alluxio-master-2.x/table/shell/src/main/java/alluxio/cli/table/command/DetachDatabaseCommand.java
/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.cli.table.command;

import alluxio.AlluxioURI;
import alluxio.cli.CommandUtils;
import alluxio.client.file.FileSystemContext;
import alluxio.client.table.TableMasterClient;
import alluxio.conf.AlluxioConfiguration;
import alluxio.conf.PropertyKey;
import alluxio.exception.status.AlluxioStatusException;
import alluxio.exception.status.InvalidArgumentException;
import alluxio.util.io.PathUtils;

import org.apache.commons.cli.CommandLine;

/**
 * This command removes a database from the table master.
 *
 * After calling this, the database and all table metadata is removed. To regain access to this
 * table, the corresponding {@link AttachDatabaseCommand} will need to be called again.
 */
public class DetachDatabaseCommand extends AbstractTableCommand {
  /**
   * Creates a new instance of {@link DetachDatabaseCommand}.
   *
   * @param conf alluxio configuration
   * @param client the table master client
   * @param fsContext the filesystem of Alluxio
   */
  public DetachDatabaseCommand(AlluxioConfiguration conf, TableMasterClient client,
      FileSystemContext fsContext) {
    super(conf, client, fsContext);
  }

  @Override
  public void validateArgs(CommandLine cli) throws InvalidArgumentException {
    CommandUtils.checkNumOfArgsEquals(this, cli, 1);
  }

  @Override
  public String getCommandName() {
    return "detachdb";
  }

  @Override
  public String getUsage() {
    return "detachdb <db name>";
  }

  @Override
  public String getDescription() {
    return "Detach a database with the given name from the Alluxio catalog master's namespace";
  }

  @Override
  public int run(CommandLine cli) throws AlluxioStatusException {
    String dbName = cli.getArgs()[0];
    if (mClient.detachDatabase(dbName)) {
      AlluxioURI path = new AlluxioURI(PathUtils
          .concatPath(mConf.get(PropertyKey.TABLE_CATALOG_PATH), dbName));
      System.out.println("Successfully detached db " + dbName
          + ". Please unmount and clean up the alluxio location at " + path
          + " before attaching another database named " + dbName);
    }
    return 0;
  }
}
