Thomas Vachuska | 275d2e8 | 2016-07-14 17:41:34 -0700 | [diff] [blame] | 1 | /* |
Brian O'Connor | a09fe5b | 2017-08-03 21:12:30 -0700 | [diff] [blame] | 2 | * Copyright 2016-present Open Networking Foundation |
Thomas Vachuska | 275d2e8 | 2016-07-14 17:41:34 -0700 | [diff] [blame] | 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package org.onosproject.buckdaemon; |
| 18 | |
| 19 | import com.google.common.io.ByteStreams; |
| 20 | import com.puppycrawl.tools.checkstyle.api.CheckstyleException; |
| 21 | import org.onosproject.checkstyle.CheckstyleRunner; |
| 22 | |
| 23 | import java.io.IOException; |
Ray Milkey | 8df94b8 | 2016-11-16 11:03:32 -0800 | [diff] [blame] | 24 | import java.io.PrintStream; |
Thomas Vachuska | 275d2e8 | 2016-07-14 17:41:34 -0700 | [diff] [blame] | 25 | import java.net.ServerSocket; |
| 26 | import java.net.Socket; |
| 27 | import java.nio.ByteBuffer; |
| 28 | import java.nio.channels.FileChannel; |
| 29 | import java.nio.channels.FileLock; |
| 30 | import java.nio.file.Files; |
| 31 | import java.nio.file.Path; |
| 32 | import java.nio.file.Paths; |
| 33 | import java.util.HashMap; |
| 34 | import java.util.Map; |
| 35 | import java.util.Timer; |
| 36 | import java.util.TimerTask; |
| 37 | import java.util.concurrent.Callable; |
| 38 | import java.util.concurrent.ExecutorService; |
| 39 | import java.util.concurrent.Executors; |
| 40 | |
| 41 | import static java.nio.file.StandardOpenOption.*; |
| 42 | |
| 43 | /** |
| 44 | * Buck daemon process. |
| 45 | */ |
| 46 | public final class BuckDaemon { |
| 47 | |
| 48 | private static long POLLING_INTERVAL = 1000; //ms |
| 49 | |
| 50 | private final Map<String, BuckTask> tasks = new HashMap<>(); |
| 51 | private final String portLock; |
| 52 | private final String buckPid; |
| 53 | |
| 54 | // Public construction forbidden |
| 55 | private BuckDaemon(String[] args) { |
| 56 | portLock = args[0]; |
| 57 | buckPid = args[1]; |
| 58 | } |
| 59 | |
| 60 | /** |
| 61 | * Main entry point for the daemon. |
| 62 | * |
| 63 | * @param args command-line arguments |
| 64 | */ |
| 65 | public static void main(String[] args) |
| 66 | throws CheckstyleException, IOException { |
| 67 | BuckDaemon daemon = new BuckDaemon(args); |
| 68 | daemon.registerTasks(); |
| 69 | daemon.startServer(); |
| 70 | } |
| 71 | |
| 72 | /** |
| 73 | * Registers re-entrant tasks by their task name. |
| 74 | */ |
| 75 | private void registerTasks() { |
| 76 | tasks.put("checkstyle", new CheckstyleRunner(System.getProperty("checkstyle.config"), |
| 77 | System.getProperty("checkstyle.suppressions"))); |
| 78 | // tasks.put("swagger", new SwaggerGenerator()); |
| 79 | } |
| 80 | |
| 81 | /** |
| 82 | * Monitors another PID and exit when that process exits. |
| 83 | */ |
| 84 | private void watchProcess(String pid) { |
| 85 | if (pid == null || pid.equals("0")) { |
| 86 | return; |
| 87 | } |
| 88 | Timer timer = new Timer(true); // start as a daemon, so we don't hang shutdown |
| 89 | timer.scheduleAtFixedRate(new TimerTask() { |
| 90 | private String cmd = "kill -s 0 " + pid; |
| 91 | |
| 92 | @Override |
| 93 | public void run() { |
| 94 | try { |
| 95 | Process p = Runtime.getRuntime().exec(cmd); |
| 96 | p.waitFor(); |
| 97 | if (p.exitValue() != 0) { |
| 98 | System.err.println("shutting down..."); |
| 99 | System.exit(0); |
| 100 | } |
| 101 | } catch (IOException | InterruptedException e) { |
| 102 | //no-op |
| 103 | e.printStackTrace(); |
| 104 | } |
| 105 | } |
| 106 | }, POLLING_INTERVAL, POLLING_INTERVAL); |
| 107 | } |
| 108 | |
| 109 | /** |
| 110 | * Initiates a server. |
