java/src/main/com/google/appengine/tools/admin/AppYamlTranslator.java

   1 // Copyright 2008 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.tools.admin;
   4
   5 import com.google.appengine.tools.info.Version;
   6 import com.google.apphosting.utils.config.AppEngineConfigException;
   7 import com.google.apphosting.utils.config.AppEngineWebXml;
   8 import com.google.apphosting.utils.config.AppEngineWebXml.AdminConsolePage;
   9 import com.google.apphosting.utils.config.AppEngineWebXml.ApiConfig;
  10 import com.google.apphosting.utils.config.AppEngineWebXml.CpuUtilization;
  11 import com.google.apphosting.utils.config.AppEngineWebXml.ErrorHandler;
  12 import com.google.apphosting.utils.config.AppEngineWebXml.Pagespeed;
  13 import com.google.apphosting.utils.config.AppEngineWebXml.HealthCheck;
  14 import com.google.apphosting.utils.config.AppEngineWebXml.Resources;
  15 import com.google.apphosting.utils.config.AppEngineWebXml.Network;
  16 import com.google.apphosting.utils.config.BackendsXml;
  17 import com.google.apphosting.utils.config.WebXml;
  18 import com.google.apphosting.utils.config.WebXml.SecurityConstraint;
  19 import com.google.apphosting.utils.glob.ConflictResolver;
  20 import com.google.apphosting.utils.glob.Glob;
  21 import com.google.apphosting.utils.glob.GlobFactory;
  22 import com.google.apphosting.utils.glob.GlobIntersector;
  23 import com.google.apphosting.utils.glob.LongestPatternConflictResolver;
  24 import com.google.common.collect.Maps;
  25
  26 import net.sourceforge.yamlbeans.YamlConfig;
  27 import net.sourceforge.yamlbeans.YamlException;
  28 import net.sourceforge.yamlbeans.YamlWriter;
  29
  30 import java.io.StringWriter;
  31 import java.util.ArrayList;
  32 import java.util.Collection;
  33 import java.util.Collections;
  34 import java.util.HashMap;
  35 import java.util.List;
  36 import java.util.Map;
  37 import java.util.Set;
  38
  39 /**
  40  * Generates {@code app.yaml} files suitable for uploading as part of
  41  * a Google App Engine application.
  42  *
  43  */
  44 public class AppYamlTranslator {
  45   private static final String NO_API_VERSION = "none";
  46
  47   private static final ConflictResolver RESOLVER =
  48       new LongestPatternConflictResolver();
  49
  50   private static final String DYNAMIC_PROPERTY = "dynamic";
  51   private static final String STATIC_PROPERTY = "static";
  52   private static final String WELCOME_FILES = "welcome";
  53   private static final String TRANSPORT_GUARANTEE_PROPERTY = "transportGuarantee";
  54   private static final String REQUIRED_ROLE_PROPERTY = "requiredRole";
  55   private static final String EXPIRATION_PROPERTY = "expiration";
  56   private static final String HTTP_HEADERS_PROPERTY = "http_headers";
  57   private static final String API_ENDPOINT_REGEX = "/_ah/spi/*";
  58
  59   private static final String[] PROPERTIES = new String[] {
  60     DYNAMIC_PROPERTY,
  61     STATIC_PROPERTY,
  62     WELCOME_FILES,
  63     TRANSPORT_GUARANTEE_PROPERTY,
  64     REQUIRED_ROLE_PROPERTY,
  65     EXPIRATION_PROPERTY,
  66   };
  67
  68   private static final int MAX_HANDLERS = 100;
  69
  70   private final AppEngineWebXml appEngineWebXml;
  71   private final WebXml webXml;
  72   private final BackendsXml backendsXml;
  73   private final String apiVersion;
  74   private final Set<String> staticFiles;
  75   private final String runtime;
  76   private final Version sdkVersion;
  77
  78   public AppYamlTranslator(AppEngineWebXml appEngineWebXml,
  79                            WebXml webXml,
  80                            BackendsXml backendsXml,
  81                            String apiVersion,
  82                            Set<String> staticFiles,
  83                            ApiConfig apiConfig,
  84                            String runtime,
  85                            Version sdkVersion) {
  86     this.appEngineWebXml = appEngineWebXml;
