| // 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 |
| // |
| // 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. |
| |
| using System; |
| using System.Collections.Generic; |
| using System.Diagnostics; |
| using System.IO; |
| using System.Linq; |
| using System.Text; |
| using Org.Apache.REEF.Tang.Annotations; |
| using Org.Apache.REEF.Utilities.Diagnostics; |
| using Org.Apache.REEF.Utilities.Logging; |
| |
| namespace Org.Apache.REEF.Client.Yarn |
| { |
| /// <summary> |
| /// Helper class to interact with the YARN command line. |
| /// </summary> |
| internal sealed class YarnCommandLineEnvironment : IYarnCommandLineEnvironment |
| { |
| private static readonly Logger Logger = Logger.GetLogger(typeof(YarnCommandLineEnvironment)); |
| |
| [Inject] |
| private YarnCommandLineEnvironment() |
| { |
| } |
| |
| /// <summary> |
| /// Returns the class path returned by `yarn classpath`. |
| /// </summary> |
| /// <returns>The class path returned by `yarn classpath`.</returns> |
| public IReadOnlyList<string> GetYarnClasspathList() |
| { |
| return Yarn("classpath").Split(';').Distinct().ToList(); |
| } |
| |
| /// <summary> |
| /// Returns the full Path to HADOOP_HOME |
| /// </summary> |
| /// <returns>The full Path to HADOOP_HOME</returns> |
| private string GetHadoopHomePath() |
| { |
| var path = Environment.GetEnvironmentVariable("HADOOP_HOME"); |
| if (string.IsNullOrWhiteSpace(path)) |
| { |
| var ex = new FileNotFoundException("HADOOP_HOME isn't set."); |
| Exceptions.Throw(ex, Logger); |
| throw ex; |
| } |
| |
| var fullPath = Path.GetFullPath(path); |
| |
| if (!Directory.Exists(fullPath)) |
| { |
| var ex = new FileNotFoundException("HADOOP_HOME points to [" + fullPath + "] which doesn't exist."); |
| Exceptions.Throw(ex, Logger); |
| throw ex; |
| } |
| return fullPath; |
| } |
| |
| /// <summary> |
| /// Returns the full Path to the `yarn.cmd` file. |
| /// </summary> |
| /// <returns>The full Path to the `yarn.cmd` file.</returns> |
| private string GetYarnCommandPath() |
| { |
| var result = Path.Combine(GetHadoopHomePath(), "bin", "yarn.cmd"); |
| if (!File.Exists(result)) |
| { |
| var ex = new FileNotFoundException("Couldn't find yarn.cmd", result); |
| Exceptions.Throw(ex, Logger); |
| throw ex; |
| } |
| return result; |
| } |
| |
| /// <summary> |
| /// Executes `yarn.cmd` with the given parameters. |
| /// </summary> |
| /// <param name="arguments"></param> |
| /// <returns>Whatever was printed to stdout by YARN.</returns> |
| private string Yarn(params string[] arguments) |
| { |
| var startInfo = new ProcessStartInfo |
| { |
| FileName = GetYarnCommandPath(), |
| Arguments = string.Join(" ", arguments), |
| UseShellExecute = false, |
| RedirectStandardOutput = true, |
| RedirectStandardError = false |
| }; |
| var process = Process.Start(startInfo); |
| var output = new StringBuilder(); |
| if (process != null) |
| { |
| process.OutputDataReceived += delegate(object sender, DataReceivedEventArgs e) |
| { |
| if (!string.IsNullOrWhiteSpace(e.Data)) |
| { |
| output.Append(e.Data); |
| } |
| }; |
| process.BeginOutputReadLine(); |
| process.WaitForExit(); |
| |
| if (process.ExitCode != 0) |
| { |
| var ex = new Exception("YARN process exited with non-zero error code."); |
| Exceptions.Throw(ex, Logger); |
| } |
| } |
| else |
| { |
| var ex = new Exception("YARN process didn't start."); |
| Exceptions.Throw(ex, Logger); |
| throw ex; |
| } |
| return output.ToString(); |
| } |
| } |
| } |