【ShenYu系列】ShenYu Dubbo插件全流程源码解析

网关启动

在ShenyuConfiguration注入ShenyuWebHandler。

    @Bean("webHandler")public ShenyuWebHandler shenyuWebHandler(final ObjectProvider<List<ShenyuPlugin>> plugins, final ShenyuConfig config, @Lazy final ShenyuLoaderService shenyuLoaderService) {List<ShenyuPlugin> pluginList = plugins.getIfAvailable(Collections::emptyList);List<ShenyuPlugin> shenyuPlugins = pluginList.stream().sorted(Comparator.comparingInt(ShenyuPlugin::getOrder)).collect(Collectors.toList());shenyuPlugins.forEach(shenyuPlugin -> LOG.info("load plugin:[{}] [{}]", shenyuPlugin.named(), shenyuPlugin.getClass().getName()));return new ShenyuWebHandler(shenyuPlugins, shenyuLoaderService, config);}

在NacosSyncDataConfiguration注入用nacos的数据同步服务。

    @Beanpublic SyncDataService nacosSyncDataService(final ObjectProvider<ConfigService> configService, final ObjectProvider<PluginDataSubscriber> pluginSubscriber,final ObjectProvider<List<MetaDataSubscriber>> metaSubscribers, final ObjectProvider<List<AuthDataSubscriber>> authSubscribers) {LOGGER.info("you use nacos sync shenyu data.......");return new NacosSyncDataService(configService.getIfAvailable(), pluginSubscriber.getIfAvailable(),metaSubscribers.getIfAvailable(Collections::emptyList), authSubscribers.getIfAvailable(Collections::emptyList));}

该实例的构造方法中会执行NacosSyncDataService#start

    public void start() {watcherData(NacosPathConstants.PLUGIN_DATA_ID, this::updatePluginMap);watcherData(NacosPathConstants.SELECTOR_DATA_ID, this::updateSelectorMap);watcherData(NacosPathConstants.RULE_DATA_ID, this::updateRuleMap);watcherData(NacosPathConstants.META_DATA_ID, this::updateMetaDataMap);watcherData(NacosPathConstants.AUTH_DATA_ID, this::updateAuthMap);}

NacosCacheHandler#updatePluginMap，监听到数据，执行

    protected void updatePluginMap(final String configInfo) {try {// Fix bug #656(https://github.com/apache/shenyu/issues/656)List<PluginData> pluginDataList = new ArrayList<>(GsonUtils.getInstance().toObjectMap(configInfo, PluginData.class).values());pluginDataList.forEach(pluginData -> Optional.ofNullable(pluginDataSubscriber).ifPresent(subscriber -> {subscriber.unSubscribe(pluginData);subscriber.onSubscribe(pluginData);}));} catch (JsonParseException e) {LOG.error("sync plugin data have error:", e);}}

AbstractDubboPluginDataHandler#handlerPlugin，处理器，把数据存储到ApacheDubboConfigCache

public abstract class AbstractDubboPluginDataHandler implements PluginDataHandler {public static final Supplier<CommonHandleCache<String, DubboRuleHandle>> RULE_CACHED_HANDLE = new BeanHolder<>(CommonHandleCache::new);public static final Supplier<CommonHandleCache<String, List<DubboUpstream>>> SELECTOR_CACHED_HANDLE = new BeanHolder<>(CommonHandleCache::new);protected abstract void initConfigCache(DubboRegisterConfig dubboRegisterConfig);@Overridepublic void handlerPlugin(final PluginData pluginData) {if (Objects.nonNull(pluginData) && Boolean.TRUE.equals(pluginData.getEnabled())) {DubboRegisterConfig dubboRegisterConfig = GsonUtils.getInstance().fromJson(pluginData.getConfig(), DubboRegisterConfig.class);DubboRegisterConfig exist = Singleton.INST.get(DubboRegisterConfig.class);if (Objects.isNull(dubboRegisterConfig)) {return;}if (Objects.isNull(exist) || !dubboRegisterConfig.equals(exist)) {// If it is null, initialize itthis.initConfigCache(dubboRegisterConfig);}Singleton.INST.single(DubboRegisterConfig.class, dubboRegisterConfig);}}
}

