| /* |
| * Copyright 2016 Open Networking Laboratory |
| * |
| * Licensed 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. |
| */ |
| |
| package org.onlab.warden; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.collect.ImmutableSet; |
| import com.google.common.io.ByteStreams; |
| |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.PrintWriter; |
| import java.text.SimpleDateFormat; |
| import java.util.Date; |
| import java.util.HashSet; |
| import java.util.Random; |
| import java.util.Set; |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import java.util.concurrent.TimeUnit; |
| |
| import static com.google.common.base.Preconditions.*; |
| |
| /** |
| * Warden for tracking use of shared test cells. |
| */ |
| class Warden { |
| |
| private static final String CELL_NOT_NULL = "Cell name cannot be null"; |
| private static final String USER_NOT_NULL = "User name cannot be null"; |
| private static final String KEY_NOT_NULL = "User key cannot be null"; |
| private static final String UTF_8 = "UTF-8"; |
| |
| private static final String AUTHORIZED_KEYS = "authorized_keys"; |
| |
| private static final long TIMEOUT = 10; // 10 seconds |
| private static final int MAX_MINUTES = 240; // 4 hours max |
| private static final int MINUTE = 60_000; // 1 minute |
| private static final int DEFAULT_MINUTES = 60; |
| |
| private final File log = new File("warden.log"); |
| |
| private final File cells = new File("cells"); |
| private final File supported = new File(cells, "supported"); |
| private final File reserved = new File(cells, "reserved"); |
| |
| private final Random random = new Random(); |
| |
| private final Timer timer = new Timer("cell-pruner", true); |
| |
| /** |
| * Creates a new cell warden. |
| */ |
| Warden() { |
| random.setSeed(System.currentTimeMillis()); |
| timer.schedule(new Reposessor(), MINUTE / 4, MINUTE / 2); |
| } |
| |
| /** |
| * Returns list of names of supported cells. |
| * |
| * @return list of cell names |
| */ |
| Set<String> getCells() { |
| String[] list = supported.list(); |
| return list != null ? ImmutableSet.copyOf(list) : ImmutableSet.of(); |
| } |
| |
| /** |
| * Returns list of names of available cells. |
| * |
| * @return list of cell names |
| */ |
| Set<String> getAvailableCells() { |
| Set<String> available = new HashSet<>(getCells()); |
| available.removeAll(getReservedCells()); |
| return ImmutableSet.copyOf(available); |
| } |
| |
| /** |
| * Returns list of names of reserved cells. |
| * |
| * @return list of cell names |
| */ |
| Set<String> getReservedCells() { |
| String[] list = reserved.list(); |
| return list != null ? ImmutableSet.copyOf(list) : ImmutableSet.of(); |
| } |
| |
| /** |
| * Returns reservation for the specified user. |
| * |
| * @param userName user name |
| * @return cell reservation record or null if user does not have one |
| */ |
| Reservation currentUserReservation(String userName) { |
| checkNotNull(userName, USER_NOT_NULL); |
| for (String cellName : getReservedCells()) { |
| Reservation reservation = currentCellReservation(cellName); |
| if (reservation != null && userName.equals(reservation.userName)) { |
| return reservation; |
| } |
| } |
| return null; |
| } |
| |
| /** |
| * Returns the name of the user who reserved the given cell. |
| * |
| * @param cellName cell name |
| * @return cell reservation record or null if cell is not reserved |
| */ |
| Reservation currentCellReservation(String cellName) { |
| checkNotNull(cellName, CELL_NOT_NULL); |
| File cellFile = new File(reserved, cellName); |
| if (!cellFile.exists()) { |
| return null; |
| } |
| try (InputStream stream = new FileInputStream(cellFile)) { |
| return new Reservation(new String(ByteStreams.toByteArray(stream), "UTF-8")); |
| } catch (IOException e) { |
| throw new IllegalStateException("Unable to get current user for cell " + cellName, e); |
| } |
| } |
| |
| /** |
| * Reserves a cell for the specified user and their public access key. |
| * |
| * @param userName user name |
| * @param sshKey user ssh public key |
| * @param minutes number of minutes for reservation |
| * @return reserved cell definition |
| */ |
| synchronized String borrowCell(String userName, String sshKey, int minutes) { |
| checkNotNull(userName, USER_NOT_NULL); |
| checkNotNull(sshKey, KEY_NOT_NULL); |
| checkArgument(minutes < MAX_MINUTES, "Number of minutes must be less than %d", MAX_MINUTES); |
| long now = System.currentTimeMillis(); |
| Reservation reservation = currentUserReservation(userName); |
| if (reservation == null) { |
| checkArgument(minutes >= 0, "Number of minutes must be non-negative"); |
| Set<String> cells = getAvailableCells(); |
| checkState(!cells.isEmpty(), "No cells are presently available"); |
