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.getEnv().equals("1")) {
 129       builder.append("env: " + appEngineWebXml.getEnv() + "\n");
 130     }
 131
 132     if (appEngineWebXml.getSourceLanguage() != null) {
 133       builder.append("source_language: '" + appEngineWebXml.getSourceLanguage() + "'\n");
 134     }
 135
 136     if (appEngineWebXml.getMajorVersionId() != null) {
 137       builder.append("version: '" + appEngineWebXml.getMajorVersionId() + "'\n");
 138     }
 139
 140     if (appEngineWebXml.getModule() != null) {
 141       builder.append("module: '" + appEngineWebXml.getModule() + "'\n");
 142     }
 143
 144     if (appEngineWebXml.getInstanceClass() != null) {
 145       builder.append("instance_class: " + appEngineWebXml.getInstanceClass() + "\n");
 146     }
 147
 148     if (!appEngineWebXml.getAutomaticScaling().isEmpty()) {
 149       builder.append("automatic_scaling:\n");
 150       AppEngineWebXml.AutomaticScaling settings = appEngineWebXml.getAutomaticScaling();
 151       appendIfNotNull(builder, "  min_pending_latency: ", settings.getMinPendingLatency());
 152       appendIfNotNull(builder, "  max_pending_latency: ", settings.getMaxPendingLatency());
 153       appendIfNotNull(builder, "  min_idle_instances: ", settings.getMinIdleInstances());
 154       appendIfNotNull(builder, "  max_idle_instances: ", settings.getMaxIdleInstances());
 155       appendIfNotNull(builder, "  max_concurrent_requests: ", settings.getMaxConcurrentRequests());
 156       appendIfNotNull(builder, "  min_num_instances: ", settings.getMinNumInstances());
 157       appendIfNotNull(builder, "  max_num_instances: ", settings.getMaxNumInstances());
 158       appendIfNotNull(builder, "  cool_down_period_sec: ", settings.getCoolDownPeriodSec());
 159
 160       CpuUtilization cpuUtil = settings.getCpuUtilization();
 161       if (cpuUtil != null
 162           && (cpuUtil.getTargetUtilization() != null
 163               || cpuUtil.getAggregationWindowLengthSec() != null)) {
 164         builder.append("  cpu_utilization:\n");
 165         appendIfNotNull(builder, "    target_utilization: ", cpuUtil.getTargetUtilization());
 166         appendIfNotNull(
 167             builder, "    aggregation_window_length_sec: ",
 168             cpuUtil.getAggregationWindowLengthSec());
 169       }
 170
 171       appendIfNotNull(
 172           builder, "  target_network_sent_bytes_per_sec: ",
 173           settings.getTargetNetworkSentBytesPerSec());
 174       appendIfNotNull(
 175           builder, "  target_network_sent_packets_per_sec: ",
 176           settings.getTargetNetworkSentPacketsPerSec());
 177       appendIfNotNull(
 178           builder, "  target_network_received_bytes_per_sec: ",
 179           settings.getTargetNetworkReceivedBytesPerSec());
 180       appendIfNotNull(
 181           builder, "  target_network_received_packets_per_sec: ",
 182           settings.getTargetNetworkReceivedPacketsPerSec());
 183       appendIfNotNull(
 184           builder, "  target_disk_write_bytes_per_sec: ",
 185           settings.getTargetDiskWriteBytesPerSec());
 186       appendIfNotNull(
 187           builder, "  target_disk_write_ops_per_sec: ",
 188           settings.getTargetDiskWriteOpsPerSec());
 189       appendIfNotNull(
 190           builder, "  target_disk_read_bytes_per_sec: ",
 191           settings.getTargetDiskReadBytesPerSec());
 192       appendIfNotNull(
 193           builder, "  target_disk_read_ops_per_sec: ",
 194           settings.getTargetDiskReadOpsPerSec());
 195       appendIfNotNull(
 196           builder, "  target_request_count_per_sec: ",
 197           settings.getTargetRequestCountPerSec());
 198       appendIfNotNull(
 199           builder, "  target_concurrent_requests: ",
 200           settings.getTargetConcurrentRequests());
 201     }
 202
 203     if (!appEngineWebXml.getManualScaling().isEmpty()) {
 204       builder.append("manual_scaling:\n");
 205       AppEngineWebXml.ManualScaling settings = appEngineWebXml.getManualScaling();
