java/src/main/com/google/apphosting/utils/config/AppEngineWebXmlProcessor.java

   1 // Copyright 2008 Google Inc. All Rights Reserved.
   2 package com.google.apphosting.utils.config;
   3
   4 import com.google.apphosting.utils.config.AppEngineWebXml.AdminConsolePage;
   5 import com.google.apphosting.utils.config.AppEngineWebXml.ApiConfig;
   6 import com.google.apphosting.utils.config.AppEngineWebXml.AutomaticScaling;
   7 import com.google.apphosting.utils.config.AppEngineWebXml.BasicScaling;
   8 import com.google.apphosting.utils.config.AppEngineWebXml.ClassLoaderConfig;
   9 import com.google.apphosting.utils.config.AppEngineWebXml.ErrorHandler;
  10 import com.google.apphosting.utils.config.AppEngineWebXml.ManualScaling;
  11 import com.google.apphosting.utils.config.AppEngineWebXml.Pagespeed;
  12 import com.google.apphosting.utils.config.AppEngineWebXml.PrioritySpecifierEntry;
  13
  14 import org.mortbay.xml.XmlParser;
  15 import org.mortbay.xml.XmlParser.Node;
  16 import org.xml.sax.SAXException;
  17
  18 import java.io.IOException;
  19 import java.io.InputStream;
  20 import java.util.Iterator;
  21 import java.util.Map;
  22 import java.util.logging.Level;
  23 import java.util.logging.Logger;
  24
  25 /**
  26  * Constructs an {@link AppEngineWebXml} from an xml document corresponding to
  27  * appengine-web.xsd.  We use Jetty's {@link XmlParser} utility for
  28  * convenience.
  29  *
  30  * @TODO(user): Add a real link to the xsd once it exists and do schema
  31  * validation.
  32  *
  33  */
  34 class AppEngineWebXmlProcessor {
  35
  36   enum FileType { STATIC, RESOURCE }
  37
  38   private static final Logger logger = Logger.getLogger(AppEngineWebXmlProcessor.class.getName());
  39
  40   /**
  41    * Construct an {@link AppEngineWebXml} from the xml document
  42    * identified by the provided {@link InputStream}.
  43    *
  44    * @param is The InputStream containing the xml we want to parse and process.
  45    *
  46    * @return Object representation of the xml document.
  47    * @throws AppEngineConfigException If the input stream cannot be parsed.
  48    */
  49   public AppEngineWebXml processXml(InputStream is) {
  50     XmlParser.Node config = getTopLevelNode(is);
  51     AppEngineWebXml appEngineWebXml = new AppEngineWebXml();
  52     appEngineWebXml.setWarmupRequestsEnabled(true);
  53     for (Object o : config) {
  54       if (!(o instanceof XmlParser.Node)) {
  55         continue;
  56       }
  57       XmlParser.Node node = (XmlParser.Node) o;
  58       processSecondLevelNode(node, appEngineWebXml);
  59     }
  60     checkScalingConstraints(appEngineWebXml);
  61     return appEngineWebXml;
  62   }
  63
  64   /**
  65    * Given an AppEngineWebXml, ensure it has no more than one of the scaling options available.
  66    *
  67    * @throws AppEngineConfigException If there is more than one scaling option selected.
  68    */
  69   private static void checkScalingConstraints(AppEngineWebXml appEngineWebXml) {
  70     int count = appEngineWebXml.getManualScaling().isEmpty() ? 0 : 1;
  71     count += appEngineWebXml.getBasicScaling().isEmpty() ? 0 : 1;
  72     count += appEngineWebXml.getAutomaticScaling().isEmpty() ? 0 : 1;
  73     if (count > 1) {
  74       throw new AppEngineConfigException(
  75           "There may be only one of 'automatic-scaling', 'manual-scaling' or " +
  76           "'basic-scaling' elements.");
  77     }
  78   }
  79
  80   /**
  81    * Given an InputStream, create a Node corresponding to the top level xml
  82    * element.
  83    *
  84    * @throws AppEngineConfigException If the input stream cannot be parsed.