  87     this.webXml = webXml;
  88     this.backendsXml = backendsXml;
  89     this.apiVersion = apiVersion;
  90     this.staticFiles = staticFiles;
  91     this.runtime = runtime;
  92     this.sdkVersion = sdkVersion;
  93   }
  94
  95   public String getYaml() {
  96     StringBuilder builder = new StringBuilder();
  97     translateAppEngineWebXml(builder);
  98     translateApiVersion(builder);
  99     translateWebXml(builder);
 100     return builder.toString();
 101   }
 102
 103   private void appendIfNotNull(StringBuilder builder, String tag, Object value) {
 104     if (value != null) {
 105       builder.append(tag);
 106       builder.append(value);
 107       builder.append("\n");
 108     }
 109   }
 110
 111   private void appendIfNotZero(StringBuilder builder, String tag, double value) {
 112     if (value != 0) {
 113       builder.append(tag);
 114       builder.append(value);
 115       builder.append("\n");
 116     }
 117   }
 118
 119   private void translateAppEngineWebXml(StringBuilder builder) {
 120     if (appEngineWebXml.getAppId() != null) {
 121       builder.append("application: '" + appEngineWebXml.getAppId() + "'\n");
 122     }
 123     builder.append("runtime: " + runtime + "\n");
 124     if (appEngineWebXml.getUseVm()) {
 125       builder.append("vm: True\n");
 126     }
 127
 128     if (appEngineWebXml.getSourceLanguage() != null) {
 129       builder.append("source_language: '" + appEngineWebXml.getSourceLanguage() + "'\n");
 130     }
 131
 132     if (appEngineWebXml.getMajorVersionId() != null) {
 133       builder.append("version: '" + appEngineWebXml.getMajorVersionId() + "'\n");
 134     }
 135
 136     if (appEngineWebXml.getModule() != null) {
 137       builder.append("module: '" + appEngineWebXml.getModule() + "'\n");
 138     }
 139
 140     if (appEngineWebXml.getInstanceClass() != null) {
 141       builder.append("instance_class: " + appEngineWebXml.getInstanceClass() + "\n");
 142     }
 143
 144     if (!appEngineWebXml.getAutomaticScaling().isEmpty()) {
 145       builder.append("automatic_scaling:\n");
 146       AppEngineWebXml.AutomaticScaling settings = appEngineWebXml.getAutomaticScaling();
 147       appendIfNotNull(builder, "  min_pending_latency: ", settings.getMinPendingLatency());
 148       appendIfNotNull(builder, "  max_pending_latency: ", settings.getMaxPendingLatency());
 149       appendIfNotNull(builder, "  min_idle_instances: ", settings.getMinIdleInstances());
 150       appendIfNotNull(builder, "  max_idle_instances: ", settings.getMaxIdleInstances());
 151       appendIfNotNull(builder, "  max_concurrent_requests: ", settings.getMaxConcurrentRequests());
 152       appendIfNotNull(builder, "  min_num_instances: ", settings.getMinNumInstances());
 153       appendIfNotNull(builder, "  max_num_instances: ", settings.getMaxNumInstances());
 154       appendIfNotNull(builder, "  cool_down_period_sec: ", settings.getCoolDownPeriodSec());
 155       CpuUtilization cpuUtil = settings.getCpuUtilization();
 156       if (cpuUtil != null
 157           && (cpuUtil.getTargetUtilization() != null
 158               || cpuUtil.getAggregationWindowLengthSec() != null)) {
 159         builder.append("  cpu_utilization:\n");
 160         appendIfNotNull(builder, "    target_utilization: ", cpuUtil.getTargetUtilization());
 161         appendIfNotNull(
 162             builder, "    aggregation_window_length_sec: ",
 163             cpuUtil.getAggregationWindowLengthSec());
 164       }
 165     }
 166
 167     if (!appEngineWebXml.getManualScaling().isEmpty()) {
 168       builder.append("manual_scaling:\n");
 169       AppEngineWebXml.ManualScaling settings = appEngineWebXml.getManualScaling();
 170       builder.append("  instances: " + settings.getInstances() + "\n");
 171     }
 172
 173     if (!appEngineWebXml.getBasicScaling().isEmpty()) {
 174       builder.append("basic_scaling:\n");