ApacheDubboPluginDataHandler

public class ApacheDubboPluginDataHandler extends AbstractDubboPluginDataHandler {@Overrideprotected void initConfigCache(final DubboRegisterConfig dubboRegisterConfig) {ApacheDubboConfigCache.getInstance().init(dubboRegisterConfig);ApacheDubboConfigCache.getInstance().invalidateAll();}
}

服务调用

ShenyuWebHandler.DefaultShenyuPluginChain#execute，执行每个插件.。

        @Overridepublic Mono<Void> execute(final ServerWebExchange exchange) {return Mono.defer(() -> {if (this.index < plugins.size()) {ShenyuPlugin plugin = plugins.get(this.index++);boolean skip = plugin.skip(exchange);if (skip) {return this.execute(exchange);}return plugin.execute(exchange, this);}return Mono.empty();});}

AbstractShenyuPlugin#execute，匹配选择器和插件。

    public Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {initCacheConfig();final String pluginName = named();PluginData pluginData = BaseDataCache.getInstance().obtainPluginData(pluginName);// early exitif (Objects.isNull(pluginData) || !pluginData.getEnabled()) {return chain.execute(exchange);}final String path = exchange.getRequest().getURI().getPath();List<SelectorData> selectors = BaseDataCache.getInstance().obtainSelectorData(pluginName);SelectorData selectorData = obtainSelectorDataCacheIfEnabled(path);// handle Selectorif (Objects.nonNull(selectorData) && StringUtils.isBlank(selectorData.getId())) {return handleSelectorIfNull(pluginName, exchange, chain);}if (Objects.isNull(selectorData)) {if (CollectionUtils.isEmpty(selectors)) {return handleSelectorIfNull(pluginName, exchange, chain);}Pair<Boolean, SelectorData> matchSelectorData = matchSelector(exchange, selectors);selectorData = matchSelectorData.getRight();if (Objects.isNull(selectorData)) {if (matchCacheConfig.getSelector().getSelectorEnabled() && matchSelectorData.getLeft()) {selectorData = new SelectorData();selectorData.setPluginName(pluginName);cacheSelectorData(path, selectorData);}return handleSelectorIfNull(pluginName, exchange, chain);} else {if (matchCacheConfig.getSelector().getSelectorEnabled() && matchSelectorData.getLeft()) {cacheSelectorData(path, selectorData);}}}printLog(selectorData, pluginName);if (Objects.nonNull(selectorData.getContinued()) && !selectorData.getContinued()) {// if continued， not match rulesreturn doExecute(exchange, chain, selectorData, defaultRuleData(selectorData));}List<RuleData> rules = BaseDataCache.getInstance().obtainRuleData(selectorData.getId());if (CollectionUtils.isEmpty(rules)) {return handleRuleIfNull(pluginName, exchange, chain);}RuleData ruleData = obtainRuleDataCache(path);if (Objects.nonNull(ruleData) && Objects.isNull(ruleData.getId())) {return handleRuleIfNull(pluginName, exchange, chain);}if (selectorData.getType() == SelectorTypeEnum.FULL_FLOW.getCode()) {//get lastRuleData rule = rules.get(rules.size() - 1);printLog(rule, pluginName);return doExecute(exchange, chain, selectorData, rule);} else {// lru map as L1 cache,the cache is enabled by default.// if the L1 cache fails to hit, using L2 cache based on trie cache.// if the L2 cache fails to hit, execute default strategy.if (Objects.isNull(ruleData)) {// L1 cache not exist data, try to get data through trie cacheruleData = trieMatchRule(exchange, selectorData, path);// trie cache fails to hit, execute default strategyif (Objects.isNull(ruleData)) {LOG.info("{} rule match path from default strategy", named());Pair<Boolean, RuleData> matchRuleData = matchRule(exchange, rules);ruleData = matchRuleData.getRight();if (matchRuleData.getLeft()) {ruleData = Optional.ofNullable(ruleData).orElse(RuleData.builder().pluginName(pluginName).matchRestful(false).build());cacheRuleData(path, ruleData);}}}}if (Objects.isNull(ruleData) || Objects.isNull(ruleData.getId())) {return handleRuleIfNull(pluginName, exchange, chain);}printLog(ruleData, pluginName);return doExecute(exchange, chain, selectorData, ruleData);}