  85    */
  86   XmlParser.Node getTopLevelNode(InputStream is) {
  87     XmlParser xmlParser = new XmlParser();
  88     try {
  89       return xmlParser.parse(is);
  90     } catch (IOException e) {
  91       String msg = "Received IOException parsing the input stream.";
  92       logger.log(Level.SEVERE, msg, e);
  93       throw new AppEngineConfigException(msg, e);
  94     } catch (SAXException e) {
  95       String msg = "Received SAXException parsing the input stream.";
  96       logger.log(Level.SEVERE, msg, e);
  97       throw new AppEngineConfigException(msg, e);
  98     }
  99   }
 100
 101   private void processSecondLevelNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 102     String elementName = node.getTag();
 103     if (elementName.equals("system-properties")) {
 104       processSystemPropertiesNode(node, appEngineWebXml);
 105     } else if (elementName.equals("vm-settings")) {
 106       processVmSettingsNode(node, appEngineWebXml);
 107     } else if (elementName.equals("env-variables")) {
 108       processEnvironmentVariablesNode(node, appEngineWebXml);
 109     } else if (elementName.equals("application")) {
 110       processApplicationNode(node, appEngineWebXml);
 111     } else if (elementName.equals("version")) {
 112       processVersionNode(node, appEngineWebXml);
 113     } else if (elementName.equals("source-language")) {
 114       processSourceLanguageNode(node, appEngineWebXml);
 115     } else if (elementName.equals("module")) {
 116       processModuleNode(node, appEngineWebXml);
 117     } else if (elementName.equals("instance-class")) {
 118       processInstanceClassNode(node, appEngineWebXml);
 119     } else if (elementName.equals("automatic-scaling")) {
 120       processAutomaticScalingNode(node, appEngineWebXml);
 121     } else if (elementName.equals("manual-scaling")) {
 122       processManualScalingNode(node, appEngineWebXml);
 123     } else if (elementName.equals("basic-scaling")) {
 124       processBasicScalingNode(node, appEngineWebXml);
 125     } else if (elementName.equals("static-files")) {
 126       processFilesetNode(node, appEngineWebXml, FileType.STATIC);
 127     } else if (elementName.equals("resource-files")) {
 128       processFilesetNode(node, appEngineWebXml, FileType.RESOURCE);
 129     } else if (elementName.equals("ssl-enabled")) {
 130       processSslEnabledNode(node, appEngineWebXml);
 131     } else if (elementName.equals("sessions-enabled")) {
 132       processSessionsEnabledNode(node, appEngineWebXml);
 133     } else if (elementName.equals("async-session-persistence")) {
 134       processAsyncSessionPersistenceNode(node, appEngineWebXml);
 135     } else if (elementName.equals("user-permissions")) {
 136       processPermissionsNode(node, appEngineWebXml);
 137     } else if (elementName.equals("public-root")) {
 138       processPublicRootNode(node, appEngineWebXml);
 139     } else if (elementName.equals("inbound-services")) {
 140       processInboundServicesNode(node, appEngineWebXml);
 141     } else if (elementName.equals("precompilation-enabled")) {
 142       processPrecompilationEnabledNode(node, appEngineWebXml);
 143     } else if (elementName.equals("admin-console")) {
 144       processAdminConsoleNode(node, appEngineWebXml);
 145     } else if (elementName.equals("static-error-handlers")) {
 146       processErrorHandlerNode(node, appEngineWebXml);
 147     } else if (elementName.equals("warmup-requests-enabled")) {
 148       processWarmupRequestsEnabledNode(node, appEngineWebXml);
 149     } else if (elementName.equals("threadsafe")) {
 150       processThreadsafeNode(node, appEngineWebXml);
 151     } else if (elementName.equals("auto-id-policy")) {
 152       processAutoIdPolicyNode(node, appEngineWebXml);
 153     } else if (elementName.equals("code-lock")) {
 154       processCodeLockNode(node, appEngineWebXml);
 155     } else if (elementName.equals("vm")) {
 156       processVmNode(node, appEngineWebXml);
 157     } else if (elementName.equals("api-config")) {
 158       processApiConfigNode(node, appEngineWebXml);
 159     } else if (elementName.equals("pagespeed")) {
 160       processPagespeedNode(node, appEngineWebXml);
 161     } else if (elementName.equals("class-loader-config")) {
 162       processClassLoaderConfig(node, appEngineWebXml);
 163     } else if (elementName.equals("url-stream-handler")) {
 164       processUrlStreamHandler(node, appEngineWebXml);
 165     } else if (elementName.equals("use-google-connector-j")) {
 166       processUseGoogleConnectorJNode(node, appEngineWebXml);
 167     } else {
 168       throw new AppEngineConfigException("Unrecognized element <" + elementName + ">");
 169     }
 170   }
