Thomas Vachuska | 1eff3a6 | 2016-05-03 01:07:24 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016 Open Networking Laboratory |
| 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.onlab.warden; |
| 18 | |
| 19 | import com.google.common.collect.ImmutableList; |
| 20 | import com.google.common.collect.ImmutableSet; |
| 21 | import com.google.common.io.ByteStreams; |
| 22 | |
| 23 | import java.io.File; |
| 24 | import java.io.FileInputStream; |
| 25 | import java.io.FileOutputStream; |
| 26 | import java.io.IOException; |
| 27 | import java.io.InputStream; |
| 28 | import java.io.PrintWriter; |
| 29 | import java.text.SimpleDateFormat; |
| 30 | import java.util.Date; |
| 31 | import java.util.HashSet; |
| 32 | import java.util.List; |
| 33 | import java.util.Random; |
| 34 | import java.util.Set; |
| 35 | import java.util.Timer; |
| 36 | import java.util.TimerTask; |
| 37 | import java.util.concurrent.TimeUnit; |
| 38 | import java.util.regex.Matcher; |
| 39 | import java.util.regex.Pattern; |
| 40 | |
| 41 | import static com.google.common.base.Preconditions.*; |
| 42 | |
| 43 | /** |
| 44 | * Warden for tracking use of shared test cells. |
| 45 | */ |
| 46 | class Warden { |
| 47 | |
| 48 | private static final String CELL_NOT_NULL = "Cell name cannot be null"; |
| 49 | private static final String USER_NOT_NULL = "User name cannot be null"; |
| 50 | private static final String KEY_NOT_NULL = "User key cannot be null"; |
| 51 | private static final String UTF_8 = "UTF-8"; |
| 52 | private static final long TIMEOUT = 3; |
| 53 | |
| 54 | private static final String AUTHORIZED_KEYS = "authorized_keys"; |
| 55 | |
| 56 | private static final int MAX_MINUTES = 240; // 4 hours max |
| 57 | private static final int MINUTE = 60_000; // 1 minute |
| 58 | |
| 59 | private final File log = new File("warden.log"); |
| 60 | |
| 61 | private final File cells = new File("cells"); |
| 62 | private final File supported = new File(cells, "supported"); |
| 63 | private final File reserved = new File(cells, "reserved"); |
| 64 | |
| 65 | private final Random random = new Random(); |
| 66 | |
| 67 | private final Timer timer = new Timer("cell-pruner", true); |
| 68 | |
| 69 | /** |
| 70 | * Creates a new cell warden. |
| 71 | */ |
| 72 | Warden() { |
| 73 | random.setSeed(System.currentTimeMillis()); |
Thomas Vachuska | 71ff332 | 2016-05-03 15:33:05 -0700 | [diff] [blame] | 74 | timer.schedule(new Reposessor(), MINUTE / 4, MINUTE / 2); |
Thomas Vachuska | 1eff3a6 | 2016-05-03 01:07:24 -0700 | [diff] [blame] | 75 | } |
| 76 | |
| 77 | /** |
| 78 | * Returns list of names of supported cells. |
| 79 | * |
| 80 | * @return list of cell names |
| 81 | */ |
| 82 | Set<String> getCells() { |
| 83 | String[] list = supported.list(); |
| 84 | return list != null ? ImmutableSet.copyOf(list) : ImmutableSet.of(); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * Returns list of names of available cells. |
| 89 | * |
| 90 | * @return list of cell names |
| 91 | */ |
| 92 | Set<String> getAvailableCells() { |
| 93 | Set<String> available = new HashSet<>(getCells()); |
| 94 | available.removeAll(getReservedCells()); |
| 95 | return ImmutableSet.copyOf(available); |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Returns list of names of reserved cells. |
| 100 | * |
| 101 | * @return list of cell names |
| 102 | */ |
| 103 | Set<String> getReservedCells() { |
| 104 | String[] list = reserved.list(); |
| 105 | return list != null ? ImmutableSet.copyOf(list) : ImmutableSet.of(); |
| 106 | } |
| 107 | |
| 108 | |
| 109 | /** |
| 110 | * Returns reservation for the specified user. |
| 111 | * |
| 112 | * @param userName user name |
| 113 | * @return cell reservation record or null if user does not have one |
| 114 | */ |
| 115 | Reservation currentUserReservation(String userName) { |
| 116 | checkNotNull(userName, USER_NOT_NULL); |
| 117 | for (String cellName : getReservedCells()) { |
| 118 | Reservation reservation = currentCellReservation(cellName); |
| 119 | if (reservation != null && userName.equals(reservation.userName)) { |
| 120 | return reservation; |
| 121 | } |
