content: /*
   * 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;
  
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.util.ShellUtils;
  import alluxio.util.network.NetworkAddressUtils;
  import alluxio.util.network.NetworkAddressUtils.ServiceType;
  
  import java.io.IOException;
  import java.net.ServerSocket;
  import java.util.Map;
  
  /**
   * Task for validating whether a specific port is available.
   */
  public final class PortAvailabilityValidationTask extends AbstractValidationTask {
    private final ServiceType mServiceType;
    private final String mOwner;
    private final AlluxioConfiguration mConf;
  
    /**
     * Creates a new instance of {@link PortAvailabilityValidationTask}.
     *
     * @param serviceType Alluxio network service whose port will be validated
     * @param owner Alluxio class name who owns the network service
     * @param conf configuration
     */
    public PortAvailabilityValidationTask(ServiceType serviceType, String owner,
                                          AlluxioConfiguration conf) {
      mServiceType = serviceType;
      mOwner = owner;
      mConf = conf;
    }
  
    @Override
    public String getName() {
      return "ValidateAlluxioPorts";
    }
  
    @Override
    public ValidationTaskResult validateImpl(Map<String, String> optionsMap) {
      StringBuilder msg = new StringBuilder();
      StringBuilder advice = new StringBuilder();
  
      if (ShellUtils.isAlluxioRunning(mOwner)) {
        msg.append(String.format("%s is already running. Skip validation.%n", mOwner));
        return new ValidationTaskResult(ValidationUtils.State.SKIPPED, getName(),
                msg.toString(), advice.toString());
      }
      int port = NetworkAddressUtils.getPort(mServiceType, mConf);
      if (!isLocalPortAvailable(port)) {
        msg.append(String.format("%s port %d is not available.%n",
                mServiceType.getServiceName(), port));
        advice.append(String.format("Please open your port %s for service %s.%n",
                port, mServiceType.getServiceName()));
        return new ValidationTaskResult(ValidationUtils.State.FAILED, getName(),
                msg.toString(), advice.toString());
      }
      msg.append("All ports are validated.\n");
      return new ValidationTaskResult(ValidationUtils.State.OK, getName(),
              msg.toString(), advice.toString());
    }
  
    private static boolean isLocalPortAvailable(int port) {
      try (ServerSocket socket = new ServerSocket(port)) {
        socket.setReuseAddress(true);
        return true;
      } catch (IOException e) {
        return false;
      }
    }
  }
  