 171
 172   private void processApplicationNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 173     appEngineWebXml.setAppId(getTextNode(node));
 174   }
 175
 176   private void processPublicRootNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 177     appEngineWebXml.setPublicRoot(getTextNode(node));
 178   }
 179
 180   private void processVersionNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 181     appEngineWebXml.setMajorVersionId(getTextNode(node));
 182   }
 183
 184   private void processSourceLanguageNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 185     appEngineWebXml.setSourceLanguage(getTextNode(node));
 186   }
 187
 188   private void processModuleNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 189     appEngineWebXml.setModule(getTextNode(node));
 190   }
 191
 192   private void processInstanceClassNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 193     appEngineWebXml.setInstanceClass(getTextNode(node));
 194   }
 195
 196   private String getChildNodeText(XmlParser.Node parentNode, String childTag) {
 197     String result = null;
 198     XmlParser.Node node = parentNode.get(childTag);
 199     if (node != null) {
 200       result = (String) node.get(0);
 201     }
 202     return result;
 203   }
 204
 205   private void processAutomaticScalingNode(XmlParser.Node settingsNode,
 206       AppEngineWebXml appEngineWebXml) {
 207     AutomaticScaling automaticScaling = appEngineWebXml.getAutomaticScaling();
 208     automaticScaling.setMinPendingLatency(getChildNodeText(settingsNode, "min-pending-latency"));
 209     automaticScaling.setMaxPendingLatency(getChildNodeText(settingsNode, "max-pending-latency"));
 210     automaticScaling.setMinIdleInstances(getChildNodeText(settingsNode, "min-idle-instances"));
 211     automaticScaling.setMaxIdleInstances(getChildNodeText(settingsNode, "max-idle-instances"));
 212     automaticScaling.setMaxConcurrentRequests(getChildNodeText(settingsNode,
 213         "max-concurrent-requests"));
 214   }
 215
 216   private void processManualScalingNode(XmlParser.Node settingsNode,
 217       AppEngineWebXml appEngineWebXml) {
 218     ManualScaling manualScaling = appEngineWebXml.getManualScaling();
 219     manualScaling.setInstances(getChildNodeText(settingsNode, "instances"));
 220   }
 221
 222   private void processBasicScalingNode(XmlParser.Node settingsNode,
 223       AppEngineWebXml appEngineWebXml) {
 224     BasicScaling basicScaling = appEngineWebXml.getBasicScaling();
 225     basicScaling.setMaxInstances(getChildNodeText(settingsNode, "max-instances"));
 226     basicScaling.setIdleTimeout(getChildNodeText(settingsNode, "idle-timeout"));
 227   }
 228
 229   private void processSslEnabledNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 230     appEngineWebXml.setSslEnabled(getBooleanValue(node));
 231   }
 232
 233   private void processSessionsEnabledNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 234     appEngineWebXml.setSessionsEnabled(getBooleanValue(node));
 235   }
 236
 237   private void processAsyncSessionPersistenceNode(
 238       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 239     boolean enabled = getBooleanAttributeValue(node, "enabled");
 240     appEngineWebXml.setAsyncSessionPersistence(enabled);
 241     String queueName = trim(node.getAttribute("queue-name"));
 242     appEngineWebXml.setAsyncSessionPersistenceQueueName(queueName);
 243   }
 244
 245   private void processPrecompilationEnabledNode(XmlParser.Node node,
 246                                                 AppEngineWebXml appEngineWebXml) {
 247     appEngineWebXml.setPrecompilationEnabled(getBooleanValue(node));
 248   }
 249
 250   private void processWarmupRequestsEnabledNode(XmlParser.Node node,
 251                                                 AppEngineWebXml appEngineWebXml) {
 252     appEngineWebXml.setWarmupRequestsEnabled(getBooleanValue(node));
 253   }
 254
 255   private void processThreadsafeNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 256     appEngineWebXml.setThreadsafe(getBooleanValue(node));
 257   }
 258
 259   private void processAutoIdPolicyNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 260     appEngineWebXml.setAutoIdPolicy(getTextNode(node));
 261   }
 262
 263   private void processCodeLockNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 264     appEngineWebXml.setCodeLock(getBooleanValue(node));
 265   }
 266
 267   private void processVmNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 268     appEngineWebXml.setUseVm(getBooleanValue(node));
 269   }
 270
 271   private void processFilesetNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml,
 272       FileType type) {