| String cellName = ImmutableList.copyOf(cells).get(random.nextInt(cells.size())); |
| reservation = new Reservation(cellName, userName, now, minutes == 0 ? DEFAULT_MINUTES : minutes); |
| } else if (minutes == 0) { |
| // If minutes are 0, simply return the cell definition |
| return getCellDefinition(reservation.cellName); |
| } else { |
| reservation = new Reservation(reservation.cellName, userName, now, minutes); |
| } |
| |
| reserveCell(reservation); |
| createCell(reservation, sshKey); |
| log(userName, reservation.cellName, "borrowed for " + reservation.duration + " minutes"); |
| return getCellDefinition(reservation.cellName); |
| } |
| |
| /** |
| * Returns the specified cell for the specified user and their public access key. |
| * |
| * @param userName user name |
| */ |
| synchronized void returnCell(String userName) { |
| checkNotNull(userName, USER_NOT_NULL); |
| Reservation reservation = currentUserReservation(userName); |
| checkState(reservation != null, "User %s has no cell reservations", userName); |
| |
| unreserveCell(reservation); |
| destroyCell(reservation); |
| log(userName, reservation.cellName, "returned"); |
| } |
| |
| /** |
| * Reserves the specified cell for the user the source file and writes the |
| * specified content to the target file. |
| * |
| * @param reservation cell reservation record |
| */ |
| private void reserveCell(Reservation reservation) { |
| File cellFile = new File(reserved, reservation.cellName); |
| try (FileOutputStream stream = new FileOutputStream(cellFile)) { |
| stream.write(reservation.encode().getBytes(UTF_8)); |
| } catch (IOException e) { |
| throw new IllegalStateException("Unable to reserve cell " + reservation.cellName, e); |
| } |
| } |
| |
| private String getCellDefinition(String cellName) { |
| return exec("bin/cell-def " + cellName); |
| } |
| |
| /** |
| * Cancels the specified reservation. |
| * |
| * @param reservation reservation record |
| */ |
| private void unreserveCell(Reservation reservation) { |
| checkState(new File(reserved, reservation.cellName).delete(), |
| "Unable to return cell %s", reservation.cellName); |
| } |
| |
| /** |
| * Creates the cell for the specified user SSH key. |
| * |
| * @param reservation cell reservation |
| * @param sshKey ssh key |
| */ |
| private void createCell(Reservation reservation, String sshKey) { |
| String cellInfo = getCellInfo(reservation.cellName); |
| String cmd = String.format("bin/create-cell %s %s %s", |
| reservation.cellName, cellInfo, sshKey); |
| exec(cmd); |
| } |
| |
| /** |
| * Destroys the specified cell. |
| * |
| * @param reservation reservation record |
| */ |
| private void destroyCell(Reservation reservation) { |
| exec("bin/destroy-cell " + reservation.cellName); |
| } |
| |
| /** |
| * Reads the definition of the specified cell. |
| * |
| * @param cellName cell name |
| * @return cell definition |
| */ |
| String getCellInfo(String cellName) { |
| File cellFile = new File(supported, cellName); |
| try (InputStream stream = new FileInputStream(cellFile)) { |
| return new String(ByteStreams.toByteArray(stream), UTF_8); |
| } catch (IOException e) { |
| throw new IllegalStateException("Unable to definition for cell " + cellName, e); |
| } |
| } |
| |
| // Executes the specified command. |
| private String exec(String command) { |
| try { |
| Process process = Runtime.getRuntime().exec(command); |
| String output = new String(ByteStreams.toByteArray(process.getInputStream()), UTF_8); |
| process.waitFor(TIMEOUT, TimeUnit.SECONDS); |
| return process.exitValue() == 0 ? output : null; |
| } catch (Exception e) { |
| throw new IllegalStateException("Unable to execute " + command); |
| } |
| } |
| |
| // Creates an audit log entry. |
| void log(String userName, String cellName, String action) { |
| try (FileOutputStream fos = new FileOutputStream(log, true); |
| PrintWriter pw = new PrintWriter(fos)) { |
| SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); |
| pw.println(String.format("%s\t%s\t%s\t%s", format.format(new Date()), |
| userName, cellName, action)); |
| pw.flush(); |
| } catch (IOException e) { |
| throw new IllegalStateException("Unable to log reservation action", e); |
| } |
| } |
| |
| // Task for re-possessing overdue cells |
| private class Reposessor extends TimerTask { |
| @Override |
| public void run() { |
| long now = System.currentTimeMillis(); |
| for (String cellName : getReservedCells()) { |
| Reservation reservation = currentCellReservation(cellName); |
| if (reservation != null && |
| (reservation.time + reservation.duration * MINUTE) < now) { |
| try { |
| returnCell(reservation.userName); |
| } catch (Exception e) { |
| e.printStackTrace(); |
| } |
| } |
| } |
| } |
| } |
| } |