org.apache.whirr.service.hadoop.HadoopConfigurationConverter.java Source code

Introduction

Here is the source code for org.apache.whirr.service.hadoop.HadoopConfigurationConverter.java

Source

/**
 * 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.whirr.service.hadoop;

import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Charsets;
import com.google.common.collect.Lists;
import com.google.common.io.Files;

import org.apache.commons.configuration.AbstractConfiguration;
import org.apache.commons.configuration.Configuration;
import org.apache.commons.lang.StringUtils;
import org.jclouds.scriptbuilder.domain.Statement;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.Map.Entry;

import static org.jclouds.scriptbuilder.domain.Statements.createOrOverwriteFile;

/**
 * Helper class to convert between Hadoop configuration representations.
 */
public class HadoopConfigurationConverter {

    private static final Logger LOG = LoggerFactory.getLogger(HadoopConfigurationConverter.class);

    private static final String FINAL_SUFFIX = ".final";

    @VisibleForTesting
    static List<String> asXmlConfigurationLines(Configuration hadoopConfig) {
        List<String> lines = Lists.newArrayList();
        lines.add("<configuration>");
        for (@SuppressWarnings("unchecked")
        Iterator<String> it = hadoopConfig.getKeys(); it.hasNext();) {
            String key = it.next();
            if (key.endsWith(FINAL_SUFFIX)) {
                continue;
            }

            // rebuild the original value by joining all of them with the default separator
            String value = StringUtils.join(hadoopConfig.getStringArray(key),
                    AbstractConfiguration.getDefaultListDelimiter());
            lines.add("  <property>");
            lines.add(String.format("    <name>%s</name>", key));
            lines.add(String.format("    <value>%s</value>", value));
            String finalValue = hadoopConfig.getString(key + FINAL_SUFFIX);
            if (finalValue != null) {
                lines.add(String.format("    <final>%s</final>", finalValue));
            }
            lines.add("  </property>");
        }
        lines.add("</configuration>");
        return lines;
    }

    public static Statement asCreateXmlConfigurationFileStatement(String path, Configuration hadoopConfig) {
        return createOrOverwriteFile(path, asXmlConfigurationLines(hadoopConfig));
    }

    @VisibleForTesting
    static List<String> asEnvironmentVariablesLines(Configuration hadoopConfig) {
        List<String> lines = Lists.newArrayList();
        lines.add(". /etc/profile");

        for (@SuppressWarnings("unchecked")
        Iterator<String> it = hadoopConfig.getKeys(); it.hasNext();) {
            String key = it.next();
            if (key.endsWith(FINAL_SUFFIX)) {
                continue;
            }

            // Write the export line. We only allow one value per key 
            String value = hadoopConfig.getString(key);
            lines.add(new StringBuilder("export ").append(key).append("=\"").append(value).append("\"").toString());
        }
        return lines;
    }

    public static Statement asCreateEnvironmentVariablesFileStatement(String path, Configuration config) {
        return createOrOverwriteFile(path, asEnvironmentVariablesLines(config));
    }

    private static CharSequence generateHadoopConfigurationFile(Properties config) {
        StringBuilder sb = new StringBuilder();
        sb.append("<?xml version=\"1.0\"?>\n");
        sb.append("<?xml-stylesheet type=\"text/xsl\" href=\"configuration.xsl\"?>\n");
        sb.append("<configuration>\n");
        for (Entry<Object, Object> entry : config.entrySet()) {
            sb.append("  <property>\n");
            sb.append("    <name>").append(entry.getKey()).append("</name>\n");
            sb.append("    <value>").append(entry.getValue()).append("</value>\n");
            sb.append("  </property>\n");
        }
        sb.append("</configuration>\n");
        return sb;
    }

    public static void createClientSideHadoopSiteFile(File file, Properties config) {
        try {
            Files.write(generateHadoopConfigurationFile(config), file, Charsets.UTF_8);
            LOG.info("Wrote file {}", file);
        } catch (IOException e) {
            LOG.error("Problem writing file {}", file, e);
        }
    }

}