 206       builder.append("  instances: " + settings.getInstances() + "\n");
 207     }
 208
 209     if (!appEngineWebXml.getBasicScaling().isEmpty()) {
 210       builder.append("basic_scaling:\n");
 211       AppEngineWebXml.BasicScaling settings = appEngineWebXml.getBasicScaling();
 212       builder.append("  max_instances: " + settings.getMaxInstances() + "\n");
 213       appendIfNotNull(builder, "  idle_timeout: ", settings.getIdleTimeout());
 214     }
 215
 216     Collection<String> services = appEngineWebXml.getInboundServices();
 217     if (!services.isEmpty()) {
 218       builder.append("inbound_services:\n");
 219       for (String service : services) {
 220         builder.append("- " + service + "\n");
 221       }
 222     }
 223
 224     if (appEngineWebXml.getPrecompilationEnabled()) {
 225       builder.append("derived_file_type:\n");
 226       builder.append("- java_precompiled\n");
 227     }
 228
 229     if (appEngineWebXml.getThreadsafe()) {
 230       builder.append("threadsafe: True\n");
 231     }
 232
 233     if (appEngineWebXml.getAutoIdPolicy() != null) {
 234       builder.append("auto_id_policy: " + appEngineWebXml.getAutoIdPolicy() + "\n");
 235     } else {
 236       builder.append("auto_id_policy: default\n");
 237     }
 238
 239     if (appEngineWebXml.getCodeLock()) {
 240       builder.append("code_lock: True\n");
 241     }
 242
 243     List<AdminConsolePage> adminConsolePages = appEngineWebXml.getAdminConsolePages();
 244     if (!adminConsolePages.isEmpty()) {
 245       builder.append("admin_console:\n");
 246       builder.append("  pages:\n");
 247       for (AdminConsolePage page : adminConsolePages) {
 248         builder.append("  - name: " + page.getName() + "\n");
 249         builder.append("    url: " + page.getUrl() + "\n");
 250       }
 251     }
 252
 253     List<ErrorHandler> errorHandlers = appEngineWebXml.getErrorHandlers();
 254     if (!errorHandlers.isEmpty()) {
 255       builder.append("error_handlers:\n");
 256       for (ErrorHandler handler : errorHandlers) {
 257         String fileName = handler.getFile();
 258         if (!fileName.startsWith("/")) {
 259           fileName = "/" + fileName;
 260         }
 261         if (!staticFiles.contains("__static__" + fileName)) {
 262           throw new AppEngineConfigException("No static file found for error handler: "
 263               + fileName + ", out of " + staticFiles);
 264         }
 265         builder.append("- file: __static__" + fileName + "\n");
 266         if (handler.getErrorCode() != null) {
 267           builder.append("  error_code: " + handler.getErrorCode() + "\n");
 268         }
 269         String mimeType = webXml.getMimeTypeForPath(handler.getFile());
 270         if (mimeType != null) {
 271           builder.append("  mime_type: " + mimeType + "\n");
 272         }
 273       }
 274     }
 275
 276     if (backendsXml != null) {
 277       builder.append(backendsXml.toYaml());
 278     }
 279
 280     ApiConfig apiConfig = appEngineWebXml.getApiConfig();
 281     if (apiConfig != null) {
 282       builder.append("api_config:\n");
 283       builder.append("  url: " + apiConfig.getUrl() + "\n");
 284       builder.append("  script: unused\n");
 285     }
 286
 287     if (appEngineWebXml.getPagespeed() != null) {
 288       builder.append("pagespeed:\n");
 289       appendPagespeed(appEngineWebXml.getPagespeed(), builder, 2);
 290     }
 291
 292     if (appEngineWebXml.getUseVm() || appEngineWebXml.getEnv().equals("2")) {
 293       appendEnvVariables(appEngineWebXml.getEnvironmentVariables(), builder);
 294       appendBetaSettings(appEngineWebXml.getBetaSettings(), builder);
 295       appendHealthCheck(appEngineWebXml.getHealthCheck(), builder);
 296       appendResources(appEngineWebXml.getResources(), builder);
 297       appendNetwork(appEngineWebXml.getNetwork(), builder);
 298     }
 299   }
 300
 301   /**
 302    * Appends the given environment variables as YAML to the given StringBuilder.