 175       AppEngineWebXml.BasicScaling settings = appEngineWebXml.getBasicScaling();
 176       builder.append("  max_instances: " + settings.getMaxInstances() + "\n");
 177       appendIfNotNull(builder, "  idle_timeout: ", settings.getIdleTimeout());
 178     }
 179
 180     Collection<String> services = appEngineWebXml.getInboundServices();
 181     if (!services.isEmpty()) {
 182       builder.append("inbound_services:\n");
 183       for (String service : services) {
 184         builder.append("- " + service + "\n");
 185       }
 186     }
 187
 188     if (appEngineWebXml.getPrecompilationEnabled()) {
 189       builder.append("derived_file_type:\n");
 190       builder.append("- java_precompiled\n");
 191     }
 192
 193     if (appEngineWebXml.getThreadsafe()) {
 194       builder.append("threadsafe: True\n");
 195     }
 196
 197     if (appEngineWebXml.getAutoIdPolicy() != null) {
 198       builder.append("auto_id_policy: " + appEngineWebXml.getAutoIdPolicy() + "\n");
 199     } else {
 200       builder.append("auto_id_policy: default\n");
 201     }
 202
 203     if (appEngineWebXml.getCodeLock()) {
 204       builder.append("code_lock: True\n");
 205     }
 206
 207     List<AdminConsolePage> adminConsolePages = appEngineWebXml.getAdminConsolePages();
 208     if (!adminConsolePages.isEmpty()) {
 209       builder.append("admin_console:\n");
 210       builder.append("  pages:\n");
 211       for (AdminConsolePage page : adminConsolePages) {
 212         builder.append("  - name: " + page.getName() + "\n");
 213         builder.append("    url: " + page.getUrl() + "\n");
 214       }
 215     }
 216
 217     List<ErrorHandler> errorHandlers = appEngineWebXml.getErrorHandlers();
 218     if (!errorHandlers.isEmpty()) {
 219       builder.append("error_handlers:\n");
 220       for (ErrorHandler handler : errorHandlers) {
 221         String fileName = handler.getFile();
 222         if (!fileName.startsWith("/")) {
 223           fileName = "/" + fileName;
 224         }
 225         if (!staticFiles.contains("__static__" + fileName)) {
 226           throw new AppEngineConfigException("No static file found for error handler: "
 227               + fileName + ", out of " + staticFiles);
 228         }
 229         builder.append("- file: __static__" + fileName + "\n");
 230         if (handler.getErrorCode() != null) {
 231           builder.append("  error_code: " + handler.getErrorCode() + "\n");
 232         }
 233         String mimeType = webXml.getMimeTypeForPath(handler.getFile());
 234         if (mimeType != null) {
 235           builder.append("  mime_type: " + mimeType + "\n");
 236         }
 237       }
 238     }
 239
 240     if (backendsXml != null) {
 241       builder.append(backendsXml.toYaml());
 242     }
 243
 244     ApiConfig apiConfig = appEngineWebXml.getApiConfig();
 245     if (apiConfig != null) {
 246       builder.append("api_config:\n");
 247       builder.append("  url: " + apiConfig.getUrl() + "\n");
 248       builder.append("  script: unused\n");
 249     }
 250
 251     if (appEngineWebXml.getPagespeed() != null) {
 252       builder.append("pagespeed:\n");
 253       appendPagespeed(appEngineWebXml.getPagespeed(), builder, 2);
 254     }
 255
 256     if (appEngineWebXml.getUseVm()) {
 257       appendEnvVariables(appEngineWebXml.getEnvironmentVariables(), builder);
 258       appendBetaSettings(appEngineWebXml.getBetaSettings(), builder);
 259       appendHealthCheck(appEngineWebXml.getHealthCheck(), builder);
 260       appendResources(appEngineWebXml.getResources(), builder);
 261       appendNetwork(appEngineWebXml.getNetwork(), builder);
 262     }
 263   }
 264
 265   /**
 266    * Appends the given environment variables as YAML to the given StringBuilder.
 267    *
 268    * @param envVariables The env variables map to append as YAML.
 269    * @param builder The StringBuilder to append to.