GlobalPlugin构建上下文信息

public class GlobalPlugin implements ShenyuPlugin {private final ShenyuContextBuilder builder;/*** Instantiates a new Global plugin.** @param builder the builder*/public GlobalPlugin(final ShenyuContextBuilder builder) {this.builder = builder;}@Overridepublic Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {ShenyuContext shenyuContext = builder.build(exchange);exchange.getAttributes().put(Constants.CONTEXT, shenyuContext);return chain.execute(exchange);}
}

DefaultShenyuContextBuilder#build，构建上下文

    @Overridepublic ShenyuContext build(final ServerWebExchange exchange) {Pair<String, MetaData> buildData = buildData(exchange);return decoratorMap.get(buildData.getLeft()).decorator(buildDefaultContext(exchange.getRequest()), buildData.getRight());}private Pair<String, MetaData> buildData(final ServerWebExchange exchange) {ServerHttpRequest request = exchange.getRequest();HttpHeaders headers = request.getHeaders();String rpcType = headers.getFirst(RPC_TYPE);if (StringUtils.isNotEmpty(rpcType)) {return Pair.of(rpcType, new MetaData());}String upgrade = headers.getFirst(UPGRADE);if (StringUtils.isNotEmpty(upgrade) && RpcTypeEnum.WEB_SOCKET.getName().equals(upgrade)) {return Pair.of(RpcTypeEnum.WEB_SOCKET.getName(), new MetaData());}MetaData metaData = MetaDataCache.getInstance().obtain(request.getURI().getPath());if (Objects.nonNull(metaData) && Boolean.TRUE.equals(metaData.getEnabled())) {exchange.getAttributes().put(Constants.META_DATA, metaData);return Pair.of(metaData.getRpcType(), metaData);} else {return Pair.of(RpcTypeEnum.HTTP.getName(), new MetaData());}}

RpcParamTransformPlugin用于获取参数信息

public class RpcParamTransformPlugin implements ShenyuPlugin {@Overridepublic Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {ServerHttpRequest request = exchange.getRequest();ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);if (Objects.nonNull(shenyuContext)) {MediaType mediaType = request.getHeaders().getContentType();if (MediaType.APPLICATION_JSON.isCompatibleWith(mediaType)) {return body(exchange, request, chain);}if (MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(mediaType)) {return formData(exchange, request, chain);}return query(exchange, request, chain);}return chain.execute(exchange);}
}

AbstractDubboPlugin#doExecute，检查元数据和参数，进行方法调用

    @Overridepublic Mono<Void> doExecute(final ServerWebExchange exchange,final ShenyuPluginChain chain,final SelectorData selector,final RuleData rule) {String param = exchange.getAttribute(Constants.PARAM_TRANSFORM);ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);assert shenyuContext != null;MetaData metaData = exchange.getAttribute(Constants.META_DATA);if (!checkMetaData(metaData)) {LOG.error(" path is : {}, meta data have error : {}", shenyuContext.getPath(), metaData);exchange.getResponse().setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.META_DATA_ERROR);return WebFluxResultUtils.result(exchange, error);}if (Objects.nonNull(metaData) && StringUtils.isNoneBlank(metaData.getParameterTypes()) && StringUtils.isBlank(param)) {exchange.getResponse().setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);Object error = ShenyuResultWrap.error(exchange, ShenyuResultEnum.DUBBO_HAVE_BODY_PARAM);return WebFluxResultUtils.result(exchange, error);}this.rpcContext(exchange);return this.doDubboInvoker(exchange, chain, selector, rule, metaData, param);}

ApacheDubboPlugin#doDubboInvoker，开始dubbo的泛化调用。

    @Overrideprotected Mono<Void> doDubboInvoker(final ServerWebExchange exchange,final ShenyuPluginChain chain,final SelectorData selector,final RuleData rule,final MetaData metaData,final String param) {RpcContext.getContext().setAttachment(Constants.DUBBO_SELECTOR_ID, selector.getId());RpcContext.getContext().setAttachment(Constants.DUBBO_RULE_ID, rule.getId());RpcContext.getContext().setAttachment(Constants.DUBBO_REMOTE_ADDRESS, Objects.requireNonNull(exchange.getRequest().getRemoteAddress()).getAddress().getHostAddress());final Mono<Object> result = dubboProxyService.genericInvoker(param, metaData, exchange);return result.then(chain.execute(exchange));}