 303    *
 304    * @param envVariables The env variables map to append as YAML.
 305    * @param builder The StringBuilder to append to.
 306    */
 307   private void appendEnvVariables(Map<String, String> envVariables, StringBuilder builder) {
 308     if (envVariables.size() > 0) {
 309       builder.append("env_variables:\n");
 310       for (Map.Entry<String, String> envVariable : envVariables.entrySet()) {
 311         String k = envVariable.getKey();
 312         String v = envVariable.getValue();
 313         builder.append("  ").append(yamlQuote(k)).append(": ").append(yamlQuote(v)).append("\n");
 314       }
 315     }
 316   }
 317
 318   /**
 319    * Appends the given Beta Settings as YAML to the given StringBuilder.
 320    *
 321    * @param betaSettings The beta settings map to append as YAML.
 322    * @param builder The StringBuilder to append to.
 323    */
 324   private void appendBetaSettings(Map<String, String> betaSettings, StringBuilder builder) {
 325     if (betaSettings != null && !betaSettings.isEmpty()) {
 326       builder.append("beta_settings:\n");
 327       for (Map.Entry<String, String> setting : betaSettings.entrySet()) {
 328         builder.append(
 329             "  " + yamlQuote(setting.getKey()) + ": " + yamlQuote(setting.getValue()) + "\n");
 330       }
 331     }
 332   }
 333
 334   private void appendHealthCheck(HealthCheck healthCheck, StringBuilder builder) {
 335     builder.append("health_check:\n");
 336     if (healthCheck.getEnableHealthCheck()) {
 337       builder.append("  enable_health_check: True\n");
 338     } else {
 339       builder.append("  enable_health_check: False\n");
 340     }
 341
 342     appendIfNotNull(builder, "  check_interval_sec: ", healthCheck.getCheckIntervalSec());
 343     appendIfNotNull(builder, "  timeout_sec: ", healthCheck.getTimeoutSec());
 344     appendIfNotNull(builder, "  unhealthy_threshold: ", healthCheck.getUnhealthyThreshold());
 345     appendIfNotNull(builder, "  healthy_threshold: ", healthCheck.getHealthyThreshold());
 346     appendIfNotNull(builder, "  restart_threshold: ", healthCheck.getRestartThreshold());
 347     appendIfNotNull(builder, "  host: ", healthCheck.getHost());
 348   }
 349
 350   private void appendResources(Resources resources, StringBuilder builder) {
 351     if (!resources.isEmpty()) {
 352       builder.append("resources:\n");
 353       appendIfNotZero(builder, "  cpu: ", resources.getCpu());
 354       appendIfNotZero(builder, "  memory_gb: ", resources.getMemoryGb());
 355       appendIfNotZero(builder, "  disk_size_gb: ", resources.getDiskSizeGb());
 356     }
 357   }
 358
 359   private void appendNetwork(Network network, StringBuilder builder) {
 360     if (!network.isEmpty()) {
 361       builder.append("network:\n");
 362       appendIfNotNull(builder, "  instance_tag: ", network.getInstanceTag());
 363       if (!network.getForwardedPorts().isEmpty()) {
 364         builder.append("  forwarded_ports:\n");
 365         for (String forwardedPort : network.getForwardedPorts()) {
 366           builder.append("  - " + forwardedPort + "\n");
 367         }
 368       }
 369       appendIfNotNull(builder, "  name: ", network.getName());
 370     }
 371   }
 372
 373   /**
 374    * Append the given Pagespeed node as YAML to the given StringBuilder.
 375    * @param pagespeed The Pagespeed instance to append as YAML.
 376    * @param builder The StringBuilder to append to.
 377    * @param indent The number of spaces to indent the pagespeed YAML.
 378    */
 379   public static void appendPagespeed(Pagespeed pagespeed, StringBuilder builder, int indent) {
 380     if (pagespeed != null && !pagespeed.isEmpty()) {
 381       Map<String, List<String>> config = Maps.newTreeMap();
 382       putListInMapIfNotEmpty(config, "url_blacklist", pagespeed.getUrlBlacklist());
 383       putListInMapIfNotEmpty(config, "domains_to_rewrite", pagespeed.getDomainsToRewrite());
 384       putListInMapIfNotEmpty(config, "enabled_rewriters", pagespeed.getEnabledRewriters());
 385       putListInMapIfNotEmpty(config, "disabled_rewriters", pagespeed.getDisabledRewriters());
 386       appendObjectAsYaml(builder, config, indent);
 387     }
 388   }
 389
 390   /**
 391    * Adds the list to the given map, using the specified name, if the list is non-null and not
 392    * empty.
