| /** |
| * 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.mapred.gridmix; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.fs.FileSystem; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.security.UserGroupInformation; |
| import org.apache.hadoop.util.LineReader; |
| |
| import java.io.IOException; |
| import java.net.URI; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| |
| public class RoundRobinUserResolver implements UserResolver { |
| public static final Log LOG = LogFactory.getLog(RoundRobinUserResolver.class); |
| |
| private int uidx = 0; |
| private List<UserGroupInformation> users = Collections.emptyList(); |
| private final HashMap<UserGroupInformation,UserGroupInformation> usercache = |
| new HashMap<UserGroupInformation,UserGroupInformation>(); |
| |
| /** |
| * Userlist assumes one UGI per line, each UGI matching |
| * <username>,<group>[,group]* |
| */ |
| private List<UserGroupInformation> parseUserList(URI userUri, |
| Configuration conf) |
| throws IOException { |
| if (null == userUri) { |
| return Collections.emptyList(); |
| } |
| |
| final Path userloc = new Path(userUri.toString()); |
| final Text rawUgi = new Text(); |
| final FileSystem fs = userloc.getFileSystem(conf); |
| final ArrayList<UserGroupInformation> ret = new ArrayList(); |
| |
| LineReader in = null; |
| try { |
| final ArrayList<String> groups = new ArrayList(); |
| in = new LineReader(fs.open(userloc)); |
| while (in.readLine(rawUgi) > 0) { |
| int e = rawUgi.find(","); |
| if (e <= 0) { |
| throw new IOException("Missing username: " + rawUgi); |
| } |
| final String username = Text.decode(rawUgi.getBytes(), 0, e); |
| int s = e; |
| while ((e = rawUgi.find(",", ++s)) != -1) { |
| groups.add(Text.decode(rawUgi.getBytes(), s, e - s)); |
| s = e; |
| } |
| groups.add(Text.decode(rawUgi.getBytes(), s, rawUgi.getLength() - s)); |
| if (groups.size() == 0) { |
| throw new IOException("Missing groups: " + rawUgi); |
| } |
| ret.add(UserGroupInformation.createRemoteUser(username)); |
| } |
| } finally { |
| if (in != null) { |
| in.close(); |
| } |
| } |
| return ret; |
| } |
| |
| @Override |
| public synchronized boolean setTargetUsers(URI userloc, Configuration conf) |
| throws IOException { |
| users = parseUserList(userloc, conf); |
| if (users.size() == 0) { |
| throw new IOException(buildEmptyUsersErrorMsg(userloc)); |
| } |
| usercache.keySet().retainAll(users); |
| return true; |
| } |
| |
| static String buildEmptyUsersErrorMsg(URI userloc) { |
| return "Empty user list is not allowed for RoundRobinUserResolver. Provided" |
| + " user resource URI '" + userloc + "' resulted in an empty user list."; |
| } |
| |
| @Override |
| public synchronized UserGroupInformation getTargetUgi( |
| UserGroupInformation ugi) { |
| UserGroupInformation ret = usercache.get(ugi); |
| if (null == ret) { |
| ret = users.get(uidx++ % users.size()); |
| usercache.put(ugi, ret); |
| } |
| UserGroupInformation val = null; |
| try { |
| val = |
| UserGroupInformation.createProxyUser(ret.getUserName(), |
| UserGroupInformation.getLoginUser()); |
| } catch (IOException e) { |
| LOG.error("Error while creating the proxy user " ,e); |
| } |
| return val; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * <p> |
| * {@link RoundRobinUserResolver} needs to map the users in the |
| * trace to the provided list of target users. So user list is needed. |
| */ |
| public boolean needsTargetUsersList() { |
| return true; |
| } |
| } |