Apache Sentry虽然可以将HDFS、Hive与Impala三个组件的权限认证统一，但是只能按照给组授予角色的方式来进行授权，不能直接授权给组中的用户，显得不太灵活。有时候为了兼容已有大数据平台的授权体系，比如只使用Sentry控制Impala服务的权限，而不控制Hive和HDFS服务的权限，希望通过调用Sentry客户端API的方式将已有的Hive和HDFS服务的权限信息导入到Sentry中，就需要通过调用Sentry API来达到这个目的。Sentry支持通过调用服务方式整合公司特定的数据权限需求，提供了外调接口来动态获得和更改权限信息，使我们可以同步其它大数据平台的组织架构，复用已有的权限模型，实现权限信息的统一。
环境
Impala版本：2.12.0-cdh5.16.1
Sentry版本：1.5.1-cdh5.16.1
JDK版本：jdk1.8.0_212
整合步骤
首先得确认Sentry服务端安装好并已启动，以下是整合步骤及测试用例。整个工程目录如下：
1、加入maven依赖：
<dependency>
<groupId>org.apache.sentry</groupId>
<artifactId>sentry-provider-db</artifactId>
<version>1.5.1-cdh5.16.1</version>
</dependency>
2、Sentry客户端配置文件——sentry-site.xml：
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
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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
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See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- WARNING!!! This file is provided for documentation purposes ONLY! -->
<!-- WARNING!!! You should copy to sentry-site.xml and make modification instead. -->
<configuration>
<property>
<name>sentry.service.client.server.rpc-port</name>
<value>8038</value>
</property>
<property>
<name>sentry.service.client.server.rpc-addresses</name>
<value>hadoop21-test1-rgtj5-tj1</value>
</property>
<property>
<name>sentry.service.client.server.rpc-connection-timeout</name>
<value>200000</value>
</property>
<!-- Properties required for setting the DB provider-->
<property>
<name>sentry.hive.provider.backend</name>
<value>org.apache.sentry.provider.db.SimpleDBProviderBackend</value>
</property>
<property>
<name>sentry.service.security.mode</name>
<value>none</value>
</property>
</configuration>
3、异常处理类——InternalException：
public class InternalException extends Exception{
public InternalException(String msg, Throwable cause) {
super(msg, cause);
}
public InternalException(String msg) {
super(msg);
}
}
4、配置文件加载类——SentryConfig：
public class SentryConfig {
// Absolute path to the sentry-site.xml configuration file.
private final String configFile_;
// The Sentry configuration. Valid only after calling loadConfig().
private final Configuration config_;
public SentryConfig(String configFilePath) {
configFile_ = configFilePath;
config_ = new Configuration();
}
/**
* Initializes the Sentry configuration.
*/
public void loadConfig() {
if (Strings.isNullOrEmpty(configFile_)) {
throw new IllegalArgumentException("A valid path to a sentry-site.xml config " +
"file must be set using --sentry_config to enable authorization.");
}
File configFile = new File(configFile_);
if (!configFile.exists()) {
String configFilePath = "\"" + configFile_ + "\"";
throw new RuntimeException("Sentry configuration file does not exist: " +
configFilePath);
}
if (!configFile.canRead()) {
throw new RuntimeException("Cannot read Sentry configuration file: " +
configFile_);
}
// Load the config.
try {
config_.addResource(configFile.toURI().toURL());
} catch (MalformedURLException e) {
throw new RuntimeException("Invalid Sentry config file path: " + configFile_, e);
}
}
public Configuration getConfig() { return config_; }
public String getConfigFile() { return configFile_; }
}
5、测试类——SentryClientTest：
public class SentryClientTest {
// SentryConfig类需要的sentry配置文件路径视配置文件实际存放路径而定
private static SentryConfig sentryConfig = new SentryConfig("/test/spring-boot-galaxy/bigdata-galaxy/src/test/scala/com/galaxy/bigdata/sentry/sentry-site-client.xml");
/**
* 测试获取已有角色信息
* @throws InternalException
*/
@Test
public void testListRoles() throws InternalException {
SentryServiceClient client = null;
try {
client = new SentryServiceClient();
// 这里为了测试方便，使用hadoop管理员作为请求用户，来获取所有角色信息
Set<TSentryRole> roles = client.get().listRoles("hadoop");
for (TSentryRole role : roles) {
System.out.println(role);
}
} catch (InternalException | SentryUserException e) {
e.printStackTrace();
} finally {
client.close();
}
}
/**
* 删除已有角色信息
* @throws InternalException
*/
@Test
public void testDropRoleIfExists() throws InternalException {
SentryServiceClient client = null;
try {
client = new SentryServiceClient();
client.get().dropRoleIfExists("hadoop","admin_role");
} catch (InternalException | SentryUserException e) {
e.printStackTrace();
} finally {
client.close();
}
}
/**
* Wrapper around a SentryPolicyServiceClient.
* TODO: When SENTRY-296 is resolved we can more easily cache connections instead of
* opening a new connection for each request.
*/
static class SentryServiceClient implements AutoCloseable {
private final SentryPolicyServiceClient client_;
/**
* Creates and opens a new Sentry Service thrift client.
*/
public SentryServiceClient() throws InternalException {
client_ = createClient();
}
/**
* Get the underlying SentryPolicyServiceClient.
*/
public SentryPolicyServiceClient get() {
return client_;
}
/**
* Returns this client back to the connection pool. Can be called multiple times.
*/
public void close() throws InternalException {
try {
client_.close();
} catch (Exception e) {
throw new InternalException("Error closing client: ", e);
}
}
/**
* Creates a new client to the SentryService.
*/
private SentryPolicyServiceClient createClient() throws InternalException {
SentryPolicyServiceClient client;
try {
sentryConfig.loadConfig();
client = SentryServiceClientFactory.create(sentryConfig.getConfig());
} catch (Exception e) {
throw new InternalException("Error creating Sentry Service client: ", e);
}
return client;
}
}
}
在该类中，定义了静态内部类SentryServiceClient，它的主要职责是创建SentryPolicyServiceClient接口的对象，SentryPolicyServiceClient接口是Sentry与外部系统交互的窗口，它的主要方法定义如下：
可以看到，创建（create）、删除（drop）、查询（list）、授权（grant）和撤销（revoke）这些与权限有关的操作，都定义在该方法中，方法的定义一目了然，顾名就能思义。
6、运行SentryClientTest类，测试服务调用是否正常，相关操作是否成功。
参考资料
1、Impala-2.12.0-cdh5.16.1源码SentryPolicyService.java类中的实现。