 393    */
 394   private static void putListInMapIfNotEmpty(Map<String, List<String>> map, String name,
 395       List<String> values) {
 396     if (values != null && !values.isEmpty()) {
 397       map.put(name, values);
 398     }
 399   }
 400
 401   /**
 402    * Appends the given collection to the StringBuilder as YAML, indenting each emitted line by
 403    * numIndentSpaces.
 404    */
 405   private static void appendObjectAsYaml(
 406       StringBuilder builder, Object collection, int numIndentSpaces) {
 407     StringBuilder prefixBuilder = new StringBuilder();
 408     for (int i = 0; i < numIndentSpaces; ++i) {
 409       prefixBuilder.append(' ');
 410     }
 411     final String indentPrefix = prefixBuilder.toString();
 412
 413     StringWriter stringWriter = new StringWriter();
 414     YamlConfig yamlConfig = new YamlConfig();
 415     yamlConfig.writeConfig.setIndentSize(2);
 416     yamlConfig.writeConfig.setWriteRootTags(false);
 417
 418     YamlWriter writer = new YamlWriter(stringWriter, yamlConfig);
 419     try {
 420       writer.write(collection);
 421       writer.close();
 422     } catch (YamlException e) {
 423       throw new AppEngineConfigException("Unable to generate YAML.", e);
 424     }
 425
 426     for (String line : stringWriter.toString().split("\n")) {
 427       builder.append(indentPrefix);
 428       builder.append(line);
 429       builder.append("\n");
 430     }
 431   }
 432
 433   /**
 434    * Surrounds the provided string with single quotes, escaping any single
 435    * quotes in the string by replacing them with ''.
 436    */
 437   private String yamlQuote(String str) {
 438     return "'" + str.replace("'", "''") + "'";
 439   }
 440
 441   private void translateApiVersion(StringBuilder builder) {
 442     if (apiVersion == null) {
 443       builder.append("api_version: '" + NO_API_VERSION + "'\n");
 444     } else {
 445       builder.append("api_version: '" + apiVersion + "'\n");
 446     }
 447   }
 448
 449   private void translateWebXml(StringBuilder builder) {
 450     builder.append("handlers:\n");
 451
 452     AbstractHandlerGenerator staticGenerator = null;
 453     if (staticFiles.isEmpty()) {
 454       staticGenerator = new EmptyHandlerGenerator();
 455     } else {
 456       staticGenerator = new StaticHandlerGenerator(appEngineWebXml.getPublicRoot());
 457     }
 458
 459     DynamicHandlerGenerator dynamicGenerator =
 460         new DynamicHandlerGenerator(webXml.getFallThroughToRuntime());
 461     if (staticGenerator.size() + dynamicGenerator.size() > MAX_HANDLERS) {
 462       dynamicGenerator = new DynamicHandlerGenerator(true);
 463     }
 464
 465     staticGenerator.translate(builder);
 466     dynamicGenerator.translate(builder);
 467   }
 468
 469   class StaticHandlerGenerator extends AbstractHandlerGenerator {
 470     private final String root;
 471
 472     public StaticHandlerGenerator(String root) {
 473       this.root = root;
 474     }
 475
 476     @Override
 477     protected Map<String, Object> getWelcomeProperties() {
 478       List<String> staticWelcomeFiles = new ArrayList<String>();
 479       for (String welcomeFile : webXml.getWelcomeFiles()) {
 480         for (String staticFile : staticFiles) {
 481           if (staticFile.endsWith("/" + welcomeFile)) {
 482             staticWelcomeFiles.add(welcomeFile);
 483             break;
 484           }
 485         }
 486       }
 487       return Collections.<String,Object>singletonMap(WELCOME_FILES, staticWelcomeFiles);
 488     }
 489
 490     @Override
