet
64     * @param userProvider the login user provider
65     * @return the RESTServlet singleton instance
66     * @throws IOException
67     */
68    public synchronized static RESTServlet getInstance(Configuration conf,
69        UserProvider userProvider) throws IOException {
70      if (INSTANCE == null) {
71        INSTANCE = new RESTServlet(conf, userProvider);
72      }
73      return INSTANCE;
74    }
75  
76    public synchronized static void stop() {
77      if (INSTANCE != null)  INSTANCE = null;
78    }
79  
80    /**
81     * Constructor with existing configuration
82     * @param conf existing configuration
83     * @param userProvider the login user provider
84     * @throws IOException
85     */
86    RESTServlet(final Configuration conf,
87        final UserProvider userProvider) throws IOException {
88      this.realUser = userProvider.getCurrent().getUGI();
89      this.conf = conf;
90      registerCustomFilter(conf);
91  
92      int cleanInterval = conf.getInt(CLEANUP_INTERVAL, 10 * 1000);
93      int maxIdleTime = conf.getInt(MAX_IDLETIME, 10 * 60 * 1000);
94      connectionCache = new ConnectionCache(
95        conf, userProvider, cleanInterval, maxIdleTime);
96      if (supportsProxyuser()) {
97        ProxyUsers.refreshSuperUserGroupsConfiguration(conf);
98      }
99    }
100 
101   HBaseAdmin getAdmin() throws IOException {
102     return connectionCache.getAdmin();
103   }
104 
105   /**
106    * Caller closes the table afterwards.
107    */
108   Table getTable(String tableName) throws IOException {
109     return connectionCache.getTable(tableName);
110   }
111 
112   Configuration getConfiguration() {
113     return conf;
114   }
115 
116   MetricsREST getMetrics() {
117     return metrics;
118   }
119 
120   /**
121    * Helper method to determine if server should
122    * only respond to GET HTTP method requests.
123    * @return boolean for server read-only state
124    */
125   boolean isReadOnly() {
126     return getConfiguration().getBoolean("hbase.rest.readonly", false);
127   }
128 
129   void setEffectiveUser(String effectiveUser) {
130     connectionCache.setEffectiveUser(effectiveUser);
131   }
132 
133   boolean supportsProxyuser() {
134     return conf.getBoolean(HBASE_REST_SUPPORT_PROXYUSER, false);
135   }
136 
137   private void registerCustomFilter(Configuration conf) {
138     String[] filterList = conf.getStrings(Constants.CUSTOM_FILTERS);
139     if (filterList != null) {
140       for (String filterClass : filterList) {
141         String[] filterPart = filterClass.split(":");
142         if (filterPart.length != 2) {
143           LOG.warn(
144             "Invalid filter specification " + filterClass + " - skipping");
145         } else {
146           ParseFilter.registerFilter(filterPart[0], filterPart[1]);
147         }
148       }
149     }
150   }
151 }