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 */
018package org.apache.hadoop.hbase.chaos.actions;
019
020import java.io.IOException;
021import java.io.InterruptedIOException;
022import java.security.PrivilegedExceptionAction;
023import org.apache.hadoop.conf.Configuration;
024import org.apache.hadoop.fs.FileSystem;
025import org.apache.hadoop.fs.Path;
026import org.apache.hadoop.hbase.util.CommonFSUtils;
027import org.apache.hadoop.hdfs.DistributedFileSystem;
028import org.apache.hadoop.security.UserGroupInformation;
029
030/**
031 * Configuration common across the HDFS Actions.
032 */
033public final class HdfsActionUtils {
034
035  private HdfsActionUtils() {
036  }
037
038  /**
039   * Specify a user as whom HDFS actions should be run. The chaos process must have permissions
040   * sufficient to assume the role of the specified user.
041   * @see <a href=
042   *      "https://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-common/Superusers.html">Proxy
043   *      user - Superusers Acting On Behalf Of Other Users</a>
044   */
045  public static final String HDFS_USER_CONF_KEY = "org.apache.hadoop.hbase.chaos.actions.hdfs_user";
046
047  private static DistributedFileSystem createUnproxiedDfs(final Configuration conf)
048    throws IOException {
049    final Path rootDir = CommonFSUtils.getRootDir(conf);
050    final FileSystem fs = rootDir.getFileSystem(conf);
051    return (DistributedFileSystem) fs;
052  }
053
054  /**
055   * Create an instance of {@link DistributedFileSystem} that honors {@value HDFS_USER_CONF_KEY}.
056   */
057  static DistributedFileSystem createDfs(final Configuration conf) throws IOException {
058    final String proxyUser = conf.get(HDFS_USER_CONF_KEY);
059    if (proxyUser == null) {
060      return createUnproxiedDfs(conf);
061    }
062    final UserGroupInformation proxyUgi =
063      UserGroupInformation.createProxyUser(proxyUser, UserGroupInformation.getLoginUser());
064    try {
065      return proxyUgi
066        .doAs((PrivilegedExceptionAction<DistributedFileSystem>) () -> createUnproxiedDfs(conf));
067    } catch (InterruptedException e) {
068      final InterruptedIOException iioe = new InterruptedIOException(e.getMessage());
069      iioe.setStackTrace(e.getStackTrace());
070      throw iioe;
071    }
072  }
073}