 270    */
 271   private void appendEnvVariables(Map<String, String> envVariables, StringBuilder builder) {
 272     if (envVariables.size() > 0) {
 273       builder.append("env_variables:\n");
 274       for (Map.Entry<String, String> envVariable : envVariables.entrySet()) {
 275         String k = envVariable.getKey();
 276         String v = envVariable.getValue();
 277         builder.append("  ").append(yamlQuote(k)).append(": ").append(yamlQuote(v)).append("\n");
 278       }
 279     }
 280   }
 281
 282   /**
 283    * Appends the given Beta Settings as YAML to the given StringBuilder.
 284    *
 285    * @param betaSettings The beta settings map to append as YAML.
 286    * @param builder The StringBuilder to append to.
 287    */
 288   private void appendBetaSettings(Map<String, String> betaSettings, StringBuilder builder) {
 289     builder.append("beta_settings:\n");
 290     if (betaSettings == null || !betaSettings.containsKey("image")) {
 291       if (sdkVersion != null && sdkVersion.getRelease() != null) {
 292         builder.append("  'image': " + yamlQuote(sdkVersion.getRelease()) + "\n");
 293       }
 294     }
 295     if (betaSettings != null) {
 296       for (Map.Entry<String, String> setting : betaSettings.entrySet()) {
 297         builder.append(
 298             "  " + yamlQuote(setting.getKey()) + ": " + yamlQuote(setting.getValue()) + "\n");
 299       }
 300     }
 301   }
 302
 303   private void appendHealthCheck(HealthCheck healthCheck, StringBuilder builder) {
 304     builder.append("health_check:\n");
 305     if (healthCheck.getEnableHealthCheck()) {
 306       builder.append("  enable_health_check: True\n");
 307     } else {
 308       builder.append("  enable_health_check: False\n");
 309     }
 310
 311     appendIfNotNull(builder, "  check_interval_sec: ", healthCheck.getCheckIntervalSec());
 312     appendIfNotNull(builder, "  timeout_sec: ", healthCheck.getTimeoutSec());
 313     appendIfNotNull(builder, "  unhealthy_threshold: ", healthCheck.getUnhealthyThreshold());
 314     appendIfNotNull(builder, "  healthy_threshold: ", healthCheck.getHealthyThreshold());
 315     appendIfNotNull(builder, "  restart_threshold: ", healthCheck.getRestartThreshold());
 316     appendIfNotNull(builder, "  host: ", healthCheck.getHost());
 317   }
 318
 319   private void appendResources(Resources resources, StringBuilder builder) {
 320     if (!resources.isEmpty()) {
 321       builder.append("resources:\n");
 322       appendIfNotZero(builder, "  cpu: ", resources.getCpu());
 323       appendIfNotZero(builder, "  memory_gb: ", resources.getMemoryGb());
 324       appendIfNotZero(builder, "  disk_size_gb: ", resources.getDiskSizeGb());
 325     }
 326   }
 327
 328   private void appendNetwork(Network network, StringBuilder builder) {
 329     if (!network.isEmpty()) {
 330       builder.append("network:\n");
 331       appendIfNotNull(builder, "  instance_tag: ", network.getInstanceTag());
 332       if (!network.getForwardedPorts().isEmpty()) {
 333         builder.append("  forwarded_ports:\n");
 334         for (String forwardedPort : network.getForwardedPorts()) {
 335           builder.append("  - " + forwardedPort + "\n");
 336         }
 337       }
 338       appendIfNotNull(builder, "  name: ", network.getName());
 339     }
 340   }
 341
 342   /**
 343    * Append the given Pagespeed node as YAML to the given StringBuilder.
 344    * @param pagespeed The Pagespeed instance to append as YAML.
 345    * @param builder The StringBuilder to append to.
 346    * @param indent The number of spaces to indent the pagespeed YAML.
 347    */
 348   public static void appendPagespeed(Pagespeed pagespeed, StringBuilder builder, int indent) {
 349     if (pagespeed != null && !pagespeed.isEmpty()) {
 350       Map<String, List<String>> config = Maps.newTreeMap();
 351       putListInMapIfNotEmpty(config, "url_blacklist", pagespeed.getUrlBlacklist());
 352       putListInMapIfNotEmpty(config, "domains_to_rewrite", pagespeed.getDomainsToRewrite());
 353       putListInMapIfNotEmpty(config, "enabled_rewriters", pagespeed.getEnabledRewriters());
 354       putListInMapIfNotEmpty(config, "disabled_rewriters", pagespeed.getDisabledRewriters());
 355       appendObjectAsYaml(builder, config, indent);
 356     }
 357   }
 358
 359   /**
 360    * Adds the list to the given map, using the specified name, if the list is non-null and not
 361    * empty.