 273     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "include");
 274     while (nodeIter.hasNext()) {
 275       XmlParser.Node includeNode = nodeIter.next();
 276       String path = trim(includeNode.getAttribute("path"));
 277       if (type == FileType.STATIC) {
 278         String expiration = trim(includeNode.getAttribute("expiration"));
 279         AppEngineWebXml.StaticFileInclude staticFileInclude =
 280             appEngineWebXml.includeStaticPattern(path, expiration);
 281
 282         Map<String, String> httpHeaders = staticFileInclude.getHttpHeaders();
 283         Iterator<XmlParser.Node> httpHeaderIter = getNodeIterator(includeNode, "http-header");
 284         while (httpHeaderIter.hasNext()) {
 285           XmlParser.Node httpHeaderNode = httpHeaderIter.next();
 286           String name = httpHeaderNode.getAttribute("name");
 287           String value = httpHeaderNode.getAttribute("value");
 288
 289           if (httpHeaders.containsKey(name)) {
 290             throw new AppEngineConfigException("Two http-header elements have the same name.");
 291           }
 292
 293           httpHeaders.put(name, value);
 294         }
 295       } else {
 296         appEngineWebXml.includeResourcePattern(path);
 297       }
 298     }
 299
 300     nodeIter = getNodeIterator(node, "exclude");
 301     while (nodeIter.hasNext()) {
 302       XmlParser.Node subNode = nodeIter.next();
 303       String path = trim(subNode.getAttribute("path"));
 304       if (type == FileType.STATIC) {
 305         appEngineWebXml.excludeStaticPattern(path);
 306       } else {
 307         appEngineWebXml.excludeResourcePattern(path);
 308       }
 309     }
 310   }
 311
 312   private Iterator<XmlParser.Node> getNodeIterator(XmlParser.Node node, String filter) {
 313     @SuppressWarnings("unchecked")
 314     Iterator<XmlParser.Node> iterator = node.iterator(filter);
 315     return iterator;
 316   }
 317
 318   private void processSystemPropertiesNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 319     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "property");
 320     while (nodeIter.hasNext()) {
 321       XmlParser.Node subNode = nodeIter.next();
 322       String propertyName = trim(subNode.getAttribute("name"));
 323       String propertyValue = trim(subNode.getAttribute("value"));
 324       appEngineWebXml.addSystemProperty(propertyName, propertyValue);
 325     }
 326   }
 327
 328   private void processVmSettingsNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 329     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "setting");
 330     while (nodeIter.hasNext()) {
 331       XmlParser.Node subNode = nodeIter.next();
 332       String name = trim(subNode.getAttribute("name"));
 333       String value = trim(subNode.getAttribute("value"));
 334       appEngineWebXml.addVmSetting(name, value);
 335     }
 336   }
 337
 338   private void processEnvironmentVariablesNode(
 339       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 340     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "env-var");
 341     while (nodeIter.hasNext()) {
 342       XmlParser.Node subNode = nodeIter.next();
 343       String propertyName = trim(subNode.getAttribute("name"));
 344       String propertyValue = trim(subNode.getAttribute("value"));
 345       appEngineWebXml.addEnvironmentVariable(propertyName, propertyValue);
 346     }
 347   }
 348
 349   private void processPermissionsNode(
 350       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 351     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "permission");
 352     while (nodeIter.hasNext()) {
 353       XmlParser.Node subNode = nodeIter.next();
 354       String className = trim(subNode.getAttribute("class"));
 355       String name = trim(subNode.getAttribute("name"));
 356       String actions = trim(subNode.getAttribute("actions"));
 357       appEngineWebXml.addUserPermission(className, name, actions);
 358     }
 359   }
 360
 361   private void processInboundServicesNode(
 362       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 363     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "service");
 364     while (nodeIter.hasNext()) {
 365       XmlParser.Node subNode = nodeIter.next();
 366       String service = getTextNode(subNode);
 367       appEngineWebXml.addInboundService(service);
 368     }
 369   }
 370
 371   private void processAdminConsoleNode(
 372       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 373     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "page");
 374     while (nodeIter.hasNext()) {
 375       XmlParser.Node subNode = nodeIter.next();
 376       String name = trim(subNode.getAttribute("name"));
