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.getService() != null) {
 141       builder.append("module: '" + appEngineWebXml.getService() + "'\n");
 142     } else if (appEngineWebXml.getModule() != null) {
 143       builder.append("module: '" + appEngineWebXml.getModule() + "'\n");
 144     }
 145
 146     if (appEngineWebXml.getInstanceClass() != null) {
 147       builder.append("instance_class: " + appEngineWebXml.getInstanceClass() + "\n");
 148     }
 149
 150     if (!appEngineWebXml.getAutomaticScaling().isEmpty()) {
 151       builder.append("automatic_scaling:\n");
 152       AppEngineWebXml.AutomaticScaling settings = appEngineWebXml.getAutomaticScaling();
 153       appendIfNotNull(builder, "  min_pending_latency: ", settings.getMinPendingLatency());
 154       appendIfNotNull(builder, "  max_pending_latency: ", settings.getMaxPendingLatency());
 155       appendIfNotNull(builder, "  min_idle_instances: ", settings.getMinIdleInstances());
 156       appendIfNotNull(builder, "  max_idle_instances: ", settings.getMaxIdleInstances());
 157       appendIfNotNull(builder, "  max_concurrent_requests: ", settings.getMaxConcurrentRequests());
 158       appendIfNotNull(builder, "  min_num_instances: ", settings.getMinNumInstances());
 159       appendIfNotNull(builder, "  max_num_instances: ", settings.getMaxNumInstances());
 160       appendIfNotNull(builder, "  cool_down_period_sec: ", settings.getCoolDownPeriodSec());
 161
 162       CpuUtilization cpuUtil = settings.getCpuUtilization();
 163       if (cpuUtil != null
 164           && (cpuUtil.getTargetUtilization() != null
 165               || cpuUtil.getAggregationWindowLengthSec() != null)) {
 166         builder.append("  cpu_utilization:\n");
 167         appendIfNotNull(builder, "    target_utilization: ", cpuUtil.getTargetUtilization());
 168         appendIfNotNull(
 169             builder, "    aggregation_window_length_sec: ",
 170             cpuUtil.getAggregationWindowLengthSec());
 171       }
 172
 173       appendIfNotNull(
 174           builder, "  target_network_sent_bytes_per_sec: ",
 175           settings.getTargetNetworkSentBytesPerSec());
 176       appendIfNotNull(
 177           builder, "  target_network_sent_packets_per_sec: ",
 178           settings.getTargetNetworkSentPacketsPerSec());
 179       appendIfNotNull(
 180           builder, "  target_network_received_bytes_per_sec: ",
 181           settings.getTargetNetworkReceivedBytesPerSec());
 182       appendIfNotNull(
 183           builder, "  target_network_received_packets_per_sec: ",
 184           settings.getTargetNetworkReceivedPacketsPerSec());
 185       appendIfNotNull(
 186           builder, "  target_disk_write_bytes_per_sec: ",
 187           settings.getTargetDiskWriteBytesPerSec());
 188       appendIfNotNull(
 189           builder, "  target_disk_write_ops_per_sec: ",
 190           settings.getTargetDiskWriteOpsPerSec());
 191       appendIfNotNull(
 192           builder, "  target_disk_read_bytes_per_sec: ",
 193           settings.getTargetDiskReadBytesPerSec());
 194       appendIfNotNull(
 195           builder, "  target_disk_read_ops_per_sec: ",
 196           settings.getTargetDiskReadOpsPerSec());
 197       appendIfNotNull(
 198           builder, "  target_request_count_per_sec: ",
 199           settings.getTargetRequestCountPerSec());
 200       appendIfNotNull(
 201           builder, "  target_concurrent_requests: ",
 202           settings.getTargetConcurrentRequests());
 203     }
 204
 205     if (!appEngineWebXml.getManualScaling().isEmpty()) {
 206       builder.append("manual_scaling:\n");
 207       AppEngineWebXml.ManualScaling settings = appEngineWebXml.getManualScaling();
 208       builder.append("  instances: " + settings.getInstances() + "\n");
 209     }
 210
 211     if (!appEngineWebXml.getBasicScaling().isEmpty()) {
 212       builder.append("basic_scaling:\n");
