/*
* 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.flink.api.java.hadoop.mapred.utils;
import java.io.File;
import java.lang.reflect.Constructor;
import java.util.Collection;
import java.util.Map;
import org.apache.flink.annotation.Internal;
import org.apache.flink.configuration.ConfigConstants;
import org.apache.flink.configuration.GlobalConfiguration;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.JobContext;
import org.apache.hadoop.mapred.JobID;
import org.apache.hadoop.mapred.TaskAttemptContext;
import org.apache.hadoop.mapred.TaskAttemptID;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Utility class to work with Apache Hadoop MapRed classes.
*/
@Internal
public final class HadoopUtils {
private static final Logger LOG = LoggerFactory.getLogger(HadoopUtils.class);
private static final Text HDFS_DELEGATION_TOKEN_KIND = new Text("HDFS_DELEGATION_TOKEN");
/**
* Merge HadoopConfiguration into JobConf. This is necessary for the HDFS configuration.
*/
public static void mergeHadoopConf(JobConf jobConf) {
org.apache.hadoop.conf.Configuration hadoopConf = getHadoopConfiguration();
for (Map.Entry<String, String> e : hadoopConf) {
if (jobConf.get(e.getKey()) == null) {
jobConf.set(e.getKey(), e.getValue());
}
}
}
public static JobContext instantiateJobContext(JobConf jobConf, JobID jobId) throws Exception {
try {
// for Hadoop 1.xx
Class<?> clazz = null;
if(!TaskAttemptContext.class.isInterface()) {
clazz = Class.forName("org.apache.hadoop.mapred.JobContext", true, Thread.currentThread().getContextClassLoader());
}
// for Hadoop 2.xx
else {
clazz = Class.forName("org.apache.hadoop.mapred.JobContextImpl", true, Thread.currentThread().getContextClassLoader());
}
Constructor<?> constructor = clazz.getDeclaredConstructor(JobConf.class, org.apache.hadoop.mapreduce.JobID.class);
// for Hadoop 1.xx
constructor.setAccessible(true);
JobContext context = (JobContext) constructor.newInstance(jobConf, jobId);
return context;
} catch(Exception e) {
throw new Exception("Could not create instance of JobContext.", e);
}
}
public static TaskAttemptContext instantiateTaskAttemptContext(JobConf jobConf, TaskAttemptID taskAttemptID) throws Exception {
try {
// for Hadoop 1.xx
Class<?> clazz = null;
if(!TaskAttemptContext.class.isInterface()) {
clazz = Class.forName("org.apache.hadoop.mapred.TaskAttemptContext", true, Thread.currentThread().getContextClassLoader());
}
// for Hadoop 2.xx
else {
clazz = Class.forName("org.apache.hadoop.mapred.TaskAttemptContextImpl", true, Thread.currentThread().getContextClassLoader());
}
Constructor<?> constructor = clazz.getDeclaredConstructor(JobConf.class, TaskAttemptID.class);
// for Hadoop 1.xx
constructor.setAccessible(true);
TaskAttemptContext context = (TaskAttemptContext) constructor.newInstance(jobConf, taskAttemptID);
return context;
} catch(Exception e) {
throw new Exception("Could not create instance of TaskAttemptContext.", e);
}
}
/**
* Returns a new Hadoop Configuration object using the path to the hadoop conf configured
* in the main configuration (flink-conf.yaml).
* This method is public because its being used in the HadoopDataSource.
*/
public static org.apache.hadoop.conf.Configuration getHadoopConfiguration() {
org.apache.flink.configuration.Configuration flinkConfiguration =
GlobalConfiguration.loadConfiguration();
Configuration retConf = new org.apache.hadoop.conf.Configuration();
// We need to load both core-site.xml and hdfs-site.xml to determine the default fs path and
// the hdfs configuration
// Try to load HDFS configuration from Hadoop's own configuration files
// 1. approach: Flink configuration
final String hdfsDefaultPath = flinkConfiguration.getString(ConfigConstants
.HDFS_DEFAULT_CONFIG, null);
if (hdfsDefaultPath != null) {
retConf.addResource(new org.apache.hadoop.fs.Path(hdfsDefaultPath));
} else {
LOG.debug("Cannot find hdfs-default configuration file");
}
final String hdfsSitePath = flinkConfiguration.getString(ConfigConstants.HDFS_SITE_CONFIG, null);
if (hdfsSitePath != null) {
retConf.addResource(new org.apache.hadoop.fs.Path(hdfsSitePath));
} else {
LOG.debug("Cannot find hdfs-site configuration file");
}
// 2. Approach environment variables
String[] possibleHadoopConfPaths = new String[4];
possibleHadoopConfPaths[0] = flinkConfiguration.getString(ConfigConstants.PATH_HADOOP_CONFIG, null);
possibleHadoopConfPaths[1] = System.getenv("HADOOP_CONF_DIR");
if (System.getenv("HADOOP_HOME") != null) {
possibleHadoopConfPaths[2] = System.getenv("HADOOP_HOME")+"/conf";
possibleHadoopConfPaths[3] = System.getenv("HADOOP_HOME")+"/etc/hadoop"; // hadoop 2.2
}
for (String possibleHadoopConfPath : possibleHadoopConfPaths) {
if (possibleHadoopConfPath != null) {
if (new File(possibleHadoopConfPath).exists()) {
if (new File(possibleHadoopConfPath + "/core-site.xml").exists()) {
retConf.addResource(new org.apache.hadoop.fs.Path(possibleHadoopConfPath + "/core-site.xml"));
if (LOG.isDebugEnabled()) {
LOG.debug("Adding " + possibleHadoopConfPath + "/core-site.xml to hadoop configuration");
}
}
if (new File(possibleHadoopConfPath + "/hdfs-site.xml").exists()) {
retConf.addResource(new org.apache.hadoop.fs.Path(possibleHadoopConfPath + "/hdfs-site.xml"));
if (LOG.isDebugEnabled()) {
LOG.debug("Adding " + possibleHadoopConfPath + "/hdfs-site.xml to hadoop configuration");
}
}
}
}
}
return retConf;
}
/**
* Indicates whether the current user has an HDFS delegation token.
*/
public static boolean hasHDFSDelegationToken() throws Exception {
UserGroupInformation loginUser = UserGroupInformation.getCurrentUser();
Collection<Token<? extends TokenIdentifier>> usrTok = loginUser.getTokens();
for (Token<? extends TokenIdentifier> token : usrTok) {
if (token.getKind().equals(HDFS_DELEGATION_TOKEN_KIND)) {
return true;
}
}
return false;
}
/**
* Private constructor to prevent instantiation.
*/
private HadoopUtils() {
throw new RuntimeException();
}
}