ApacheDubboProxyService#genericInvoker

• 获取ReferenceConfig对象；
• 获取泛化服务GenericService对象；
• 构造请求参数pair对象；
• 发起异步的泛化调用。

    public Mono<Object> genericInvoker(final String body, final MetaData metaData, final ServerWebExchange exchange) throws ShenyuException {String referenceKey = metaData.getPath();String namespace = "";if (CollectionUtils.isNotEmpty(exchange.getRequest().getHeaders().get(Constants.NAMESPACE))) {namespace = exchange.getRequest().getHeaders().get(Constants.NAMESPACE).get(0);referenceKey = namespace + ":" + referenceKey;}ReferenceConfig<GenericService> reference = ApacheDubboConfigCache.getInstance().get(referenceKey);if (StringUtils.isEmpty(reference.getInterface())) {ApacheDubboConfigCache.getInstance().invalidate(referenceKey);reference = ApacheDubboConfigCache.getInstance().initRefN(metaData, namespace);}GenericService genericService = reference.get();Pair<String[], Object[]> pair;if (StringUtils.isBlank(metaData.getParameterTypes()) || ParamCheckUtils.bodyIsEmpty(body)) {pair = new ImmutablePair<>(new String[]{}, new Object[]{});} else {pair = dubboParamResolveService.buildParameter(body, metaData.getParameterTypes());}return Mono.fromFuture(invokeAsync(genericService, metaData.getMethodName(), pair.getLeft(), pair.getRight()).thenApply(ret -> {if (Objects.isNull(ret)) {ret = Constants.DUBBO_RPC_RESULT_EMPTY;}exchange.getAttributes().put(Constants.RPC_RESULT, ret);exchange.getAttributes().put(Constants.CLIENT_RESPONSE_RESULT_TYPE, ResultEnum.SUCCESS.getName());return ret;})).onErrorMap(exception -> exception instanceof GenericException ? new ShenyuException(((GenericException) exception).getExceptionMessage()) : new ShenyuException(exception));}@SuppressWarnings("unchecked")private CompletableFuture<Object> invokeAsync(final GenericService genericService, final String method, final String[] parameterTypes, final Object[] args) throws GenericException {//Compatible with asynchronous calls of lower Dubbo versionsgenericService.$invoke(method, parameterTypes, args);Object resultFromFuture = RpcContext.getContext().getFuture();return resultFromFuture instanceof CompletableFuture ? (CompletableFuture<Object>) resultFromFuture : CompletableFuture.completedFuture(resultFromFuture);}

ResponsePlugin#execute，处理响应结果

    @Overridepublic Mono<Void> execute(final ServerWebExchange exchange, final ShenyuPluginChain chain) {ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);assert shenyuContext != null;return writerMap.get(shenyuContext.getRpcType()).writeWith(exchange, chain);}

服务注册

启动shenyu-examples里面的shenyu-examples-apache-dubbo-service-annotation。

AbstractContextRefreshedEventListener

• 读取属性配置
• 开启线程池
• 启动注册中心，用于向shenyu-admin注册

    public AbstractContextRefreshedEventListener(final PropertiesConfig clientConfig,final ShenyuClientRegisterRepository shenyuClientRegisterRepository) {Properties props = clientConfig.getProps();this.appName = props.getProperty(ShenyuClientConstants.APP_NAME);this.contextPath = Optional.ofNullable(props.getProperty(ShenyuClientConstants.CONTEXT_PATH)).map(UriUtils::repairData).orElse("");if (StringUtils.isBlank(appName) && StringUtils.isBlank(contextPath)) {String errorMsg = "client register param must config the appName or contextPath";LOG.error(errorMsg);throw new ShenyuClientIllegalArgumentException(errorMsg);}this.ipAndPort = props.getProperty(ShenyuClientConstants.IP_PORT);this.host = props.getProperty(ShenyuClientConstants.HOST);this.port = props.getProperty(ShenyuClientConstants.PORT);publisher.start(shenyuClientRegisterRepository);}

AbstractContextRefreshedEventListener#onApplicationEvent，获取所有的ServiceBean的Bean，处理元数据对象和处理URI对象。

    @Overridepublic void onApplicationEvent(@NonNull final ContextRefreshedEvent event) {final ApplicationContext context = event.getApplicationContext();Map<String, T> beans = getBeans(context);if (MapUtils.isEmpty(beans)) {return;}if (!registered.compareAndSet(false, true)) {return;}publisher.publishEvent(buildURIRegisterDTO(context, beans));beans.forEach(this::handle);Map<String, Object> apiModules = context.getBeansWithAnnotation(ApiModule.class);apiModules.forEach((k, v) -> handleApiDoc(v, beans));}