 213       AppEngineWebXml.BasicScaling settings = appEngineWebXml.getBasicScaling();
 214       builder.append("  max_instances: " + settings.getMaxInstances() + "\n");
 215       appendIfNotNull(builder, "  idle_timeout: ", settings.getIdleTimeout());
 216     }
 217
 218     Collection<String> services = appEngineWebXml.getInboundServices();
 219     if (!services.isEmpty()) {
 220       builder.append("inbound_services:\n");
 221       for (String service : services) {
 222         builder.append("- " + service + "\n");
 223       }
 224     }
 225
 226     if (appEngineWebXml.getPrecompilationEnabled()) {
 227       builder.append("derived_file_type:\n");
 228       builder.append("- java_precompiled\n");
 229     }
 230
 231     if (appEngineWebXml.getThreadsafe()) {
 232       builder.append("threadsafe: True\n");
 233     }
 234
 235     if (appEngineWebXml.getAutoIdPolicy() != null) {
 236       builder.append("auto_id_policy: " + appEngineWebXml.getAutoIdPolicy() + "\n");
 237     } else {
 238       builder.append("auto_id_policy: default\n");
 239     }
 240
 241     if (appEngineWebXml.getCodeLock()) {
 242       builder.append("code_lock: True\n");
 243     }
 244
 245     List<AdminConsolePage> adminConsolePages = appEngineWebXml.getAdminConsolePages();
 246     if (!adminConsolePages.isEmpty()) {
 247       builder.append("admin_console:\n");
 248       builder.append("  pages:\n");
 249       for (AdminConsolePage page : adminConsolePages) {
 250         builder.append("  - name: " + page.getName() + "\n");
 251         builder.append("    url: " + page.getUrl() + "\n");
 252       }
 253     }
 254
 255     List<ErrorHandler> errorHandlers = appEngineWebXml.getErrorHandlers();
 256     if (!errorHandlers.isEmpty()) {
 257       builder.append("error_handlers:\n");
 258       for (ErrorHandler handler : errorHandlers) {
 259         String fileName = handler.getFile();
 260         if (!fileName.startsWith("/")) {
 261           fileName = "/" + fileName;
 262         }
 263         if (!staticFiles.contains("__static__" + fileName)) {
 264           throw new AppEngineConfigException("No static file found for error handler: "
 265               + fileName + ", out of " + staticFiles);
 266         }
 267         builder.append("- file: __static__" + fileName + "\n");
 268         if (handler.getErrorCode() != null) {
 269           builder.append("  error_code: " + handler.getErrorCode() + "\n");
 270         }
 271         String mimeType = webXml.getMimeTypeForPath(handler.getFile());
 272         if (mimeType != null) {
 273           builder.append("  mime_type: " + mimeType + "\n");
 274         }
 275       }
 276     }
 277
 278     if (backendsXml != null) {
 279       builder.append(backendsXml.toYaml());
 280     }
 281
 282     ApiConfig apiConfig = appEngineWebXml.getApiConfig();
 283     if (apiConfig != null) {
 284       builder.append("api_config:\n");
 285       builder.append("  url: " + apiConfig.getUrl() + "\n");
 286       builder.append("  script: unused\n");
 287     }
 288
 289     if (appEngineWebXml.getPagespeed() != null) {
 290       builder.append("pagespeed:\n");
 291       appendPagespeed(appEngineWebXml.getPagespeed(), builder, 2);
 292     }
 293
 294     if (appEngineWebXml.getUseVm() || appEngineWebXml.getEnv().equals("2")) {
 295       appendEnvVariables(appEngineWebXml.getEnvironmentVariables(), builder);
 296       appendBetaSettings(appEngineWebXml.getBetaSettings(), builder);
 297       appendHealthCheck(appEngineWebXml.getHealthCheck(), builder);
 298       appendResources(appEngineWebXml.getResources(), builder);
 299       appendNetwork(appEngineWebXml.getNetwork(), builder);
 300     }
 301   }
 302
 303   /**
 304    * Appends the given environment variables as YAML to the given StringBuilder.
 305    *
 306    * @param envVariables The env variables map to append as YAML.
 307    * @param builder The StringBuilder to append to.
