- 1. 概述
传统的文件系统中,ACL分为两个维度,一个是属组,一个是权限,子目录/文件默认继承父目录的ACL。而在Zookeeper中,node的ACL是没有继承关系的,是独立控制的。Zookeeper的ACL,可以从三个维度来理解:一是scheme; 二是user; 三是permission,通常表示为scheme:id:permissions, 下面从这三个方面分别来介绍:
scheme: scheme对应于采用哪种方案来进行权限管理,zookeeper实现了一个pluggable的ACL方案,可以通过扩展scheme,来扩展ACL的机制。zookeeper-3.4.4缺省支持下面几种scheme:
- world: 它下面只有一个id, 叫anyone, world:anyone代表任何人,zookeeper中对所有人有权限的结点就是属于world:anyone的
- auth: 它不需要id, 只要是通过authentication的user都有权限(zookeeper支持通过kerberos来进行authencation, 也支持username/password形式的authentication)
- digest: 它对应的id为username:BASE64(SHA1(password)),它需要先通过username:password形式的authentication
- ip: 它对应的id为客户机的IP地址,设置的时候可以设置一个ip段,比如ip:192.168.1.0/16, 表示匹配前16个bit的IP段
- super: 在这种scheme情况下,对应的id拥有超级权限,可以做任何事情(cdrwa)
另外,zookeeper-3.4.4的代码中还提供了对sasl的支持,不过缺省是没有开启的,需要配置才能启用,具体怎么配置在下文中介绍。
- sasl: sasl的对应的id,是一个通过sasl authentication用户的id,zookeeper-3.4.4中的sasl authentication是通过kerberos来实现的,也就是说用户只有通过了kerberos认证,才能访问它有权限的node.
id: id与scheme是紧密相关的,具体的情况在上面介绍scheme的过程都已介绍,这里不再赘述。
permission: zookeeper目前支持下面一些权限:
- CREATE(c): 创建权限,可以在在当前node下创建child node
- DELETE(d): 删除权限,可以删除当前的node
- READ(r): 读权限,可以获取当前node的数据,可以list当前node所有的child nodes
- WRITE(w): 写权限,可以向当前node写数据
- ADMIN(a): 管理权限,可以设置当前node的permission
- 2. 实现
如前所述,在zookeeper中提供了一种pluggable的ACL机制。具体来说就是每种scheme对应于一种ACL机制,可以通过扩展scheme来扩展ACL的机制。在具体的实现中,每种scheme对应一种AuthenticationProvider。每种AuthenticationProvider实现了当前机制下authentication的检查,通过了authentication的检查,然后再进行统一的permission检查,如此便实现了ACL。所有的AuthenticationProvider都注册在ProviderRegistry中,新扩展的AuthenticationProvider可以通过配置注册到ProviderRegistry中去。下面是实施检查的具体实现:
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.EventType;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.ACL;
import org.apache.zookeeper.data.Stat;
/**
* Zookeeper 节点授权
*/
public class ZookeeperAuth implements Watcher {
/** 连接地址 */
final static String CONNECT_ADDR = "192.168.80.88:2181";
/** 测试路径 */
final static String PATH = "/testAuth";
final static String PATH_DEL = "/testAuth/delNode";
/** 认证类型 */
final static String authentication_type = "digest";
/** 认证正确方法 */
final static String correctAuthentication = "123456";
/** 认证错误方法 */
final static String badAuthentication = "654321";
static ZooKeeper zk = null;
/** 计时器 */
AtomicInteger seq = new AtomicInteger();
/** 标识 */
private static final String LOG_PREFIX_OF_MAIN = "【Main】";
private CountDownLatch connectedSemaphore = new CountDownLatch(1);
@Override
public void process(WatchedEvent event) {
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
if (event==null) {
return;
}
// 连接状态
KeeperState keeperState = event.getState();
// 事件类型
EventType eventType = event.getType();
// 受影响的path
String path = event.getPath();
String logPrefix = "【Watcher-" + this.seq.incrementAndGet() + "】";
System.out.println(logPrefix + "收到Watcher通知");
System.out.println(logPrefix + "连接状态:\t" + keeperState.toString());
System.out.println(logPrefix + "事件类型:\t" + eventType.toString());
if (KeeperState.SyncConnected == keeperState) {
// 成功连接上ZK服务器
if (EventType.None == eventType) {
System.out.println(logPrefix + "成功连接上ZK服务器");
connectedSemaphore.countDown();
}
