/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hdfs.server.namenode;

import static org.junit.Assert.assertTrue;

import java.net.InetSocketAddress;
import java.net.URL;

import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.DFSTestUtil;
import org.apache.hadoop.hdfs.HdfsConfiguration;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
import org.junit.Test;

/**
 * DFS_HOSTS and DFS_HOSTS_EXCLUDE tests
 * 
 */
public class TestHostsFiles {
  private static final Log LOG =
    LogFactory.getLog(TestHostsFiles.class.getName());

  /*
   * Return a configuration object with low timeouts for testing and 
   * a topology script set (which enables rack awareness).  
   */
  private Configuration getConf() {
    Configuration conf = new HdfsConfiguration();

    // Lower the heart beat interval so the NN quickly learns of dead
    // or decommissioned DNs and the NN issues replication and invalidation
    // commands quickly (as replies to heartbeats)
    conf.setLong(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY, 1L);

    // Have the NN ReplicationMonitor compute the replication and
    // invalidation commands to send DNs every second.
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_INTERVAL_KEY, 1);

    // Have the NN check for pending replications every second so it
    // quickly schedules additional replicas as they are identified.
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_PENDING_TIMEOUT_SEC_KEY, 1);

    // The DNs report blocks every second.
    conf.setLong(DFSConfigKeys.DFS_BLOCKREPORT_INTERVAL_MSEC_KEY, 1000L);

    // Indicates we have multiple racks
    conf.set(DFSConfigKeys.NET_TOPOLOGY_SCRIPT_FILE_NAME_KEY, "xyz");
    return conf;
  }

  @Test
  public void testHostsExcludeDfshealthJsp() throws Exception {
    Configuration conf = getConf();
    short REPLICATION_FACTOR = 2;
    final Path filePath = new Path("/testFile");

    // Configure an excludes file
    FileSystem localFileSys = FileSystem.getLocal(conf);
    Path workingDir = localFileSys.getWorkingDirectory();
    Path dir = new Path(workingDir, "build/test/data/temp/decommission");
    Path excludeFile = new Path(dir, "exclude");
    Path includeFile = new Path(dir, "include");
    assertTrue(localFileSys.mkdirs(dir));
    DFSTestUtil.writeFile(localFileSys, excludeFile, "");
    DFSTestUtil.writeFile(localFileSys, includeFile, "");
    conf.set(DFSConfigKeys.DFS_HOSTS_EXCLUDE, excludeFile.toUri().getPath());
    conf.set(DFSConfigKeys.DFS_HOSTS, includeFile.toUri().getPath());

    // Two blocks and four racks
    String racks[] = {"/rack1", "/rack1", "/rack2", "/rack2"};
    MiniDFSCluster cluster = new MiniDFSCluster.Builder(conf)
      .numDataNodes(racks.length).racks(racks).build();
    final FSNamesystem ns = cluster.getNameNode().getNamesystem();

    try {
      // Create a file with one block
      final FileSystem fs = cluster.getFileSystem();
      DFSTestUtil.createFile(fs, filePath, 1L, REPLICATION_FACTOR, 1L);
      ExtendedBlock b = DFSTestUtil.getFirstBlock(fs, filePath);
      DFSTestUtil.waitForReplication(cluster, b, 2, REPLICATION_FACTOR, 0);

      // Decommission one of the hosts with the block, this should cause 
      // the block to get replicated to another host on the same rack,
      // otherwise the rack policy is violated.
      BlockLocation locs[] = fs.getFileBlockLocations(
          fs.getFileStatus(filePath), 0, Long.MAX_VALUE);
      String name = locs[0].getNames()[0];
      String names = name + "\n" + "localhost:42\n";
      LOG.info("adding '" + names + "' to exclude file " + excludeFile.toUri().getPath());
      DFSTestUtil.writeFile(localFileSys, excludeFile, name);
      ns.getBlockManager().getDatanodeManager().refreshNodes(conf);
      DFSTestUtil.waitForDecommission(fs, name);

      // Check the block still has sufficient # replicas across racks
      DFSTestUtil.waitForReplication(cluster, b, 2, REPLICATION_FACTOR, 0);
      
      InetSocketAddress nnHttpAddress = cluster.getNameNode().getHttpAddress();
      LOG.info("nnaddr = '" + nnHttpAddress + "'");
      String nnHostName = nnHttpAddress.getHostName();
      URL nnjsp = new URL("http://" + nnHostName + ":" + nnHttpAddress.getPort() + "/dfshealth.jsp");
      LOG.info("fetching " + nnjsp);
      String dfshealthPage = StringEscapeUtils.unescapeHtml(DFSTestUtil.urlGet(nnjsp));
      LOG.info("got " + dfshealthPage);
      assertTrue("dfshealth should contain " + nnHostName + ", got:" + dfshealthPage,
          dfshealthPage.contains(nnHostName));

    } finally {
      cluster.shutdown();
    }
  }
}