 362    */
 363   private static void putListInMapIfNotEmpty(Map<String, List<String>> map, String name,
 364       List<String> values) {
 365     if (values != null && !values.isEmpty()) {
 366       map.put(name, values);
 367     }
 368   }
 369
 370   /**
 371    * Appends the given collection to the StringBuilder as YAML, indenting each emitted line by
 372    * numIndentSpaces.
 373    */
 374   private static void appendObjectAsYaml(
 375       StringBuilder builder, Object collection, int numIndentSpaces) {
 376     StringBuilder prefixBuilder = new StringBuilder();
 377     for (int i = 0; i < numIndentSpaces; ++i) {
 378       prefixBuilder.append(' ');
 379     }
 380     final String indentPrefix = prefixBuilder.toString();
 381
 382     StringWriter stringWriter = new StringWriter();
 383     YamlConfig yamlConfig = new YamlConfig();
 384     yamlConfig.writeConfig.setIndentSize(2);
 385     yamlConfig.writeConfig.setWriteRootTags(false);
 386
 387     YamlWriter writer = new YamlWriter(stringWriter, yamlConfig);
 388     try {
 389       writer.write(collection);
 390       writer.close();
 391     } catch (YamlException e) {
 392       throw new AppEngineConfigException("Unable to generate YAML.", e);
 393     }
 394
 395     for (String line : stringWriter.toString().split("\n")) {
 396       builder.append(indentPrefix);
 397       builder.append(line);
 398       builder.append("\n");
 399     }
 400   }
 401
 402   /**
 403    * Surrounds the provided string with single quotes, escaping any single
 404    * quotes in the string by replacing them with ''.
 405    */
 406   private String yamlQuote(String str) {
 407     return "'" + str.replace("'", "''") + "'";
 408   }
 409
 410   private void translateApiVersion(StringBuilder builder) {
 411     if (apiVersion == null) {
 412       builder.append("api_version: '" + NO_API_VERSION + "'\n");
 413     } else {
 414       builder.append("api_version: '" + apiVersion + "'\n");
 415     }
 416   }
 417
 418   private void translateWebXml(StringBuilder builder) {
 419     builder.append("handlers:\n");
 420
 421     AbstractHandlerGenerator staticGenerator = null;
 422     if (staticFiles.isEmpty()) {
 423       staticGenerator = new EmptyHandlerGenerator();
 424     } else {
 425       staticGenerator = new StaticHandlerGenerator(appEngineWebXml.getPublicRoot());
 426     }
 427
 428     DynamicHandlerGenerator dynamicGenerator =
 429         new DynamicHandlerGenerator(webXml.getFallThroughToRuntime());
 430     if (staticGenerator.size() + dynamicGenerator.size() > MAX_HANDLERS) {
 431       dynamicGenerator = new DynamicHandlerGenerator(true);
 432     }
 433
 434     staticGenerator.translate(builder);
 435     dynamicGenerator.translate(builder);
 436   }
 437
 438   class StaticHandlerGenerator extends AbstractHandlerGenerator {
 439     private final String root;
 440
 441     public StaticHandlerGenerator(String root) {
 442       this.root = root;
 443     }
 444
 445     @Override
 446     protected Map<String, Object> getWelcomeProperties() {
 447       List<String> staticWelcomeFiles = new ArrayList<String>();
 448       for (String welcomeFile : webXml.getWelcomeFiles()) {
 449         for (String staticFile : staticFiles) {
 450           if (staticFile.endsWith("/" + welcomeFile)) {
 451             staticWelcomeFiles.add(welcomeFile);
 452             break;
 453           }
 454         }
 455       }
 456       return Collections.<String,Object>singletonMap(WELCOME_FILES, staticWelcomeFiles);
 457     }
 458
 459     @Override
