org.apache.hadoop.hbase.stargate.auth.ZooKeeperAuthenticator.java Source code

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Here is the source code for org.apache.hadoop.hbase.stargate.auth.ZooKeeperAuthenticator.java

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/*
 * Copyright 2010 The Apache Software Foundation
 *
 * 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.hbase.stargate.auth;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlRootElement;

import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.stargate.Constants;
import org.apache.hadoop.hbase.stargate.User;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWrapper;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;

import com.sun.jersey.api.json.JSONConfiguration;
import com.sun.jersey.api.json.JSONJAXBContext;
import com.sun.jersey.api.json.JSONUnmarshaller;

/**
 * A simple authenticator module for ZooKeeper.
 * <pre>
 *   /stargate/
 *     users/
 *       &lt;token&gt;</pre> 
 * Where <tt>&lt;token&gt;</tt> is a JSON formatted user record with the keys
 * 'name' (String, required), 'token' (String, optional), 'admin' (boolean,
 * optional), and 'disabled' (boolean, optional).
 */
public class ZooKeeperAuthenticator extends Authenticator implements Constants {

    @XmlRootElement(name = "user")
    static class UserModel {
        @XmlAttribute
        public String name;
        @XmlAttribute
        public boolean admin = false;
        @XmlAttribute
        public boolean disabled = false;
    }

    final String usersZNode;
    ZooKeeperWrapper wrapper;
    final JSONJAXBContext context;
    final JSONUnmarshaller unmarshaller;

    private boolean ensureParentExists(final String znode) {
        int index = znode.lastIndexOf("/");
        if (index <= 0) { // Parent is root, which always exists.
            return true;
        }
        return ensureExists(znode.substring(0, index));
    }

    private boolean ensureExists(final String znode) {
        ZooKeeper zk = wrapper.getZooKeeper();
        try {
            Stat stat = zk.exists(znode, false);
            if (stat != null) {
                return true;
            }
            zk.create(znode, new byte[0], Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            return true;
        } catch (KeeperException.NodeExistsException e) {
            return true; // ok, move on.
        } catch (KeeperException.NoNodeException e) {
            return ensureParentExists(znode) && ensureExists(znode);
        } catch (KeeperException e) {
        } catch (InterruptedException e) {
        }
        return false;
    }

    /**
     * Constructor
     * @param conf
     * @throws IOException
     */
    public ZooKeeperAuthenticator(HBaseConfiguration conf) throws IOException {
        this(conf, new ZooKeeperWrapper(conf, new Watcher() {
            public void process(WatchedEvent event) {
            }
        }));
        ensureExists(USERS_ZNODE_ROOT);
    }

    /**
     * Constructor
     * @param conf
     * @param wrapper
     * @throws IOException 
     */
    public ZooKeeperAuthenticator(HBaseConfiguration conf, ZooKeeperWrapper wrapper) throws IOException {
        this.usersZNode = conf.get("stargate.auth.zk.users", USERS_ZNODE_ROOT);
        this.wrapper = wrapper;
        try {
            this.context = new JSONJAXBContext(JSONConfiguration.natural().build(), UserModel.class);
            this.unmarshaller = context.createJSONUnmarshaller();
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

    @Override
    public User getUserForToken(String token) throws IOException {
        ZooKeeper zk = wrapper.getZooKeeper();
        try {
            byte[] data = zk.getData(usersZNode + "/" + token, null, null);
            if (data == null) {
                return null;
            }
            UserModel model = unmarshaller.unmarshalFromJSON(new ByteArrayInputStream(data), UserModel.class);
            return new User(model.name, token, model.admin, model.disabled);
        } catch (KeeperException.NoNodeException e) {
            return null;
        } catch (Exception e) {
            throw new IOException(e);
        }
    }

}