} else if (KeeperState.Disconnected == keeperState) {
System.out.println(logPrefix + "与ZK服务器断开连接");
} else if (KeeperState.AuthFailed == keeperState) {
System.out.println(logPrefix + "权限检查失败");
} else if (KeeperState.Expired == keeperState) {
System.out.println(logPrefix + "会话失效");
}
System.out.println("--------------------------------------------");
}
/**
* 创建ZK连接
*
* @param connectString
* ZK服务器地址列表
* @param sessionTimeout
* Session超时时间
*/
public void createConnection(String connectString, int sessionTimeout) {
this.releaseConnection();
try {
zk = new ZooKeeper(connectString, sessionTimeout, this);
//添加节点授权
zk.addAuthInfo(authentication_type,correctAuthentication.getBytes());
System.out.println(LOG_PREFIX_OF_MAIN + "开始连接ZK服务器");
//倒数等待
connectedSemaphore.await();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 关闭ZK连接
*/
public void releaseConnection() {
if (this.zk!=null) {
try {
this.zk.close();
} catch (InterruptedException e) {
}
}
}
/**
*
* <B>方法名称:</B>测试函数<BR>
* <B>概要说明:</B>测试认证<BR>
* @param args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
ZookeeperAuth testAuth = new ZookeeperAuth();
testAuth.createConnection(CONNECT_ADDR,2000);
List<ACL> acls = new ArrayList<ACL>(1);
for (ACL ids_acl : Ids.CREATOR_ALL_ACL) {
acls.add(ids_acl);
}
try {
zk.create(PATH, "init content".getBytes(), acls, CreateMode.PERSISTENT);
System.out.println("使用授权key:" + correctAuthentication + "创建节点:"+ PATH + ", 初始内容是: init content");
} catch (Exception e) {
e.printStackTrace();
}
try {
zk.create(PATH_DEL, "will be deleted! ".getBytes(), acls, CreateMode.PERSISTENT);
System.out.println("使用授权key:" + correctAuthentication + "创建节点:"+ PATH_DEL + ", 初始内容是: init content");
} catch (Exception e) {
e.printStackTrace();
}
// 获取数据
getDataByNoAuthentication();
getDataByBadAuthentication();
getDataByCorrectAuthentication();
// 更新数据
updateDataByNoAuthentication();
updateDataByBadAuthentication();
updateDataByCorrectAuthentication();
// 删除数据
deleteNodeByBadAuthentication();
deleteNodeByNoAuthentication();
deleteNodeByCorrectAuthentication();
//
Thread.sleep(1000);
deleteParent();
//释放连接
testAuth.releaseConnection();
}
/** 获取数据:采用错误的密码 */
static void getDataByBadAuthentication() {
String prefix = "[使用错误的授权信息]";
try {
ZooKeeper badzk = new ZooKeeper(CONNECT_ADDR, 2000, null);
//授权
badzk.addAuthInfo(authentication_type,badAuthentication.getBytes());
Thread.sleep(2000);
System.out.println(prefix + "获取数据:" + PATH);
System.out.println(prefix + "成功获取数据:" + badzk.getData(PATH, false, null));
} catch (Exception e) {
System.err.println(prefix + "获取数据失败,原因:" + e.getMessage());
}
}
/** 获取数据:不采用密码 */
static void getDataByNoAuthentication() {
String prefix = "[不使用任何授权信息]";
try {
System.out.println(prefix + "获取数据:" + PATH);
ZooKeeper nozk = new ZooKeeper(CONNECT_ADDR, 2000, null);
Thread.sleep(2000);
System.out.println(prefix + "成功获取数据:" + nozk.getData(PATH, false, null));
} catch (Exception e) {
System.err.println(prefix + "获取数据失败,原因:" + e.getMessage());
}
}
/** 采用正确的密码 */
static void getDataByCorrectAuthentication() {
String prefix = "[使用正确的授权信息]";
try {
System.out.println(prefix + "获取数据:" + PATH);