 491     protected void addPatterns(GlobIntersector intersector) {
 492       List<AppEngineWebXml.StaticFileInclude> includes = appEngineWebXml.getStaticFileIncludes();
 493       if (includes.isEmpty()) {
 494         intersector.addGlob(GlobFactory.createGlob("/*", STATIC_PROPERTY, true));
 495       } else {
 496         for (AppEngineWebXml.StaticFileInclude include : includes) {
 497           String pattern = include.getPattern().replaceAll("\\*\\*", "*");
 498           if (!pattern.startsWith("/")) {
 499             pattern = "/" + pattern;
 500           }
 501           Map<String, Object> props = new HashMap<String, Object>();
 502           props.put(STATIC_PROPERTY, true);
 503           if (include.getExpiration() != null) {
 504             props.put(EXPIRATION_PROPERTY, include.getExpiration());
 505           }
 506           if (include.getHttpHeaders() != null) {
 507             props.put(HTTP_HEADERS_PROPERTY, include.getHttpHeaders());
 508           }
 509
 510           intersector.addGlob(GlobFactory.createGlob(pattern, props));
 511         }
 512       }
 513     }
 514
 515     @Override
 516     public void translateGlob(StringBuilder builder, Glob glob) {
 517       String regex = glob.getRegularExpression().pattern();
 518       if (!root.isEmpty()) {
 519         if (regex.startsWith(root)){
 520           regex = regex.substring(root.length(), regex.length());
 521         }
 522       }
 523       @SuppressWarnings("unchecked")
 524       List<String> welcomeFiles =
 525           (List<String>) glob.getProperty(WELCOME_FILES, RESOLVER);
 526       if (welcomeFiles != null) {
 527         for (String welcomeFile : welcomeFiles) {
 528           builder.append("- url: (" + regex + ")\n");
 529           builder.append("  static_files: __static__" + root + "\\1" + welcomeFile + "\n");
 530           builder.append("  upload: __NOT_USED__\n");
 531           builder.append("  require_matching_file: True\n");
 532           translateHandlerOptions(builder, glob);
 533           translateAdditionalStaticOptions(builder, glob);
 534         }
 535       } else {
 536         Boolean isStatic = (Boolean) glob.getProperty(STATIC_PROPERTY, RESOLVER);
 537         if (isStatic != null && isStatic.booleanValue()) {
 538           builder.append("- url: (" + regex + ")\n");
 539           builder.append("  static_files: __static__" + root + "\\1\n");
 540           builder.append("  upload: __NOT_USED__\n");
 541           builder.append("  require_matching_file: True\n");
 542           translateHandlerOptions(builder, glob);
 543           translateAdditionalStaticOptions(builder, glob);
 544         }
 545       }
 546     }
 547
 548     private void translateAdditionalStaticOptions(StringBuilder builder, Glob glob)
 549         throws AppEngineConfigException {
 550       String expiration = (String) glob.getProperty(EXPIRATION_PROPERTY, RESOLVER);
 551       if (expiration != null) {
 552         builder.append("  expiration: " + expiration + "\n");
 553       }
 554
 555       @SuppressWarnings("unchecked")
 556       Map<String, String> httpHeaders =
 557           (Map<String, String>) glob.getProperty(HTTP_HEADERS_PROPERTY, RESOLVER);
 558       if (httpHeaders != null && !httpHeaders.isEmpty()) {
 559         builder.append("  http_headers:\n");
 560         appendObjectAsYaml(builder, httpHeaders, 4);
 561       }
 562     }
 563   }
 564
 565   /**
 566    * According to the example In section 12.2.2 of Servlet Spec 3.0 , /baz/* should also match /baz,
 567    * so add an additional glob for that.