 460     protected void addPatterns(GlobIntersector intersector) {
 461       List<AppEngineWebXml.StaticFileInclude> includes = appEngineWebXml.getStaticFileIncludes();
 462       if (includes.isEmpty()) {
 463         intersector.addGlob(GlobFactory.createGlob("/*", STATIC_PROPERTY, true));
 464       } else {
 465         for (AppEngineWebXml.StaticFileInclude include : includes) {
 466           String pattern = include.getPattern().replaceAll("\\*\\*", "*");
 467           if (!pattern.startsWith("/")) {
 468             pattern = "/" + pattern;
 469           }
 470           Map<String, Object> props = new HashMap<String, Object>();
 471           props.put(STATIC_PROPERTY, true);
 472           if (include.getExpiration() != null) {
 473             props.put(EXPIRATION_PROPERTY, include.getExpiration());
 474           }
 475           if (include.getHttpHeaders() != null) {
 476             props.put(HTTP_HEADERS_PROPERTY, include.getHttpHeaders());
 477           }
 478
 479           intersector.addGlob(GlobFactory.createGlob(pattern, props));
 480         }
 481       }
 482     }
 483
 484     @Override
 485     public void translateGlob(StringBuilder builder, Glob glob) {
 486       String regex = glob.getRegularExpression().pattern();
 487       if (!root.isEmpty()) {
 488         if (regex.startsWith(root)){
 489           regex = regex.substring(root.length(), regex.length());
 490         }
 491       }
 492       @SuppressWarnings("unchecked")
 493       List<String> welcomeFiles =
 494           (List<String>) glob.getProperty(WELCOME_FILES, RESOLVER);
 495       if (welcomeFiles != null) {
 496         for (String welcomeFile : welcomeFiles) {
 497           builder.append("- url: (" + regex + ")\n");
 498           builder.append("  static_files: __static__" + root + "\\1" + welcomeFile + "\n");
 499           builder.append("  upload: __NOT_USED__\n");
 500           builder.append("  require_matching_file: True\n");
 501           translateHandlerOptions(builder, glob);
 502           translateAdditionalStaticOptions(builder, glob);
 503         }
 504       } else {
 505         Boolean isStatic = (Boolean) glob.getProperty(STATIC_PROPERTY, RESOLVER);
 506         if (isStatic != null && isStatic.booleanValue()) {
 507           builder.append("- url: (" + regex + ")\n");
 508           builder.append("  static_files: __static__" + root + "\\1\n");
 509           builder.append("  upload: __NOT_USED__\n");
 510           builder.append("  require_matching_file: True\n");
 511           translateHandlerOptions(builder, glob);
 512           translateAdditionalStaticOptions(builder, glob);
 513         }
 514       }
 515     }
 516
 517     private void translateAdditionalStaticOptions(StringBuilder builder, Glob glob)
 518         throws AppEngineConfigException {
 519       String expiration = (String) glob.getProperty(EXPIRATION_PROPERTY, RESOLVER);
 520       if (expiration != null) {
 521         builder.append("  expiration: " + expiration + "\n");
 522       }
 523
 524       @SuppressWarnings("unchecked")
 525       Map<String, String> httpHeaders =
 526           (Map<String, String>) glob.getProperty(HTTP_HEADERS_PROPERTY, RESOLVER);
 527       if (httpHeaders != null && !httpHeaders.isEmpty()) {
 528         builder.append("  http_headers:\n");
 529         appendObjectAsYaml(builder, httpHeaders, 4);
 530       }
 531     }
 532   }
 533
 534   /**
 535    * According to the example In section 12.2.2 of Servlet Spec 3.0 , /baz/* should also match /baz,
 536    * so add an additional glob for that.