| 122 | } |
| 123 | return null; |
| 124 | } |
| 125 | |
| 126 | /** |
| 127 | * Returns the name of the user who reserved the given cell. |
| 128 | * |
| 129 | * @param cellName cell name |
| 130 | * @return cell reservation record or null if cell is not reserved |
| 131 | */ |
| 132 | Reservation currentCellReservation(String cellName) { |
| 133 | checkNotNull(cellName, CELL_NOT_NULL); |
| 134 | File cellFile = new File(reserved, cellName); |
| 135 | if (!cellFile.exists()) { |
| 136 | return null; |
| 137 | } |
| 138 | try (InputStream stream = new FileInputStream(cellFile)) { |
| 139 | return new Reservation(new String(ByteStreams.toByteArray(stream), "UTF-8")); |
| 140 | } catch (IOException e) { |
| 141 | throw new IllegalStateException("Unable to get current user for cell " + cellName, e); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Reserves a cell for the specified user and their public access key. |
| 147 | * |
| 148 | * @param userName user name |
| 149 | * @param sshKey user ssh public key |
| 150 | * @param minutes number of minutes for reservation |
| 151 | * @return reserved cell definition |
| 152 | */ |
| 153 | synchronized String borrowCell(String userName, String sshKey, int minutes) { |
| 154 | checkNotNull(userName, USER_NOT_NULL); |
| 155 | checkNotNull(sshKey, KEY_NOT_NULL); |
| 156 | checkArgument(minutes > 0, "Number of minutes must be positive"); |
| 157 | checkArgument(minutes < MAX_MINUTES, "Number of minutes must be less than %d", MAX_MINUTES); |
| 158 | long now = System.currentTimeMillis(); |
| 159 | Reservation reservation = currentUserReservation(userName); |
| 160 | if (reservation == null) { |
| 161 | Set<String> cells = getAvailableCells(); |
| 162 | checkState(!cells.isEmpty(), "No cells are presently available"); |
| 163 | String cellName = ImmutableList.copyOf(cells).get(random.nextInt(cells.size())); |
| 164 | reservation = new Reservation(cellName, userName, now, minutes); |
| 165 | } else { |
| 166 | reservation = new Reservation(reservation.cellName, userName, now, minutes); |
| 167 | } |
| 168 | |
| 169 | reserveCell(reservation.cellName, reservation); |
| 170 | installUserKeys(reservation.cellName, userName, sshKey); |
| 171 | log(userName, reservation.cellName, "borrowed for " + minutes + " minutes"); |
| 172 | return getCellDefinition(reservation.cellName); |
| 173 | } |
| 174 | |
| 175 | /** |
| 176 | * Reserves the specified cell for the user the source file and writes the |
| 177 | * specified content to the target file. |
| 178 | * |
| 179 | * @param cellName cell name |
| 180 | * @param reservation cell reservation record |
| 181 | */ |
| 182 | private void reserveCell(String cellName, Reservation reservation) { |
| 183 | try (FileOutputStream stream = new FileOutputStream(new File(reserved, cellName))) { |
| 184 | stream.write(reservation.encode().getBytes(UTF_8)); |
| 185 | } catch (IOException e) { |
| 186 | throw new IllegalStateException("Unable to reserve cell " + cellName, e); |
| 187 | } |
| 188 | } |
| 189 | |
| 190 | /** |
| 191 | * Returns the specified cell for the specified user and their public access key. |
| 192 | * |
| 193 | * @param userName user name |
| 194 | */ |
| 195 | synchronized void returnCell(String userName) { |
| 196 | checkNotNull(userName, USER_NOT_NULL); |
| 197 | Reservation reservation = currentUserReservation(userName); |
| 198 | checkState(reservation != null, "User %s has no cell reservations", userName); |
| 199 | checkState(new File(reserved, reservation.cellName).delete(), |
| 200 | "Unable to return cell %s", reservation.cellName); |
| 201 | uninstallUserKeys(reservation.cellName); |
| 202 | log(userName, reservation.cellName, "returned"); |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * Reads the definition of the specified cell. |
| 207 | * |
| 208 | * @param cellName cell name |
| 209 | * @return cell definition |
| 210 | */ |
| 211 | String getCellDefinition(String cellName) { |
| 212 | File cellFile = new File(supported, cellName); |
| 213 | try (InputStream stream = new FileInputStream(cellFile)) { |
| 214 | return new String(ByteStreams.toByteArray(stream), UTF_8); |