| 111 | */ |
| 112 | private void startServer() throws IOException, CheckstyleException { |
| 113 | // Use a file lock to ensure only one copy of the daemon runs |
| 114 | Path portLockPath = Paths.get(portLock); |
| 115 | FileChannel channel = FileChannel.open(portLockPath, WRITE, CREATE); |
| 116 | FileLock lock = channel.tryLock(); |
| 117 | if (lock == null) { |
| 118 | System.out.println("Server is already running"); |
| 119 | System.exit(1); |
| 120 | } //else, hold the lock until the JVM exits |
| 121 | |
| 122 | // Start the server and bind it to a random port |
| 123 | ServerSocket server = new ServerSocket(0); |
| 124 | |
| 125 | // Monitor the parent buck process |
| 126 | watchProcess(buckPid); |
| 127 | |
| 128 | // Set up hook to clean up after ourselves |
| 129 | Runtime.getRuntime().addShutdownHook(new Thread(() -> { |
| 130 | try { |
| 131 | channel.truncate(0); |
| 132 | channel.close(); |
| 133 | System.err.println("tear down..."); |
| 134 | Files.delete(portLockPath); |
| 135 | } catch (IOException e) { |
| 136 | //no-op: shutting down |
| 137 | e.printStackTrace(); |
| 138 | } |
| 139 | })); |
| 140 | |
| 141 | // Write the bound port to the port file |
| 142 | int port = server.getLocalPort(); |
| 143 | channel.truncate(0); |
| 144 | channel.write(ByteBuffer.wrap(Integer.toString(port).getBytes())); |
| 145 | |
| 146 | // Instantiate a Checkstyle runner and executor; serve until exit... |
| 147 | ExecutorService executor = Executors.newCachedThreadPool(); |
| 148 | while (true) { |
| 149 | try { |
| 150 | executor.submit(new BuckTaskRunner(server.accept())); |
| 151 | } catch (Exception e) { |
| 152 | e.printStackTrace(); |
| 153 | //no-op |
| 154 | } |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * Runnable capable of invoking the appropriate Buck task with input |
| 160 | * consumed form the specified socket and output produced back to that |
| 161 | * socket. |
| 162 | */ |
| 163 | private class BuckTaskRunner implements Runnable { |
| 164 | |
| 165 | private final Socket socket; |
| 166 | |
| 167 | public BuckTaskRunner(Socket socket) { |
| 168 | this.socket = socket; |
| 169 | } |
| 170 | |
| 171 | @Override |
| 172 | public void run() { |
| 173 | try { |
| 174 | BuckTaskContext context = new BuckTaskContext(socket.getInputStream()); |
| 175 | String taskName = context.taskName(); |
| 176 | if (!taskName.isEmpty()) { |
| 177 | BuckTask task = tasks.get(taskName); |
| 178 | if (task != null) { |
| 179 | System.out.println(String.format("Executing task '%s'", taskName)); |
Ray Milkey | 8df94b8 | 2016-11-16 11:03:32 -0800 | [diff] [blame] | 180 | try { |
| 181 | task.execute(context); |
| 182 | for (String line : context.output()) { |
| 183 | output(socket, line); |
| 184 | } |
| 185 | // TODO should we catch Exception, RuntimeException, or something specific? |
| 186 | } catch (Throwable e) { |
| 187 | e.printStackTrace(new PrintStream(socket.getOutputStream())); |
Thomas Vachuska | 275d2e8 | 2016-07-14 17:41:34 -0700 | [diff] [blame] | 188 | } |
| 189 | } else { |
| 190 | String message = String.format("No task named '%s'", taskName); |
| 191 | System.out.print(message); |
| 192 | output(socket, message); |
| 193 | } |
| 194 | } |
| 195 | socket.getOutputStream().flush(); |
| 196 | socket.close(); |
| 197 | } catch (IOException e) { |
| 198 | e.printStackTrace(); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | private void output(Socket socket, String line) throws IOException { |
| 203 | socket.getOutputStream().write((line + "\n").getBytes()); |
| 204 | } |
| 205 | } |
| 206 | } |