1 /**
2 * Copyright 2010 The Apache Software Foundation
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing, software
15 * distributed under the License is distributed on an "AS IS" BASIS,
16 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17 * See the License for the specific language governing permissions and
18 * limitations under the License.
19 */
20
21 package org.apache.hadoop.hbase.zookeeper;
22
23 import java.util.Properties;
24 import java.util.Map.Entry;
25
26 import org.apache.hadoop.conf.Configuration;
27 import org.apache.hadoop.hbase.HBaseConfiguration;
28
29 /**
30 * Tool for reading a ZooKeeper server from HBase XML configuration producing
31 * the '-server host:port' argument to pass ZooKeeperMain. This program
32 * emits either '-server HOST:PORT" where HOST is one of the zk ensemble
33 * members plus zk client port OR it emits '' if no zk servers found (Yes,
34 * it emits '-server' too).
35 */
36 public class ZooKeeperMainServerArg {
37 public String parse(final Configuration c) {
38 // Note that we do not simply grab the property
39 // HConstants.ZOOKEEPER_QUORUM from the HBaseConfiguration because the
40 // user may be using a zoo.cfg file.
41 Properties zkProps = ZKConfig.makeZKProps(c);
42 String host = null;
43 String clientPort = null;
44 for (Entry<Object, Object> entry: zkProps.entrySet()) {
45 String key = entry.getKey().toString().trim();
46 String value = entry.getValue().toString().trim();
47 if (key.startsWith("server.") && host == null) {
48 String[] parts = value.split(":");
49 host = parts[0];
50 } else if (key.endsWith("clientPort")) {
51 clientPort = value;
52 }
53 if (host != null && clientPort != null) break;
54 }
55 return host != null && clientPort != null? host + ":" + clientPort: null;
56 }
57
58 /**
59 * Run the tool.
60 * @param args Command line arguments. First arg is path to zookeepers file.
61 */
62 public static void main(String args[]) {
63 Configuration conf = HBaseConfiguration.create();
64 String hostport = new ZooKeeperMainServerArg().parse(conf);
65 System.out.println((hostport == null || hostport.length() == 0)? "":
66 "-server " + hostport);
67 }
68 }