| 215 | } catch (IOException e) { |
| 216 | throw new IllegalStateException("Unable to definition for cell " + cellName, e); |
| 217 | } |
| 218 | } |
| 219 | |
| 220 | // Returns list of cell hosts, i.e. OC#, OCN |
| 221 | private List<String> cellHosts(String cellName) { |
| 222 | ImmutableList.Builder<String> builder = ImmutableList.builder(); |
| 223 | Pattern pattern = Pattern.compile("export OC[0-9N]=(.*)"); |
| 224 | for (String line : getCellDefinition(cellName).split("\n")) { |
| 225 | Matcher matcher = pattern.matcher(line); |
| 226 | if (matcher.matches()) { |
| 227 | builder.add(matcher.group(1).replaceAll("[\"']", "")); |
| 228 | } |
| 229 | } |
| 230 | return builder.build(); |
| 231 | } |
| 232 | |
| 233 | // Installs the specified user's key on all hosts of the given cell. |
| 234 | private void installUserKeys(String cellName, String userName, String sshKey) { |
| 235 | File authKeysFile = authKeys(sshKey); |
| 236 | for (String host : cellHosts(cellName)) { |
| 237 | installAuthorizedKey(host, authKeysFile.getPath()); |
| 238 | } |
| 239 | checkState(authKeysFile.delete(), "Unable to install user keys"); |
| 240 | } |
| 241 | |
| 242 | // Uninstalls the user keys on the specified cell |
| 243 | private void uninstallUserKeys(String cellName) { |
| 244 | for (String host : cellHosts(cellName)) { |
| 245 | installAuthorizedKey(host, AUTHORIZED_KEYS); |
| 246 | } |
| 247 | } |
| 248 | |
| 249 | // Installs the authorized keys on the specified host. |
| 250 | private void installAuthorizedKey(String host, String authorizedKeysFile) { |
| 251 | String cmd = "scp " + authorizedKeysFile + " sdn@" + host + ":.ssh/authorized_keys"; |
| 252 | try { |
| 253 | Process process = Runtime.getRuntime().exec(cmd); |
| 254 | process.waitFor(TIMEOUT, TimeUnit.SECONDS); |
| 255 | } catch (Exception e) { |
| 256 | throw new IllegalStateException("Unable to set authorized keys for host " + host); |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | // Returns the file containing authorized keys that incudes the specified key. |
| 261 | private File authKeys(String sshKey) { |
| 262 | File keysFile = new File(AUTHORIZED_KEYS); |
| 263 | try { |
| 264 | File tmp = File.createTempFile("warden-", ".auth"); |
| 265 | tmp.deleteOnExit(); |
| 266 | try (InputStream stream = new FileInputStream(keysFile); |
| 267 | PrintWriter output = new PrintWriter(tmp)) { |
| 268 | String baseKeys = new String(ByteStreams.toByteArray(stream), UTF_8); |
| 269 | output.println(baseKeys); |
| 270 | output.println(sshKey); |
| 271 | return tmp; |
| 272 | } catch (IOException e) { |
| 273 | throw new IllegalStateException("Unable to generate authorized keys", e); |
| 274 | } |
| 275 | } catch (IOException e) { |
| 276 | throw new IllegalStateException("Unable to generate authorized keys", e); |
| 277 | } |
| 278 | } |
| 279 | |
| 280 | // Creates an audit log entry. |
| 281 | void log(String userName, String cellName, String action) { |
| 282 | try (FileOutputStream fos = new FileOutputStream(log, true); |
| 283 | PrintWriter pw = new PrintWriter(fos)) { |
| 284 | SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); |
| 285 | pw.println(String.format("%s\t%s\t%s\t%s", format.format(new Date()), |
| 286 | userName, cellName, action)); |
| 287 | pw.flush(); |
| 288 | } catch (IOException e) { |
| 289 | throw new IllegalStateException("Unable to log reservation action", e); |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | // Task for re-possessing overdue cells |
| 294 | private class Reposessor extends TimerTask { |
| 295 | @Override |
| 296 | public void run() { |
| 297 | long now = System.currentTimeMillis(); |
| 298 | for (String cellName : getReservedCells()) { |
| 299 | Reservation reservation = currentCellReservation(cellName); |
| 300 | if (reservation != null && |
| 301 | (reservation.time + reservation.duration * MINUTE) < now) { |
| 302 | try { |
| 303 | returnCell(reservation.userName); |
| 304 | } catch (Exception e) { |
| 305 | e.printStackTrace(); |
| 306 | } |
| 307 | } |
| 308 | } |
| 309 | } |
| 310 | } |
| 311 | } |