org.apache.ambari.view.filebrowser.HdfsService.java Source code

Introduction

Here is the source code for org.apache.ambari.view.filebrowser.HdfsService.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.ambari.view.filebrowser;

import javax.xml.bind.annotation.XmlRootElement;

import org.apache.ambari.view.ViewContext;
import org.apache.ambari.view.filebrowser.utils.MisconfigurationFormattedException;
import org.apache.ambari.view.filebrowser.utils.ServiceFormattedException;
import org.apache.hadoop.security.UserGroupInformation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * Base Hdfs service
 */
public abstract class HdfsService {

    protected static final Logger logger = LoggerFactory.getLogger(HdfsService.class);

    protected final ViewContext context;

    /**
     * Constructor
     * @param context View Context instance
     */
    public HdfsService(ViewContext context) {
        this.context = context;
    }

    /**
     * Wrapper for json mapping of bool response
     */
    @XmlRootElement
    public static class BoolResult {
        public boolean success;

        public BoolResult(boolean success) {
            this.success = success;
        }
    }

    private HdfsApi _api = null;

    /**
     * Ger HdfsApi instance
     * @param context View Context instance
     * @return HdfsApi business delegate
     */
    public HdfsApi getApi(ViewContext context) {
        if (_api == null) {
            //      Thread.currentThread().setContextClassLoader(null);
            String defaultFs = context.getProperties().get("webhdfs.url");
            if (defaultFs == null)
                throw new MisconfigurationFormattedException("webhdfs.url");
            try {
                _api = new HdfsApi(defaultFs, getDoAsUsername(context), getHdfsAuthParams(context));
            } catch (Exception ex) {
                throw new ServiceFormattedException("HdfsApi connection failed. Check \"webhdfs.url\" property",
                        ex);
            }
        }
        return _api;
    }

    private static Map<String, String> getHdfsAuthParams(ViewContext context) {
        String auth = context.getProperties().get("webhdfs.auth");
        Map<String, String> params = new HashMap<String, String>();
        if (auth == null || auth.isEmpty()) {
            auth = "auth=SIMPLE";
        }
        for (String param : auth.split(";")) {
            String[] keyvalue = param.split("=");
            if (keyvalue.length != 2) {
                logger.error("Can not parse authentication param " + param + " in " + auth);
                continue;
            }
            params.put(keyvalue[0], keyvalue[1]);
        }
        return params;
    }

    /**
     * Get doAs username to use in HDFS
     * @param context View Context instance
     * @return user name
     */
    public String getDoAsUsername(ViewContext context) {
        String username = context.getProperties().get("webhdfs.username");
        if (username == null || username.isEmpty())
            username = context.getUsername();
        return username;
    }

    /**
     * Get proxyuser username to use in HDFS
     * @param context View Context instance
     * @return user name
     */
    public String getRealUsername(ViewContext context) {
        String username = context.getProperties().get("webhdfs.proxyuser");
        if (username == null || username.isEmpty())
            try {
                username = UserGroupInformation.getCurrentUser().getShortUserName();
            } catch (IOException e) {
                throw new ServiceFormattedException("HdfsApi connection failed. Can't get current user", e);
            }
        return username;
    }
}