content: /**
   * 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
   * <p/>
   * http://www.apache.org/licenses/LICENSE-2.0
   * <p/>
   * 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.atlas.impala.hook;
  
  import com.google.common.collect.Sets;
  import org.apache.atlas.hook.AtlasHook;
  import org.apache.atlas.impala.hook.events.BaseImpalaEvent;
  import org.apache.atlas.impala.hook.events.CreateImpalaProcess;
  import org.apache.atlas.impala.model.ImpalaOperationType;
  import org.apache.atlas.impala.model.ImpalaQuery;
  import org.apache.atlas.type.AtlasType;
  import org.apache.commons.lang.StringUtils;
  import org.apache.hadoop.security.UserGroupInformation;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import javax.security.auth.Subject;
  import javax.security.auth.kerberos.KerberosPrincipal;
  
  import java.io.IOException;
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.util.HashSet;
  
  import static org.apache.atlas.repository.Constants.IMPALA_SOURCE;
  
  public class ImpalaLineageHook extends AtlasHook {
      private static final Logger LOG = LoggerFactory.getLogger(ImpalaLineageHook.class);
      public static final String ATLAS_ENDPOINT                      = "atlas.rest.address";
      public static final String REALM_SEPARATOR                     = "@";
      public static final String CONF_PREFIX                         = "atlas.hook.impala.";
      public static final String CONF_REALM_NAME                     = "atlas.realm.name";
      public static final String HDFS_PATH_CONVERT_TO_LOWER_CASE     = CONF_PREFIX + "hdfs_path.convert_to_lowercase";
      public static final String DEFAULT_HOST_NAME                   = "localhost";
  
      private static final String  realm;
      private static final boolean convertHdfsPathToLowerCase;
      private static       String  hostName;
  
      static {
          realm                      = atlasProperties.getString(CONF_REALM_NAME, DEFAULT_CLUSTER_NAME);  // what should default be ??
          convertHdfsPathToLowerCase = atlasProperties.getBoolean(HDFS_PATH_CONVERT_TO_LOWER_CASE, false);
  
          try {
              hostName = InetAddress.getLocalHost().getHostName();
          } catch (UnknownHostException e) {
              LOG.warn("No hostname found. Setting the hostname to default value {}", DEFAULT_HOST_NAME, e);
              hostName = DEFAULT_HOST_NAME;
          }
      }
  
      public ImpalaLineageHook() {}
  
      public String getMessageSource() {
          return IMPALA_SOURCE;
      }
  
      public void process(String impalaQueryString) throws Exception {
          if (StringUtils.isEmpty(impalaQueryString)) {
              LOG.warn("==> ImpalaLineageHook.process skips because the impalaQueryString is empty <==");
              return;
          }
  
          ImpalaQuery lineageQuery = AtlasType.fromJson(impalaQueryString, ImpalaQuery.class);
          process(lineageQuery);
      }
  
      public void process(ImpalaQuery lineageQuery) throws Exception {
          if (lineageQuery == null) {
              LOG.warn("==> ImpalaLineageHook.process skips because the query object is null <==");
              return;
          }
  
          if (StringUtils.isEmpty(lineageQuery.getQueryText())) {
              LOG.warn("==> ImpalaLineageHook.process skips because the query text is empty <==");
              return;
          }
  
          if (LOG.isDebugEnabled()) {
              LOG.debug("==> ImpalaLineageHook.process({})", lineageQuery.getQueryText());
          }
  
          try {
              ImpalaOperationType operationType = ImpalaOperationParser.getImpalaOperationType(lineageQuery.getQueryText());
              AtlasImpalaHookContext context =
                      new AtlasImpalaHookContext(this, operationType, lineageQuery);
              BaseImpalaEvent event = null;
  
              switch (operationType) {
                  case CREATEVIEW:
                  case CREATETABLE_AS_SELECT:
                  case ALTERVIEW_AS:
                  case QUERY:
                  case QUERY_WITH_CLAUSE:
                      event = new CreateImpalaProcess(context);
                      break;
                  default:
                      if (LOG.isDebugEnabled()) {
                          LOG.debug("HiveHook.run({}): operation ignored", lineageQuery.getQueryText());
                      }
                      break;
              }
  
              if (event != null) {
                  LOG.debug("Processing event: " + lineageQuery.getQueryText());
  
                  final UserGroupInformation ugi = getUgiFromUserName(lineageQuery.getUser());
  
                  super.notifyEntities(event.getNotificationMessages(), ugi);
              }
          } catch (Throwable t) {
              LOG.error("ImpalaLineageHook.process(): failed to process query {}",
                      AtlasType.toJson(lineageQuery), t);
          }
  
          if (LOG.isDebugEnabled()) {
              LOG.debug("<== ImpalaLineageHook.process({})", lineageQuery.getQueryText());
          }
      }
  
      public String getHostName() {
          return hostName;
      }
  
      private UserGroupInformation getUgiFromUserName(String userName)  throws IOException {
          String userPrincipal = userName.contains(REALM_SEPARATOR) ? userName : userName + "@" + getRealm();
          Subject userSubject = new Subject(false, Sets.newHashSet(
                  new KerberosPrincipal(userPrincipal)), new HashSet<Object>(), new HashSet<Object>());
          return UserGroupInformation.getUGIFromSubject(userSubject);
      }
  
      public String getRealm() {
          return realm;
      }
  
      public boolean isConvertHdfsPathToLowerCase() {
          return convertHdfsPathToLowerCase;
      }
  }
  