 308    */
 309   private void appendEnvVariables(Map<String, String> envVariables, StringBuilder builder) {
 310     if (envVariables.size() > 0) {
 311       builder.append("env_variables:\n");
 312       for (Map.Entry<String, String> envVariable : envVariables.entrySet()) {
 313         String k = envVariable.getKey();
 314         String v = envVariable.getValue();
 315         builder.append("  ").append(yamlQuote(k)).append(": ").append(yamlQuote(v)).append("\n");
 316       }
 317     }
 318   }
 319
 320   /**
 321    * Appends the given Beta Settings as YAML to the given StringBuilder.
 322    *
 323    * @param betaSettings The beta settings map to append as YAML.
 324    * @param builder The StringBuilder to append to.
 325    */
 326   private void appendBetaSettings(Map<String, String> betaSettings, StringBuilder builder) {
 327     if (betaSettings != null && !betaSettings.isEmpty()) {
 328       builder.append("beta_settings:\n");
 329       for (Map.Entry<String, String> setting : betaSettings.entrySet()) {
 330         builder.append(
 331             "  " + yamlQuote(setting.getKey()) + ": " + yamlQuote(setting.getValue()) + "\n");
 332       }
 333     }
 334   }
 335
 336   private void appendHealthCheck(HealthCheck healthCheck, StringBuilder builder) {
 337     builder.append("health_check:\n");
 338     if (healthCheck.getEnableHealthCheck()) {
 339       builder.append("  enable_health_check: True\n");
 340     } else {
 341       builder.append("  enable_health_check: False\n");
 342     }
 343
 344     appendIfNotNull(builder, "  check_interval_sec: ", healthCheck.getCheckIntervalSec());
 345     appendIfNotNull(builder, "  timeout_sec: ", healthCheck.getTimeoutSec());
 346     appendIfNotNull(builder, "  unhealthy_threshold: ", healthCheck.getUnhealthyThreshold());
 347     appendIfNotNull(builder, "  healthy_threshold: ", healthCheck.getHealthyThreshold());
 348     appendIfNotNull(builder, "  restart_threshold: ", healthCheck.getRestartThreshold());
 349     appendIfNotNull(builder, "  host: ", healthCheck.getHost());
 350   }
 351
 352   private void appendResources(Resources resources, StringBuilder builder) {
 353     if (!resources.isEmpty()) {
 354       builder.append("resources:\n");
 355       appendIfNotZero(builder, "  cpu: ", resources.getCpu());
 356       appendIfNotZero(builder, "  memory_gb: ", resources.getMemoryGb());
 357       appendIfNotZero(builder, "  disk_size_gb: ", resources.getDiskSizeGb());
 358     }
 359   }
 360
 361   private void appendNetwork(Network network, StringBuilder builder) {
 362     if (!network.isEmpty()) {
 363       builder.append("network:\n");
 364       appendIfNotNull(builder, "  instance_tag: ", network.getInstanceTag());
 365       if (!network.getForwardedPorts().isEmpty()) {
 366         builder.append("  forwarded_ports:\n");
 367         for (String forwardedPort : network.getForwardedPorts()) {
 368           builder.append("  - " + forwardedPort + "\n");
 369         }
 370       }
 371       appendIfNotNull(builder, "  name: ", network.getName());
 372     }
 373   }
 374
 375   /**
 376    * Append the given Pagespeed node as YAML to the given StringBuilder.
 377    * @param pagespeed The Pagespeed instance to append as YAML.
 378    * @param builder The StringBuilder to append to.
 379    * @param indent The number of spaces to indent the pagespeed YAML.
 380    */
 381   public static void appendPagespeed(Pagespeed pagespeed, StringBuilder builder, int indent) {
 382     if (pagespeed != null && !pagespeed.isEmpty()) {
 383       Map<String, List<String>> config = Maps.newTreeMap();
 384       putListInMapIfNotEmpty(config, "url_blacklist", pagespeed.getUrlBlacklist());
 385       putListInMapIfNotEmpty(config, "domains_to_rewrite", pagespeed.getDomainsToRewrite());
 386       putListInMapIfNotEmpty(config, "enabled_rewriters", pagespeed.getEnabledRewriters());
 387       putListInMapIfNotEmpty(config, "disabled_rewriters", pagespeed.getDisabledRewriters());
 388       appendObjectAsYaml(builder, config, indent);
 389     }
 390   }
 391
 392   /**
 393    * Adds the list to the given map, using the specified name, if the list is non-null and not
 394    * empty.
