Java tutorial
/* * Copyright 2017 StreamSets Inc. * * Licensed 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 com.streamsets.datacollector.security; import com.streamsets.datacollector.stage.HadoopConfigurationUtils; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.security.UserGroupInformation; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.security.auth.Subject; import java.io.IOException; import java.security.AccessControlContext; import java.security.AccessController; public class DefaultLoginUgiProvider extends LoginUgiProvider { private static final Logger LOG = LoggerFactory.getLogger(DefaultLoginUgiProvider.class); @Override public UserGroupInformation getLoginUgi(Configuration hdfsConfiguration) throws IOException { AccessControlContext accessContext = AccessController.getContext(); Subject subject = Subject.getSubject(accessContext); UserGroupInformation loginUgi; //HADOOP-13805 HadoopConfigurationUtils.configureHadoopTreatSubjectExternal(hdfsConfiguration); UserGroupInformation.setConfiguration(hdfsConfiguration); if (UserGroupInformation.isSecurityEnabled()) { loginUgi = UserGroupInformation.getUGIFromSubject(subject); } else { UserGroupInformation.loginUserFromSubject(subject); loginUgi = UserGroupInformation.getLoginUser(); } if (LOG.isDebugEnabled()) { LOG.debug("Subject = {}, Principals = {}, Login UGI = {}", subject, subject == null ? "null" : subject.getPrincipals(), loginUgi); } return loginUgi; } }