 377       String url = trim(subNode.getAttribute("url"));
 378       appEngineWebXml.addAdminConsolePage(new AdminConsolePage(name, url));
 379     }
 380   }
 381
 382   private void processErrorHandlerNode(
 383       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 384     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "handler");
 385     while (nodeIter.hasNext()) {
 386       XmlParser.Node subNode = nodeIter.next();
 387       String file = trim(subNode.getAttribute("file"));
 388       String errorCode = trim(subNode.getAttribute("error-code"));
 389       appEngineWebXml.addErrorHandler(new ErrorHandler(file, errorCode));
 390     }
 391   }
 392
 393   private void processApiConfigNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 394     String servlet = trim(node.getAttribute("servlet-class"));
 395     String url = trim(node.getAttribute("url-pattern"));
 396     appEngineWebXml.setApiConfig(new ApiConfig(servlet, url));
 397
 398     String id = null;
 399     String endpoint = null;
 400     Iterator<XmlParser.Node> subNodeIter = getNodeIterator(node, "endpoint-servlet-mapping-id");
 401     while (subNodeIter.hasNext()) {
 402       XmlParser.Node subNode = subNodeIter.next();
 403       id = trim(getTextNode(subNode));
 404       if (id != null && id.length() > 0) {
 405         appEngineWebXml.addApiEndpoint(id);
 406       }
 407     }
 408   }
 409
 410   private void processPagespeedNode(XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 411     Pagespeed pagespeed = new Pagespeed();
 412     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "url-blacklist");
 413     while (nodeIter.hasNext()) {
 414       XmlParser.Node subNode = nodeIter.next();
 415       String urlMatcher = getTextNode(subNode);
 416       pagespeed.addUrlBlacklist(urlMatcher);
 417     }
 418     nodeIter = getNodeIterator(node, "domain-to-rewrite");
 419     while (nodeIter.hasNext()) {
 420       XmlParser.Node subNode = nodeIter.next();
 421       String domain = getTextNode(subNode);
 422       pagespeed.addDomainToRewrite(domain);
 423     }
 424     nodeIter = getNodeIterator(node, "enabled-rewriter");
 425     while (nodeIter.hasNext()) {
 426       XmlParser.Node subNode = nodeIter.next();
 427       String rewriter = getTextNode(subNode);
 428       pagespeed.addEnabledRewriter(rewriter);
 429     }
 430     nodeIter = getNodeIterator(node, "disabled-rewriter");
 431     while (nodeIter.hasNext()) {
 432       XmlParser.Node subNode = nodeIter.next();
 433       String rewriter = getTextNode(subNode);
 434       pagespeed.addDisabledRewriter(rewriter);
 435     }
 436     appEngineWebXml.setPagespeed(pagespeed);
 437   }
 438
 439   private void processClassLoaderConfig(
 440       XmlParser.Node node, AppEngineWebXml appEngineWebXml) {
 441     ClassLoaderConfig config = new ClassLoaderConfig();
 442     appEngineWebXml.setClassLoaderConfig(config);
 443     Iterator<XmlParser.Node> nodeIter = getNodeIterator(node, "priority-specifier");
 444     while (nodeIter.hasNext()) {
 445       processClassPathPrioritySpecifier(nodeIter.next(), config);
 446     }
 447   }
 448
 449   private void processClassPathPrioritySpecifier(Node node, ClassLoaderConfig config) {
 450     PrioritySpecifierEntry entry = new PrioritySpecifierEntry();
 451     entry.setFilename(node.getAttribute("filename"));
 452     entry.setPriority(node.getAttribute("priority"));
 453     entry.checkClassLoaderConfig();
 454     config.add(entry);
 455   }
 456
 457   private void processUrlStreamHandler(Node node, AppEngineWebXml appEngineWebXml) {
 458     appEngineWebXml.setUrlStreamHandlerType(getTextNode(node));
 459   }
 460
 461   private boolean getBooleanValue(XmlParser.Node node) {
 462     return toBoolean(getTextNode(node));
 463   }
 464
 465   private boolean getBooleanAttributeValue(XmlParser.Node node, String attribute) {
 466     return toBoolean(node.getAttribute(attribute));
 467   }
 468
 469   private boolean toBoolean(String value) {
 470     value = value.trim();
 471     return (value.equalsIgnoreCase("true") || value.equals("1"));
 472   }
 473
 474   private String getTextNode(XmlParser.Node node) {
 475     String value = (String) node.get(0);
 476     if (value == null) {
 477       value = "";
 478     }
 479     return value.trim();
 480   }
 481
 482   private String trim(String attribute) {
 483     return attribute == null ? null : attribute.trim();
 484   }
 485
 486   private void processUseGoogleConnectorJNode(XmlParser.Node node,
 487                                               AppEngineWebXml appEngineWebXml) {
 488     appEngineWebXml.setUseGoogleConnectorJ(getBooleanValue(node));
 489   }
 490 }