 568    */
 569   private static void extendMeaningOfTrailingStar(
 570       GlobIntersector intersector, String pattern, String property, Object value) {
 571     if (pattern.endsWith("/*") && pattern.length() > 2) {
 572       intersector.addGlob(
 573           GlobFactory.createGlob(pattern.substring(0, pattern.length() - 2), property, value));
 574     }
 575   }
 576
 577   class DynamicHandlerGenerator extends AbstractHandlerGenerator {
 578     private final List<String> patterns;
 579     private boolean fallthrough;
 580     private boolean hasJsps;
 581
 582     DynamicHandlerGenerator(boolean alwaysFallthrough) {
 583       fallthrough = alwaysFallthrough;
 584       patterns = new ArrayList<String>();
 585       for (String servletPattern : webXml.getServletPatterns()) {
 586         if (servletPattern.equals("/") || servletPattern.equals("/*")) {
 587           fallthrough = true;
 588         } else if (servletPattern.equals(API_ENDPOINT_REGEX)) {
 589           hasApiEndpoint = true;
 590         } else if (servletPattern.endsWith(".jsp")) {
 591           hasJsps = true;
 592         } else {
 593           patterns.add(servletPattern);
 594         }
 595       }
 596     }
 597
 598     @Override
 599     protected Map<String, Object> getWelcomeProperties() {
 600       if (fallthrough) {
 601         return null;
 602       } else {
 603         return Collections.<String,Object>singletonMap(DYNAMIC_PROPERTY, true);
 604       }
 605     }
 606
 607     @Override
 608     protected void addPatterns(GlobIntersector intersector) {
 609       if (fallthrough) {
 610         intersector.addGlob(GlobFactory.createGlob(
 611             "/*",
 612             DYNAMIC_PROPERTY, true));
 613       } else {
 614         for (String servletPattern : patterns) {
 615           intersector.addGlob(GlobFactory.createGlob(
 616               servletPattern,
 617               DYNAMIC_PROPERTY, true));
 618           extendMeaningOfTrailingStar(intersector, servletPattern, DYNAMIC_PROPERTY, true);
 619         }
 620         if (hasJsps) {
 621           intersector.addGlob(GlobFactory.createGlob(
 622               "*.jsp",
 623               DYNAMIC_PROPERTY, true));
 624         } else if (appEngineWebXml.getUseVm() || appEngineWebXml.getEnv().equals("2")) {
 625           intersector.addGlob(GlobFactory.createGlob("*.jsp", DYNAMIC_PROPERTY, true));
 626         }
 627         intersector.addGlob(GlobFactory.createGlob(
 628             "/_ah/*",
 629             DYNAMIC_PROPERTY, true));
 630       }
 631     }
 632
 633     @Override
 634     public void translateGlob(StringBuilder builder, Glob glob) {
 635       String regex = glob.getRegularExpression().pattern();
 636
 637       Boolean isDynamic = (Boolean) glob.getProperty(DYNAMIC_PROPERTY, RESOLVER);
 638       if (isDynamic != null && isDynamic.booleanValue()) {
 639         builder.append("- url: " + regex + "\n");
 640         builder.append("  script: unused\n");
 641         translateHandlerOptions(builder, glob);
 642       }
 643     }
 644   }
 645
 646   /**
 647    * An {@code AbstractHandlerGenerator} that returns no globs.
 648    */
 649   class EmptyHandlerGenerator extends AbstractHandlerGenerator {
 650     @Override
 651     protected void addPatterns(GlobIntersector intersector) {
 652     }
 653
 654     @Override
 655     protected void translateGlob(StringBuilder builder, Glob glob) {
 656     }
 657
 658     @Override
 659     protected Map<String, Object> getWelcomeProperties() {
 660       return Collections.emptyMap();
 661     }
 662   }
 663
 664   abstract class AbstractHandlerGenerator {
 665     private List<Glob> globs = null;
 666     protected boolean hasApiEndpoint;
 667
 668     public int size() {
 669       return getGlobPatterns().size();
 670     }
 671
 672     public void translate(StringBuilder builder) {
 673       for (Glob glob : getGlobPatterns()) {
 674         translateGlob(builder, glob);
 675       }
 676     }
 677
 678     abstract protected void addPatterns(GlobIntersector intersector);
 679     abstract protected void translateGlob(StringBuilder builder, Glob glob);
 680
 681     /**
 682      * @returns a map of welcome properties to apply to the welcome
 683      * file entries, or {@code null} if no welcome file entries are
 684      * necessary.