ShenyuClientRegisterEventPublisher#publishEvent，使用disruptor来处理事件。

    public void publishEvent(final DataTypeParent data) {DisruptorProvider<DataTypeParent> provider = providerManage.getProvider();provider.onData(data);}

在RegisterCenterConfiguration注入ShenyuClientServerRegisterRepository

    @Bean(destroyMethod = "close")public ShenyuClientServerRegisterRepository shenyuClientServerRegisterRepository(final ShenyuRegisterCenterConfig shenyuRegisterCenterConfig,final List<ShenyuClientRegisterService> shenyuClientRegisterService) {String registerType = shenyuRegisterCenterConfig.getRegisterType();ShenyuClientServerRegisterRepository registerRepository = ExtensionLoader.getExtensionLoader(ShenyuClientServerRegisterRepository.class).getJoin(registerType);RegisterClientServerDisruptorPublisher publisher = RegisterClientServerDisruptorPublisher.getInstance();Map<String, ShenyuClientRegisterService> registerServiceMap = shenyuClientRegisterService.stream().collect(Collectors.toMap(ShenyuClientRegisterService::rpcType, Function.identity()));publisher.start(registerServiceMap);registerRepository.init(publisher, shenyuRegisterCenterConfig);return registerRepository;}

DisruptorProviderManage#startup(boolean)，启动DisruptorProviderManage会创建Disruptor

    public void startup(final boolean isOrderly) {OrderlyExecutor executor = new OrderlyExecutor(isOrderly, consumerSize, consumerSize, 0, TimeUnit.MILLISECONDS,new LinkedBlockingQueue<>(),DisruptorThreadFactory.create("shenyu_disruptor_consumer_", false), new ThreadPoolExecutor.AbortPolicy());int newConsumerSize = this.consumerSize;EventFactory<DataEvent<T>> eventFactory;if (isOrderly) {newConsumerSize = 1;eventFactory = new OrderlyDisruptorEventFactory<>();} else {eventFactory = new DisruptorEventFactory<>();}Disruptor<DataEvent<T>> disruptor = new Disruptor<>(eventFactory,size,DisruptorThreadFactory.create("shenyu_disruptor_provider_" + consumerFactory.fixName(), false),ProducerType.MULTI,new BlockingWaitStrategy());@SuppressWarnings("all")QueueConsumer<T>[] consumers = new QueueConsumer[newConsumerSize];for (int i = 0; i < newConsumerSize; i++) {consumers[i] = new QueueConsumer<>(executor, consumerFactory);}disruptor.handleEventsWithWorkerPool(consumers);disruptor.setDefaultExceptionHandler(new IgnoreExceptionHandler());disruptor.start();RingBuffer<DataEvent<T>> ringBuffer = disruptor.getRingBuffer();provider = new DisruptorProvider<>(ringBuffer, disruptor, isOrderly);}

RegisterServerConsumerExecutor用来处理Disruptor中的数据，选择执行器

    @Overridepublic void run() {Collection<DataTypeParent> results = getData().stream().filter(this::isValidData).collect(Collectors.toList());if (CollectionUtils.isEmpty(results)) {return;}selectExecutor(results).executor(results);}

MetadataExecutorSubscriber#executor，根据rpcType获取shenyuClientRegisterService。

    @Overridepublic void executor(final Collection<MetaDataRegisterDTO> metaDataRegisterDTOList) {metaDataRegisterDTOList.forEach(meta -> {Optional.ofNullable(this.shenyuClientRegisterService.get(meta.getRpcType())).ifPresent(shenyuClientRegisterService -> {synchronized (shenyuClientRegisterService) {shenyuClientRegisterService.register(meta);}});});}

AbstractShenyuClientRegisterServiceImpl#register，注册selector，ruleHandler，metadata和contextPath

    @Overridepublic String register(final MetaDataRegisterDTO dto) {//handler plugin selectorString selectorHandler = selectorHandler(dto);String selectorId = selectorService.registerDefault(dto, PluginNameAdapter.rpcTypeAdapter(rpcType()), selectorHandler);//handler selector ruleString ruleHandler = ruleHandler();RuleDTO ruleDTO = buildRpcDefaultRuleDTO(selectorId, dto, ruleHandler);ruleService.registerDefault(ruleDTO);//handler register metadataregisterMetadata(dto);//handler context pathString contextPath = dto.getContextPath();if (StringUtils.isNotEmpty(contextPath)) {registerContextPath(dto);}return ShenyuResultMessage.SUCCESS;}