 537    */
 538   private static void extendMeaningOfTrailingStar(
 539       GlobIntersector intersector, String pattern, String property, Object value) {
 540     if (pattern.endsWith("/*") && pattern.length() > 2) {
 541       intersector.addGlob(
 542           GlobFactory.createGlob(pattern.substring(0, pattern.length() - 2), property, value));
 543     }
 544   }
 545
 546   class DynamicHandlerGenerator extends AbstractHandlerGenerator {
 547     private final List<String> patterns;
 548     private boolean fallthrough;
 549     private boolean hasJsps;
 550
 551     DynamicHandlerGenerator(boolean alwaysFallthrough) {
 552       fallthrough = alwaysFallthrough;
 553       patterns = new ArrayList<String>();
 554       for (String servletPattern : webXml.getServletPatterns()) {
 555         if (servletPattern.equals("/") || servletPattern.equals("/*")) {
 556           fallthrough = true;
 557         } else if (servletPattern.equals(API_ENDPOINT_REGEX)) {
 558           hasApiEndpoint = true;
 559         } else if (servletPattern.endsWith(".jsp")) {
 560           hasJsps = true;
 561         } else {
 562           patterns.add(servletPattern);
 563         }
 564       }
 565     }
 566
 567     @Override
 568     protected Map<String, Object> getWelcomeProperties() {
 569       if (fallthrough) {
 570         return null;
 571       } else {
 572         return Collections.<String,Object>singletonMap(DYNAMIC_PROPERTY, true);
 573       }
 574     }
 575
 576     @Override
 577     protected void addPatterns(GlobIntersector intersector) {
 578       if (fallthrough) {
 579         intersector.addGlob(GlobFactory.createGlob(
 580             "/*",
 581             DYNAMIC_PROPERTY, true));
 582       } else {
 583         for (String servletPattern : patterns) {
 584           intersector.addGlob(GlobFactory.createGlob(
 585               servletPattern,
 586               DYNAMIC_PROPERTY, true));
 587           extendMeaningOfTrailingStar(intersector, servletPattern, DYNAMIC_PROPERTY, true);
 588         }
 589         if (hasJsps) {
 590           intersector.addGlob(GlobFactory.createGlob(
 591               "*.jsp",
 592               DYNAMIC_PROPERTY, true));
 593         } else if (appEngineWebXml.getUseVm()) {
 594           intersector.addGlob(GlobFactory.createGlob(
 595               "*.jsp",
 596               DYNAMIC_PROPERTY, true));
 597         }
 598         intersector.addGlob(GlobFactory.createGlob(
 599             "/_ah/*",
 600             DYNAMIC_PROPERTY, true));
 601       }
 602     }
 603
 604     @Override
 605     public void translateGlob(StringBuilder builder, Glob glob) {
 606       String regex = glob.getRegularExpression().pattern();
 607
 608       Boolean isDynamic = (Boolean) glob.getProperty(DYNAMIC_PROPERTY, RESOLVER);
 609       if (isDynamic != null && isDynamic.booleanValue()) {
 610         builder.append("- url: " + regex + "\n");
 611         builder.append("  script: unused\n");
 612         translateHandlerOptions(builder, glob);
 613       }
 614     }
 615   }
 616
 617   /**
 618    * An {@code AbstractHandlerGenerator} that returns no globs.
 619    */
 620   class EmptyHandlerGenerator extends AbstractHandlerGenerator {
 621     @Override
 622     protected void addPatterns(GlobIntersector intersector) {
 623     }
 624
 625     @Override
 626     protected void translateGlob(StringBuilder builder, Glob glob) {
 627     }
 628
 629     @Override
 630     protected Map<String, Object> getWelcomeProperties() {
 631       return Collections.emptyMap();
 632     }
 633   }
 634
 635   abstract class AbstractHandlerGenerator {
 636     private List<Glob> globs = null;
 637     protected boolean hasApiEndpoint;
 638
 639     public int size() {
 640       return getGlobPatterns().size();
 641     }
 642
 643     public void translate(StringBuilder builder) {
 644       for (Glob glob : getGlobPatterns()) {
 645         translateGlob(builder, glob);
 646       }
 647     }
 648
 649     abstract protected void addPatterns(GlobIntersector intersector);
 650     abstract protected void translateGlob(StringBuilder builder, Glob glob);
 651
 652     /**
 653      * @returns a map of welcome properties to apply to the welcome
 654      * file entries, or {@code null} if no welcome file entries are
 655      * necessary.