System.out.println(prefix + "成功获取数据:" + zk.getData(PATH, false, null));
} catch (Exception e) {
System.out.println(prefix + "获取数据失败,原因:" + e.getMessage());
}
}
/**
* 更新数据:不采用密码
*/
static void updateDataByNoAuthentication() {
String prefix = "[不使用任何授权信息]";
System.out.println(prefix + "更新数据: " + PATH);
try {
ZooKeeper nozk = new ZooKeeper(CONNECT_ADDR, 2000, null);
Thread.sleep(2000);
Stat stat = nozk.exists(PATH, false);
if (stat!=null) {
nozk.setData(PATH, prefix.getBytes(), -1);
System.out.println(prefix + "更新成功");
}
} catch (Exception e) {
System.err.println(prefix + "更新失败,原因是:" + e.getMessage());
}
}
/**
* 更新数据:采用错误的密码
*/
static void updateDataByBadAuthentication() {
String prefix = "[使用错误的授权信息]";
System.out.println(prefix + "更新数据:" + PATH);
try {
ZooKeeper badzk = new ZooKeeper(CONNECT_ADDR, 2000, null);
//授权
badzk.addAuthInfo(authentication_type,badAuthentication.getBytes());
Thread.sleep(2000);
Stat stat = badzk.exists(PATH, false);
if (stat!=null) {
badzk.setData(PATH, prefix.getBytes(), -1);
System.out.println(prefix + "更新成功");
}
} catch (Exception e) {
System.err.println(prefix + "更新失败,原因是:" + e.getMessage());
}
}
/**
* 更新数据:采用正确的密码
*/
static void updateDataByCorrectAuthentication() {
String prefix = "[使用正确的授权信息]";
System.out.println(prefix + "更新数据:" + PATH);
try {
Stat stat = zk.exists(PATH, false);
if (stat!=null) {
zk.setData(PATH, prefix.getBytes(), -1);
System.out.println(prefix + "更新成功");
}
} catch (Exception e) {
System.err.println(prefix + "更新失败,原因是:" + e.getMessage());
}
}
/**
* 不使用密码 删除节点
*/
static void deleteNodeByNoAuthentication() throws Exception {
String prefix = "[不使用任何授权信息]";
try {
System.out.println(prefix + "删除节点:" + PATH_DEL);
ZooKeeper nozk = new ZooKeeper(CONNECT_ADDR, 2000, null);
Thread.sleep(2000);
Stat stat = nozk.exists(PATH_DEL, false);
if (stat!=null) {
nozk.delete(PATH_DEL,-1);
System.out.println(prefix + "删除成功");
}
} catch (Exception e) {
System.err.println(prefix + "删除失败,原因是:" + e.getMessage());
}
}
/**
* 采用错误的密码删除节点
*/
static void deleteNodeByBadAuthentication() throws Exception {
String prefix = "[使用错误的授权信息]";
try {
System.out.println(prefix + "删除节点:" + PATH_DEL);
ZooKeeper badzk = new ZooKeeper(CONNECT_ADDR, 2000, null);
//授权
badzk.addAuthInfo(authentication_type,badAuthentication.getBytes());
Thread.sleep(2000);
Stat stat = badzk.exists(PATH_DEL, false);
if (stat!=null) {
badzk.delete(PATH_DEL, -1);
System.out.println(prefix + "删除成功");
}
} catch (Exception e) {
System.err.println(prefix + "删除失败,原因是:" + e.getMessage());
}
}
/**
* 使用正确的密码删除节点
*/
static void deleteNodeByCorrectAuthentication() throws Exception {
String prefix = "[使用正确的授权信息]";
try {
System.out.println(prefix + "删除节点:" + PATH_DEL);
Stat stat = zk.exists(PATH_DEL, false);
if (stat!=null) {
zk.delete(PATH_DEL, -1);
System.out.println(prefix + "删除成功");
}
} catch (Exception e) {
System.out.println(prefix + "删除失败,原因是:" + e.getMessage());
}
}
/**
* 使用正确的密码删除节点
*/
static void deleteParent() throws Exception {
try {
Stat stat = zk.exists(PATH_DEL, false);
if (stat == null) {
zk.delete(PATH, -1);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
下节连接