/***********************************************************************************************************************
 * Copyright (C) 2010-2014 by the Stratosphere project (http://stratosphere.eu)
 *
 * Licensed 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 eu.stratosphere.yarn;

import java.io.IOException;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.apache.hadoop.yarn.api.ApplicationConstants.Environment;

import eu.stratosphere.nephele.taskmanager.TaskManager;

public class YarnTaskManagerRunner {
	
	private static final Log LOG = LogFactory.getLog(YarnTaskManagerRunner.class);
	
	public static void main(final String[] args) throws IOException {
		Map<String, String> envs = System.getenv();
		final String yarnClientUsername = envs.get(Client.ENV_CLIENT_USERNAME);
		final String localDirs = envs.get(Environment.LOCAL_DIRS.key());
		
		// configure local directory
		final String[] newArgs = Arrays.copyOf(args, args.length + 2);
		newArgs[newArgs.length-2] = "-"+TaskManager.ARG_CONF_DIR;
		newArgs[newArgs.length-1] = localDirs;
		LOG.info("Setting log path "+localDirs);
		LOG.info("YARN daemon runs as '"+UserGroupInformation.getCurrentUser().getShortUserName()+"' setting"
				+ " user to execute Stratosphere TaskManager to '"+yarnClientUsername+"'");
		UserGroupInformation ugi = UserGroupInformation.createRemoteUser(yarnClientUsername);
		for(Token<? extends TokenIdentifier> toks : UserGroupInformation.getCurrentUser().getTokens()) {
			ugi.addToken(toks);
		}
		ugi.doAs(new PrivilegedAction<Object>() {
			@Override
			public Object run() {
				try {
					TaskManager.main(newArgs);
				} catch (Exception e) {
					e.printStackTrace();
				}
				return null;
			}
		});
	}
}