 656      */
 657     abstract protected Map<String, Object> getWelcomeProperties();
 658
 659     protected List<Glob> getGlobPatterns() {
 660       if (globs == null) {
 661         GlobIntersector intersector = new GlobIntersector();
 662         addPatterns(intersector);
 663         addSecurityConstraints(intersector);
 664         addWelcomeFiles(intersector);
 665
 666         globs = intersector.getIntersection();
 667         removeNearDuplicates(globs);
 668         if (hasApiEndpoint) {
 669           globs.add(GlobFactory.createGlob(API_ENDPOINT_REGEX, DYNAMIC_PROPERTY, true));
 670         }
 671       }
 672       return globs;
 673     }
 674
 675     protected void addWelcomeFiles(GlobIntersector intersector) {
 676       Map<String, Object> welcomeProperties = getWelcomeProperties();
 677       if (welcomeProperties != null) {
 678         intersector.addGlob(GlobFactory.createGlob("/", welcomeProperties));
 679         intersector.addGlob(GlobFactory.createGlob("/*/", welcomeProperties));
 680       }
 681     }
 682
 683     protected void addSecurityConstraints(GlobIntersector intersector) {
 684       for (SecurityConstraint constraint : webXml.getSecurityConstraints()) {
 685         for (String pattern : constraint.getUrlPatterns()) {
 686           intersector.addGlob(GlobFactory.createGlob(
 687               pattern,
 688               TRANSPORT_GUARANTEE_PROPERTY,
 689               constraint.getTransportGuarantee()));
 690           extendMeaningOfTrailingStar(intersector, pattern, TRANSPORT_GUARANTEE_PROPERTY,
 691               constraint.getTransportGuarantee());
 692           intersector.addGlob(GlobFactory.createGlob(
 693               pattern,
 694               REQUIRED_ROLE_PROPERTY,
 695               constraint.getRequiredRole()));
 696           extendMeaningOfTrailingStar(
 697               intersector, pattern, REQUIRED_ROLE_PROPERTY, constraint.getRequiredRole());
 698         }
 699       }
 700     }
 701
 702     protected void translateHandlerOptions(StringBuilder builder, Glob glob) {
 703       SecurityConstraint.RequiredRole requiredRole =
 704           (SecurityConstraint.RequiredRole) glob.getProperty(REQUIRED_ROLE_PROPERTY, RESOLVER);
 705       if (requiredRole == null) {
 706         requiredRole = SecurityConstraint.RequiredRole.NONE;
 707       }
 708       switch (requiredRole) {
 709         case NONE:
 710           builder.append("  login: optional\n");
 711           break;
 712         case ANY_USER:
 713           builder.append("  login: required\n");
 714           break;
 715         case ADMIN:
 716           builder.append("  login: admin\n");
 717           break;
 718       }
 719
 720       SecurityConstraint.TransportGuarantee transportGuarantee =
 721           (SecurityConstraint.TransportGuarantee) glob.getProperty(TRANSPORT_GUARANTEE_PROPERTY,
 722                                                                    RESOLVER);
 723       if (transportGuarantee == null) {
 724         transportGuarantee = SecurityConstraint.TransportGuarantee.NONE;
 725       }
 726       switch (transportGuarantee) {
 727         case NONE:
 728           if (appEngineWebXml.getSslEnabled()) {
 729             builder.append("  secure: optional\n");
 730           } else {
 731             builder.append("  secure: never\n");
 732           }
 733           break;
 734         case INTEGRAL:
 735         case CONFIDENTIAL:
 736           if (!appEngineWebXml.getSslEnabled()) {
 737             throw new AppEngineConfigException(
 738                 "SSL must be enabled in appengine-web.xml to use transport-guarantee");
 739           }
 740           builder.append("  secure: always\n");
 741           break;
 742       }
 743
 744       String pattern = glob.getRegularExpression().pattern();
 745       String id = webXml.getHandlerIdForPattern(pattern);
 746       if (id != null) {
 747         if (appEngineWebXml.isApiEndpoint(id)) {
 748           builder.append("  api_endpoint: True\n");
 749         }
 750       }
 751     }
 752
 753     private void removeNearDuplicates(List<Glob> globs) {
 754       for (int i = 0; i < globs.size(); i++) {
 755         Glob topGlob = globs.get(i);
 756         for (int j = i + 1; j < globs.size(); j++) {
 757           Glob bottomGlob = globs.get(j);
 758           if (bottomGlob.matchesAll(topGlob)) {
 759             if (propertiesMatch(topGlob, bottomGlob)) {
 760               globs.remove(i);
 761               i--;
 762             }
 763             break;
 764           }
 765         }
 766       }
 767     }
 768
 769     private boolean propertiesMatch(Glob glob1, Glob glob2) {
 770       for (String property : PROPERTIES) {
 771         Object value1 = glob1.getProperty(property, RESOLVER);
 772         Object value2 = glob2.getProperty(property, RESOLVER);
 773         if (value1 != value2 && (value1 == null || !value1.equals(value2))) {
 774           return false;
 775         }
 776       }
 777       return true;
 778     }
 779   }
 780 }