 395    */
 396   private static void putListInMapIfNotEmpty(Map<String, List<String>> map, String name,
 397       List<String> values) {
 398     if (values != null && !values.isEmpty()) {
 399       map.put(name, values);
 400     }
 401   }
 402
 403   /**
 404    * Appends the given collection to the StringBuilder as YAML, indenting each emitted line by
 405    * numIndentSpaces.
 406    */
 407   private static void appendObjectAsYaml(
 408       StringBuilder builder, Object collection, int numIndentSpaces) {
 409     StringBuilder prefixBuilder = new StringBuilder();
 410     for (int i = 0; i < numIndentSpaces; ++i) {
 411       prefixBuilder.append(' ');
 412     }
 413     final String indentPrefix = prefixBuilder.toString();
 414
 415     StringWriter stringWriter = new StringWriter();
 416     YamlConfig yamlConfig = new YamlConfig();
 417     yamlConfig.writeConfig.setIndentSize(2);
 418     yamlConfig.writeConfig.setWriteRootTags(false);
 419
 420     YamlWriter writer = new YamlWriter(stringWriter, yamlConfig);
 421     try {
 422       writer.write(collection);
 423       writer.close();
 424     } catch (YamlException e) {
 425       throw new AppEngineConfigException("Unable to generate YAML.", e);
 426     }
 427
 428     for (String line : stringWriter.toString().split("\n")) {
 429       builder.append(indentPrefix);
 430       builder.append(line);
 431       builder.append("\n");
 432     }
 433   }
 434
 435   /**
 436    * Surrounds the provided string with single quotes, escaping any single
 437    * quotes in the string by replacing them with ''.
 438    */
 439   private String yamlQuote(String str) {
 440     return "'" + str.replace("'", "''") + "'";
 441   }
 442
 443   private void translateApiVersion(StringBuilder builder) {
 444     if (apiVersion == null) {
 445       builder.append("api_version: '" + NO_API_VERSION + "'\n");
 446     } else {
 447       builder.append("api_version: '" + apiVersion + "'\n");
 448     }
 449   }
 450
 451   private void translateWebXml(StringBuilder builder) {
 452     builder.append("handlers:\n");
 453
 454     AbstractHandlerGenerator staticGenerator = null;
 455     if (staticFiles.isEmpty()) {
 456       staticGenerator = new EmptyHandlerGenerator();
 457     } else {
 458       staticGenerator = new StaticHandlerGenerator(appEngineWebXml.getPublicRoot());
 459     }
 460
 461     DynamicHandlerGenerator dynamicGenerator =
 462         new DynamicHandlerGenerator(webXml.getFallThroughToRuntime());
 463     if (staticGenerator.size() + dynamicGenerator.size() > MAX_HANDLERS) {
 464       dynamicGenerator = new DynamicHandlerGenerator(true);
 465     }
 466
 467     staticGenerator.translate(builder);
 468     dynamicGenerator.translate(builder);
 469   }
 470
 471   class StaticHandlerGenerator extends AbstractHandlerGenerator {
 472     private final String root;
 473
 474     public StaticHandlerGenerator(String root) {
 475       this.root = root;
 476     }
 477
 478     @Override
 479     protected Map<String, Object> getWelcomeProperties() {
 480       List<String> staticWelcomeFiles = new ArrayList<String>();
 481       for (String welcomeFile : webXml.getWelcomeFiles()) {
 482         for (String staticFile : staticFiles) {
 483           if (staticFile.endsWith("/" + welcomeFile)) {
 484             staticWelcomeFiles.add(welcomeFile);
 485             break;
 486           }
 487         }
 488       }
 489       return Collections.<String,Object>singletonMap(WELCOME_FILES, staticWelcomeFiles);
 490     }
 491
 492     @Override