RuleServiceImpl#registerDefault，判断数据库中是否存在

    @Overridepublic String registerDefault(final RuleDTO ruleDTO) {if (Objects.nonNull(ruleMapper.findBySelectorIdAndName(ruleDTO.getSelectorId(), ruleDTO.getName()))) {return "";}RuleDO ruleDO = RuleDO.buildRuleDO(ruleDTO);if (StringUtils.isEmpty(ruleDTO.getId())) {ruleMapper.insertSelective(ruleDO);addCondition(ruleDO, ruleDTO.getRuleConditions());}ruleEventPublisher.onRegister(ruleDO, ruleDTO.getRuleConditions());return ruleDO.getId();}

DataChangedEventDispatcher用于监听DataChangedEvent

    public void onApplicationEvent(final DataChangedEvent event) {for (DataChangedListener listener : listeners) {switch (event.getGroupKey()) {case APP_AUTH:listener.onAppAuthChanged((List<AppAuthData>) event.getSource(), event.getEventType());break;case PLUGIN:listener.onPluginChanged((List<PluginData>) event.getSource(), event.getEventType());break;case RULE:listener.onRuleChanged((List<RuleData>) event.getSource(), event.getEventType());break;case SELECTOR:listener.onSelectorChanged((List<SelectorData>) event.getSource(), event.getEventType());applicationContext.getBean(LoadServiceDocEntry.class).loadDocOnSelectorChanged((List<SelectorData>) event.getSource(), event.getEventType());break;case META_DATA:listener.onMetaDataChanged((List<MetaData>) event.getSource(), event.getEventType());break;default:throw new IllegalStateException("Unexpected value: " + event.getGroupKey());}}}

AbstractListDataChangedListener#onRuleChanged，规则改变执行该方法。

    @Overridepublic void onRuleChanged(final List<RuleData> changed, final DataEventTypeEnum eventType) {updateRuleMap(getConfig(changeData.getRuleDataId()));switch (eventType) {case DELETE:changed.forEach(rule -> {List<RuleData> ls = RULE_MAP.getOrDefault(rule.getSelectorId(), new ArrayList<>()).stream().filter(s -> !s.getId().equals(rule.getId())).sorted(RULE_DATA_COMPARATOR).collect(Collectors.toList());RULE_MAP.put(rule.getSelectorId(), ls);});break;case REFRESH:case MYSELF:Set<String> selectIdSet = changed.stream().map(RuleData::getSelectorId).collect(Collectors.toSet());RULE_MAP.keySet().removeAll(selectIdSet);changed.forEach(rule -> {List<RuleData> ls = new ArrayList<>(RULE_MAP.getOrDefault(rule.getSelectorId(),new ArrayList<>()));ls.add(rule);ls.sort(RULE_DATA_COMPARATOR);RULE_MAP.put(rule.getSelectorId(), ls);});break;default:changed.forEach(rule -> {List<RuleData> ls = RULE_MAP.getOrDefault(rule.getSelectorId(), new ArrayList<>()).stream().filter(s -> !s.getId().equals(rule.getId())).collect(Collectors.toList());ls.add(rule);ls.sort(RULE_DATA_COMPARATOR);RULE_MAP.put(rule.getSelectorId(), ls);});break;}publishConfig(changeData.getRuleDataId(), RULE_MAP);LOG.debug("[DataChangedListener] RuleChanged {}", changeData.getRuleDataId());}

NacosDataChangedListener#publishConfig，使用nacos发布配置。

    @Overridepublic void publishConfig(final String dataId, final Object data) {try {configService.publishConfig(dataId, NacosPathConstants.GROUP, GsonUtils.getInstance().toJson(data),ConfigType.JSON.getType());} catch (NacosException e) {LOG.error("Publish data to nacos error.", e);throw new ShenyuException(e.getMessage());}}

总结一下

1. 应用服务往注册中心发布信息，网关服务从注册中心上拉取信息。
2. 网关服务根据请求匹配选择器和规则，经过一系列的执行链，调用应用服务。相比于gateway，省去了配置服务的工作。