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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  package org.apache.hadoop.hbase.client;
19  
20  import java.io.IOException;
21  
22  import org.apache.hadoop.conf.Configuration;
23  import org.apache.hadoop.hbase.BaseConfigurable;
24  import org.apache.hadoop.hbase.security.User;
25  import org.apache.hadoop.security.UserGroupInformation;
26  import org.apache.hadoop.util.ReflectionUtils;
27  
28  /**
29   * Provide an instance of a user. Allows custom {@link User} creation.
30   */
31  public class UserProvider extends BaseConfigurable {
32  
33    private static final String USER_PROVIDER_CONF_KEY = "hbase.client.userprovider.class";
34  
35    /**
36     * Instantiate the {@link UserProvider} specified in the configuration and set the passed
37     * configuration via {@link UserProvider#setConf(Configuration)}
38     * @param conf to read and set on the created {@link UserProvider}
39     * @return a {@link UserProvider} ready for use.
40     */
41    public static UserProvider instantiate(Configuration conf){
42      Class<? extends UserProvider> clazz =
43          conf.getClass(USER_PROVIDER_CONF_KEY, UserProvider.class, UserProvider.class);
44      return ReflectionUtils.newInstance(clazz, conf);
45    }
46  
47    /**
48     * Set the {@link UserProvider} in the given configuration that should be instantiated
49     * @param conf to update
50     * @param provider class of the provider to set
51     */
52    public static void setUserProviderForTesting(Configuration conf,
53        Class<? extends UserProvider> provider) {
54      conf.set(USER_PROVIDER_CONF_KEY, provider.getName());
55    }
56  
57    /**
58     * @return the userName for the current logged-in user.
59     * @throws IOException if the underlying user cannot be obtained
60     */
61    public String getCurrentUserName() throws IOException {
62      User user = getCurrent();
63      return user == null ? null : user.getName();
64    }
65  
66    /**
67     * @return <tt>true</tt> if security is enabled, <tt>false</tt> otherwise
68     */
69    public boolean isHBaseSecurityEnabled() {
70      return User.isHBaseSecurityEnabled(this.getConf());
71    }
72  
73    /**
74     * @return the current user within the current execution context
75     * @throws IOException if the user cannot be loaded
76     */
77    public User getCurrent() throws IOException {
78      return User.getCurrent();
79    }
80  
81    public User create(UserGroupInformation ugi) {
82      return User.create(ugi);
83    }
84  
85    /**
86     * Log in the current process using the given configuration keys for the credential file and login
87     * principal.
88     * <p>
89     * <strong>This is only applicable when running on secure Hadoop</strong> -- see
90     * org.apache.hadoop.security.SecurityUtil#login(Configuration,String,String,String). On regular
91     * Hadoop (without security features), this will safely be ignored.
92     * </p>
93     * @param conf The configuration data to use
94     * @param fileConfKey Property key used to configure path to the credential file
95     * @param principalConfKey Property key used to configure login principal
96     * @param localhost Current hostname to use in any credentials
97     * @throws IOException underlying exception from SecurityUtil.login() call
98     */
99    public void login(String fileConfKey, String principalConfKey, String localhost)
100       throws IOException {
101     User.login(getConf(), fileConfKey, principalConfKey, localhost);
102   }
103 
104   /**
105    * @return whether or not Kerberos authentication is configured for Hadoop. For non-secure Hadoop,
106    *         this always returns <code>false</code>. For secure Hadoop, it will return the value
107    *         from {@code UserGroupInformation.isSecurityEnabled()}.
108    */
109   public boolean isHadoopSecurityEnabled() {
110     return User.isSecurityEnabled();
111   }
112 }