 493     protected void addPatterns(GlobIntersector intersector) {
 494       List<AppEngineWebXml.StaticFileInclude> includes = appEngineWebXml.getStaticFileIncludes();
 495       if (includes.isEmpty()) {
 496         intersector.addGlob(GlobFactory.createGlob("/*", STATIC_PROPERTY, true));
 497       } else {
 498         for (AppEngineWebXml.StaticFileInclude include : includes) {
 499           String pattern = include.getPattern().replaceAll("\\*\\*", "*");
 500           if (!pattern.startsWith("/")) {
 501             pattern = "/" + pattern;
 502           }
 503           Map<String, Object> props = new HashMap<String, Object>();
 504           props.put(STATIC_PROPERTY, true);
 505           if (include.getExpiration() != null) {
 506             props.put(EXPIRATION_PROPERTY, include.getExpiration());
 507           }
 508           if (include.getHttpHeaders() != null) {
 509             props.put(HTTP_HEADERS_PROPERTY, include.getHttpHeaders());
 510           }
 511
 512           intersector.addGlob(GlobFactory.createGlob(pattern, props));
 513         }
 514       }
 515     }
 516
 517     @Override
 518     public void translateGlob(StringBuilder builder, Glob glob) {
 519       String regex = glob.getRegularExpression().pattern();
 520       if (!root.isEmpty()) {
 521         if (regex.startsWith(root)){
 522           regex = regex.substring(root.length(), regex.length());
 523         }
 524       }
 525       @SuppressWarnings("unchecked")
 526       List<String> welcomeFiles =
 527           (List<String>) glob.getProperty(WELCOME_FILES, RESOLVER);
 528       if (welcomeFiles != null) {
 529         for (String welcomeFile : welcomeFiles) {
 530           builder.append("- url: (" + regex + ")\n");
 531           builder.append("  static_files: __static__" + root + "\\1" + welcomeFile + "\n");
 532           builder.append("  upload: __NOT_USED__\n");
 533           builder.append("  require_matching_file: True\n");
 534           translateHandlerOptions(builder, glob);
 535           translateAdditionalStaticOptions(builder, glob);
 536         }
 537       } else {
 538         Boolean isStatic = (Boolean) glob.getProperty(STATIC_PROPERTY, RESOLVER);
 539         if (isStatic != null && isStatic.booleanValue()) {
 540           builder.append("- url: (" + regex + ")\n");
 541           builder.append("  static_files: __static__" + root + "\\1\n");
 542           builder.append("  upload: __NOT_USED__\n");
 543           builder.append("  require_matching_file: True\n");
 544           translateHandlerOptions(builder, glob);
 545           translateAdditionalStaticOptions(builder, glob);
 546         }
 547       }
 548     }
 549
 550     private void translateAdditionalStaticOptions(StringBuilder builder, Glob glob)
 551         throws AppEngineConfigException {
 552       String expiration = (String) glob.getProperty(EXPIRATION_PROPERTY, RESOLVER);
 553       if (expiration != null) {
 554         builder.append("  expiration: " + expiration + "\n");
 555       }
 556
 557       @SuppressWarnings("unchecked")
 558       Map<String, String> httpHeaders =
 559           (Map<String, String>) glob.getProperty(HTTP_HEADERS_PROPERTY, RESOLVER);
 560       if (httpHeaders != null && !httpHeaders.isEmpty()) {
 561         builder.append("  http_headers:\n");
 562         appendObjectAsYaml(builder, httpHeaders, 4);
 563       }
 564     }
 565   }
 566
 567   /**
 568    * According to the example In section 12.2.2 of Servlet Spec 3.0 , /baz/* should also match /baz,
 569    * so add an additional glob for that.