 685      */
 686     abstract protected Map<String, Object> getWelcomeProperties();
 687
 688     protected List<Glob> getGlobPatterns() {
 689       if (globs == null) {
 690         GlobIntersector intersector = new GlobIntersector();
 691         addPatterns(intersector);
 692         addSecurityConstraints(intersector);
 693         addWelcomeFiles(intersector);
 694
 695         globs = intersector.getIntersection();
 696         removeNearDuplicates(globs);
 697         if (hasApiEndpoint) {
 698           globs.add(GlobFactory.createGlob(API_ENDPOINT_REGEX, DYNAMIC_PROPERTY, true));
 699         }
 700       }
 701       return globs;
 702     }
 703
 704     protected void addWelcomeFiles(GlobIntersector intersector) {
 705       Map<String, Object> welcomeProperties = getWelcomeProperties();
 706       if (welcomeProperties != null) {
 707         intersector.addGlob(GlobFactory.createGlob("/", welcomeProperties));
 708         intersector.addGlob(GlobFactory.createGlob("/*/", welcomeProperties));
 709       }
 710     }
 711
 712     protected void addSecurityConstraints(GlobIntersector intersector) {
 713       for (SecurityConstraint constraint : webXml.getSecurityConstraints()) {
 714         for (String pattern : constraint.getUrlPatterns()) {
 715           intersector.addGlob(GlobFactory.createGlob(
 716               pattern,
 717               TRANSPORT_GUARANTEE_PROPERTY,
 718               constraint.getTransportGuarantee()));
 719           extendMeaningOfTrailingStar(intersector, pattern, TRANSPORT_GUARANTEE_PROPERTY,
 720               constraint.getTransportGuarantee());
 721           intersector.addGlob(GlobFactory.createGlob(
 722               pattern,
 723               REQUIRED_ROLE_PROPERTY,
 724               constraint.getRequiredRole()));
 725           extendMeaningOfTrailingStar(
 726               intersector, pattern, REQUIRED_ROLE_PROPERTY, constraint.getRequiredRole());
 727         }
 728       }
 729     }
 730
 731     protected void translateHandlerOptions(StringBuilder builder, Glob glob) {
 732       SecurityConstraint.RequiredRole requiredRole =
 733           (SecurityConstraint.RequiredRole) glob.getProperty(REQUIRED_ROLE_PROPERTY, RESOLVER);
 734       if (requiredRole == null) {
 735         requiredRole = SecurityConstraint.RequiredRole.NONE;
 736       }
 737       switch (requiredRole) {
 738         case NONE:
 739           builder.append("  login: optional\n");
 740           break;
 741         case ANY_USER:
 742           builder.append("  login: required\n");
 743           break;
 744         case ADMIN:
 745           builder.append("  login: admin\n");
 746           break;
 747       }
 748
 749       SecurityConstraint.TransportGuarantee transportGuarantee =
 750           (SecurityConstraint.TransportGuarantee) glob.getProperty(TRANSPORT_GUARANTEE_PROPERTY,
 751                                                                    RESOLVER);
 752       if (transportGuarantee == null) {
 753         transportGuarantee = SecurityConstraint.TransportGuarantee.NONE;
 754       }
 755       switch (transportGuarantee) {
 756         case NONE:
 757           if (appEngineWebXml.getSslEnabled()) {
 758             builder.append("  secure: optional\n");
 759           } else {
 760             builder.append("  secure: never\n");
 761           }
 762           break;
 763         case INTEGRAL:
 764         case CONFIDENTIAL:
 765           if (!appEngineWebXml.getSslEnabled()) {
 766             throw new AppEngineConfigException(
 767                 "SSL must be enabled in appengine-web.xml to use transport-guarantee");
 768           }
 769           builder.append("  secure: always\n");
 770           break;
 771       }
 772
 773       String pattern = glob.getRegularExpression().pattern();
 774       String id = webXml.getHandlerIdForPattern(pattern);
 775       if (id != null) {
 776         if (appEngineWebXml.isApiEndpoint(id)) {
 777           builder.append("  api_endpoint: True\n");
 778         }
 779       }
 780     }
 781
 782     private void removeNearDuplicates(List<Glob> globs) {
 783       for (int i = 0; i < globs.size(); i++) {
 784         Glob topGlob = globs.get(i);
 785         for (int j = i + 1; j < globs.size(); j++) {
 786           Glob bottomGlob = globs.get(j);
 787           if (bottomGlob.matchesAll(topGlob)) {
 788             if (propertiesMatch(topGlob, bottomGlob)) {
 789               globs.remove(i);
 790               i--;
 791             }
 792             break;
 793           }
 794         }
 795       }
 796     }
 797
 798     private boolean propertiesMatch(Glob glob1, Glob glob2) {
 799       for (String property : PROPERTIES) {
 800         Object value1 = glob1.getProperty(property, RESOLVER);
 801         Object value2 = glob2.getProperty(property, RESOLVER);
 802         if (value1 != value2 && (value1 == null || !value1.equals(value2))) {
 803           return false;
 804         }
 805       }
 806       return true;
 807     }
 808   }
 809 }