 570    */
 571   private static void extendMeaningOfTrailingStar(
 572       GlobIntersector intersector, String pattern, String property, Object value) {
 573     if (pattern.endsWith("/*") && pattern.length() > 2) {
 574       intersector.addGlob(
 575           GlobFactory.createGlob(pattern.substring(0, pattern.length() - 2), property, value));
 576     }
 577   }
 578
 579   class DynamicHandlerGenerator extends AbstractHandlerGenerator {
 580     private final List<String> patterns;
 581     private boolean fallthrough;
 582     private boolean hasJsps;
 583
 584     DynamicHandlerGenerator(boolean alwaysFallthrough) {
 585       fallthrough = alwaysFallthrough;
 586       patterns = new ArrayList<String>();
 587       for (String servletPattern : webXml.getServletPatterns()) {
 588         if (servletPattern.equals("/") || servletPattern.equals("/*")) {
 589           fallthrough = true;
 590         } else if (servletPattern.equals(API_ENDPOINT_REGEX)) {
 591           hasApiEndpoint = true;
 592         } else if (servletPattern.endsWith(".jsp")) {
 593           hasJsps = true;
 594         } else {
 595           patterns.add(servletPattern);
 596         }
 597       }
 598     }
 599
 600     @Override
 601     protected Map<String, Object> getWelcomeProperties() {
 602       if (fallthrough) {
 603         return null;
 604       } else {
 605         return Collections.<String,Object>singletonMap(DYNAMIC_PROPERTY, true);
 606       }
 607     }
 608
 609     @Override
 610     protected void addPatterns(GlobIntersector intersector) {
 611       if (fallthrough) {
 612         intersector.addGlob(GlobFactory.createGlob(
 613             "/*",
 614             DYNAMIC_PROPERTY, true));
 615       } else {
 616         for (String servletPattern : patterns) {
 617           intersector.addGlob(GlobFactory.createGlob(
 618               servletPattern,
 619               DYNAMIC_PROPERTY, true));
 620           extendMeaningOfTrailingStar(intersector, servletPattern, DYNAMIC_PROPERTY, true);
 621         }
 622         if (hasJsps) {
 623           intersector.addGlob(GlobFactory.createGlob(
 624               "*.jsp",
 625               DYNAMIC_PROPERTY, true));
 626         } else if (appEngineWebXml.getUseVm() || appEngineWebXml.getEnv().equals("2")) {
 627           intersector.addGlob(GlobFactory.createGlob("*.jsp", DYNAMIC_PROPERTY, true));
 628         }
 629         intersector.addGlob(GlobFactory.createGlob(
 630             "/_ah/*",
 631             DYNAMIC_PROPERTY, true));
 632       }
 633     }
 634
 635     @Override
 636     public void translateGlob(StringBuilder builder, Glob glob) {
 637       String regex = glob.getRegularExpression().pattern();
 638
 639       Boolean isDynamic = (Boolean) glob.getProperty(DYNAMIC_PROPERTY, RESOLVER);
 640       if (isDynamic != null && isDynamic.booleanValue()) {
 641         builder.append("- url: " + regex + "\n");
 642         builder.append("  script: unused\n");
 643         translateHandlerOptions(builder, glob);
 644       }
 645     }
 646   }
 647
 648   /**
 649    * An {@code AbstractHandlerGenerator} that returns no globs.
 650    */
 651   class EmptyHandlerGenerator extends AbstractHandlerGenerator {
 652     @Override
 653     protected void addPatterns(GlobIntersector intersector) {
 654     }
 655
 656     @Override
 657     protected void translateGlob(StringBuilder builder, Glob glob) {
 658     }
 659
 660     @Override
 661     protected Map<String, Object> getWelcomeProperties() {
 662       return Collections.emptyMap();
 663     }
 664   }
 665
 666   abstract class AbstractHandlerGenerator {
 667     private List<Glob> globs = null;
 668     protected boolean hasApiEndpoint;
 669
 670     public int size() {
 671       return getGlobPatterns().size();
 672     }
 673
 674     public void translate(StringBuilder builder) {
 675       for (Glob glob : getGlobPatterns()) {
 676         translateGlob(builder, glob);
 677       }
 678     }
 679
 680     abstract protected void addPatterns(GlobIntersector intersector);
 681     abstract protected void translateGlob(StringBuilder builder, Glob glob);
 682
 683     /**
 684      * @returns a map of welcome properties to apply to the welcome
 685      * file entries, or {@code null} if no welcome file entries are
 686      * necessary.
 687      */
 688     abstract protected Map<String, Object> getWelcomeProperties();
 689
 690     protected List<Glob> getGlobPatterns() {
 691       if (globs == null) {
 692         GlobIntersector intersector = new GlobIntersector();
 693         addPatterns(intersector);
 694         addSecurityConstraints(intersector);
 695         addWelcomeFiles(intersector);
 696
 697         globs = intersector.getIntersection();
 698         removeNearDuplicates(globs);
 699         if (hasApiEndpoint) {
 700           globs.add(GlobFactory.createGlob(API_ENDPOINT_REGEX, DYNAMIC_PROPERTY, true));
 701         }
 702       }
 703       return globs;
 704     }
 705
 706     protected void addWelcomeFiles(GlobIntersector intersector) {
 707       Map<String, Object> welcomeProperties = getWelcomeProperties();
 708       if (welcomeProperties != null) {
 709         intersector.addGlob(GlobFactory.createGlob("/", welcomeProperties));
 710         intersector.addGlob(GlobFactory.createGlob("/*/", welcomeProperties));
 711       }
 712     }
 713
 714     protected void addSecurityConstraints(GlobIntersector intersector) {
 715       for (SecurityConstraint constraint : webXml.getSecurityConstraints()) {
 716         for (String pattern : constraint.getUrlPatterns()) {
 717           intersector.addGlob(GlobFactory.createGlob(
 718               pattern,
 719               TRANSPORT_GUARANTEE_PROPERTY,
 720               constraint.getTransportGuarantee()));
 721           extendMeaningOfTrailingStar(intersector, pattern, TRANSPORT_GUARANTEE_PROPERTY,
 722               constraint.getTransportGuarantee());
 723           intersector.addGlob(GlobFactory.createGlob(
 724               pattern,
 725               REQUIRED_ROLE_PROPERTY,
 726               constraint.getRequiredRole()));
 727           extendMeaningOfTrailingStar(
 728               intersector, pattern, REQUIRED_ROLE_PROPERTY, constraint.getRequiredRole());
 729         }
 730       }
 731     }
 732
 733     protected void translateHandlerOptions(StringBuilder builder, Glob glob) {
 734       SecurityConstraint.RequiredRole requiredRole =
 735           (SecurityConstraint.RequiredRole) glob.getProperty(REQUIRED_ROLE_PROPERTY, RESOLVER);
 736       if (requiredRole == null) {
 737         requiredRole = SecurityConstraint.RequiredRole.NONE;
 738       }
 739       switch (requiredRole) {
 740         case NONE:
 741           builder.append("  login: optional\n");
 742           break;
 743         case ANY_USER:
 744           builder.append("  login: required\n");
 745           break;
 746         case ADMIN:
 747           builder.append("  login: admin\n");
 748           break;
 749       }
 750
 751       SecurityConstraint.TransportGuarantee transportGuarantee =
 752           (SecurityConstraint.TransportGuarantee) glob.getProperty(TRANSPORT_GUARANTEE_PROPERTY,
 753                                                                    RESOLVER);
 754       if (transportGuarantee == null) {
 755         transportGuarantee = SecurityConstraint.TransportGuarantee.NONE;
 756       }
 757       switch (transportGuarantee) {
 758         case NONE:
 759           if (appEngineWebXml.getSslEnabled()) {
 760             builder.append("  secure: optional\n");
 761           } else {
 762             builder.append("  secure: never\n");
 763           }
 764           break;
 765         case INTEGRAL:
 766         case CONFIDENTIAL:
 767           if (!appEngineWebXml.getSslEnabled()) {
 768             throw new AppEngineConfigException(
 769                 "SSL must be enabled in appengine-web.xml to use transport-guarantee");
 770           }
 771           builder.append("  secure: always\n");
 772           break;
 773       }
 774
 775       String pattern = glob.getRegularExpression().pattern();
 776       String id = webXml.getHandlerIdForPattern(pattern);
 777       if (id != null) {
 778         if (appEngineWebXml.isApiEndpoint(id)) {
 779           builder.append("  api_endpoint: True\n");
 780         }
 781       }
 782     }
 783
 784     private void removeNearDuplicates(List<Glob> globs) {
 785       for (int i = 0; i < globs.size(); i++) {
 786         Glob topGlob = globs.get(i);
 787         for (int j = i + 1; j < globs.size(); j++) {
 788           Glob bottomGlob = globs.get(j);
 789           if (bottomGlob.matchesAll(topGlob)) {
 790             if (propertiesMatch(topGlob, bottomGlob)) {
 791               globs.remove(i);
 792               i--;
 793             }
 794             break;
 795           }
 796         }
 797       }
 798     }
 799
 800     private boolean propertiesMatch(Glob glob1, Glob glob2) {
 801       for (String property : PROPERTIES) {
 802         Object value1 = glob1.getProperty(property, RESOLVER);
 803         Object value2 = glob2.getProperty(property, RESOLVER);
 804         if (value1 != value2 && (value1 == null || !value1.equals(value2))) {
 805           return false;
 806         }
 807       }
 808       return true;
 809     }
 810   }
 811 }