Soul 网关源码阅读（六）Sofa请求处理概览

简介

今天来探索一下Sofa请求处理流程，看看和前面的HTTP、Dubbo有什么异同

Sofa示例运行

PS：如果请求加上参数运行不成功，请更新最新版本，此问题在新版本中已经修复：https://blog.csdn.net/baidu_27627251/article/details/112726694
Add sofa param resolve service

首先运行下官方的Sofa示例，首先启动下mysql和zookeeper，这里使用docker启动：

docker run -dit --name zk -p 2181:2181 zookeepe
docker run --name mysql -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 -d mysql:latest

然后运行Soul-admin，Soul-Bootst，在管理图界面起用sofa插件

运行官方示例：soul-examples --> soul-examples-sofa

这里有个坑，需要注意，启动后，bootstrap打印日志中没有sofa插件，请求一直失败

o.d.s.w.configuration.SoulConfiguration  : load plugin:[global] [org.dromara.soul.plugin.global.GlobalPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[sign] [org.dromara.soul.plugin.sign.SignPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[waf] [org.dromara.soul.plugin.waf.WafPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[rate_limiter] [org.dromara.soul.plugin.ratelimiter.RateLimiterPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[hystrix] [org.dromara.soul.plugin.hystrix.HystrixPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[resilience4j] [org.dromara.soul.plugin.resilience4j.Resilience4JPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[divide] [org.dromara.soul.plugin.divide.DividePlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[webClient] [org.dromara.soul.plugin.httpclient.WebClientPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[divide] [org.dromara.soul.plugin.divide.websocket.WebSocketPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[alibaba-dubbo-body-param] [org.dromara.soul.plugin.alibaba.dubbo.param.BodyParamPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[dubbo] [org.dromara.soul.plugin.alibaba.dubbo.AlibabaDubboPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[monitor] [org.dromara.soul.plugin.monitor.MonitorPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[response] [org.dromara.soul.plugin.httpclient.response.WebClientResponsePlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[response] [org.dromara.soul.plugin.alibaba.dubbo.response.DubboResponsePlugin]
```xml&ensp;&ensp;&ensp;&ensp;查看初始的plugins也是没有sofa```javapublic SoulWebHandler soulWebHandler(final ObjectProvider<List<SoulPlugin>> plugins) {List<SoulPlugin> pluginList = plugins.getIfAvailable(Collections::emptyList);final List<SoulPlugin> soulPlugins = pluginList.stream().sorted(Comparator.comparingInt(SoulPlugin::getOrder)).collect(Collectors.toList());soulPlugins.forEach(soulPlugin -> log.info("load plugin:[{}] [{}]", soulPlugin.named(), soulPlugin.getClass().getName()));return new SoulWebHandler(soulPlugins);}

经过探索和老哥的讨论，发现是每天起用sofa的相关依赖

我们在Bootstrap的pom.xml文件中添加下面的依赖，然后重启

        <!--        sofa plugin start--><dependency><groupId>com.alipay.sofa</groupId><artifactId>sofa-rpc-all</artifactId><version>5.7.6</version></dependency><dependency><groupId>org.apache.curator</groupId><artifactId>curator-client</artifactId><version>4.0.1</version></dependency><dependency><groupId>org.apache.curator</groupId><artifactId>curator-framework</artifactId><version>4.0.1</version></dependency><dependency><groupId>org.apache.curator</groupId><artifactId>curator-recipes</artifactId><version>4.0.1</version></dependency><dependency><groupId>org.dromara</groupId><artifactId>soul-spring-boot-starter-plugin-sofa</artifactId><version>${project.version}</version></dependency><!--        sofa plugin end-->

然后查看日志打印，出现了sofa相关的插件

o.d.s.w.configuration.SoulConfiguration  : load plugin:[global] [org.dromara.soul.plugin.global.GlobalPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[sign] [org.dromara.soul.plugin.sign.SignPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[waf] [org.dromara.soul.plugin.waf.WafPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[rate_limiter] [org.dromara.soul.plugin.ratelimiter.RateLimiterPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[hystrix] [org.dromara.soul.plugin.hystrix.HystrixPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[resilience4j] [org.dromara.soul.plugin.resilience4j.Resilience4JPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[divide] [org.dromara.soul.plugin.divide.DividePlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[webClient] [org.dromara.soul.plugin.httpclient.WebClientPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[divide] [org.dromara.soul.plugin.divide.websocket.WebSocketPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[sofa-body-param] [org.dromara.soul.plugin.sofa.param.BodyParamPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[dubbo] [org.dromara.soul.plugin.alibaba.dubbo.AlibabaDubboPlugin]
// 新出现的sofa相关的
o.d.s.w.configuration.SoulConfiguration  : load plugin:[sofa] [org.dromara.soul.plugin.sofa.SofaPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[monitor] [org.dromara.soul.plugin.monitor.MonitorPlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[response] [org.dromara.soul.plugin.alibaba.dubbo.response.DubboResponsePlugin]
o.d.s.w.configuration.SoulConfiguration  : load plugin:[response] [org.dromara.soul.plugin.httpclient.response.WebClientResponsePlugin]
// 新出现的sofa相关的
o.d.s.w.configuration.SoulConfiguration  : load plugin:[response] [org.dromara.soul.plugin.sofa.response.SofaResponsePlugin]

日志中还打印了成功加载sofa相关的metadata

o.d.s.p.s.cache.ApplicationConfigCache   : init sofa reference success there meteData is :MetaData
o.d.s.p.s.cache.ApplicationConfigCache   : init sofa reference success there meteData is :MetaData
o.d.s.p.s.cache.ApplicationConfigCache   : init sofa reference success there meteData is :MetaData

访问链接： http://localhost:9195/sofa/findAll ，成功返回如下请求

{"code": 200,"message": "Access to success!","data": {"name": "hello world Soul Sofa , findAll","id": "998932133"}
}

源码解析

PS:Debug时间过程，会导致超时，这是正常的

首先找到我们非常熟悉的切入点函数： SoulWebHandler ，在下面的方法中打上断点，然后逐步进入每个plugin观察其行为

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

GlobalPlugin

进入其中，执行处理逻辑，通过上篇的分析，我们知道大致作用是将请求类型放入exchange中

SignPlugin/WafPlugin/RateLimiterPlugin/HystrixPlugin/Resilience4JPlugin

进入其中，但plugin没有起用，不执行逻辑

DividePlugin/WebClientPlugin/WebSocketPlugin

通过类型判断，跳过，不执行

BodyParamPlugin

这个plugin在dubbo的时候也是要执行，我们来看看它干了写啥事。从下面逻辑中大概能看出先判断是否符合执行条件，然后将请求地址替换成真实的后端地址

    public Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {final ServerHttpRequest request = exchange.getRequest();final SoulContext soulContext = exchange.getAttribute(Constants.CONTEXT);// 判断类型是不是sofaif (Objects.nonNull(soulContext) && RpcTypeEnum.SOFA.getName().equals(soulContext.getRpcType())) {MediaType mediaType = request.getHeaders().getContentType();ServerRequest serverRequest = ServerRequest.create(exchange, messageReaders);if (MediaType.APPLICATION_JSON.isCompatibleWith(mediaType)) {return body(exchange, serverRequest, chain);}if (MediaType.APPLICATION_FORM_URLENCODED.isCompatibleWith(mediaType)) {return formData(exchange, serverRequest, chain);}// 进行路径替换，换成后端服务器的return query(exchange, serverRequest, chain);}return chain.execute(exchange);}private Mono<Void> query(final ServerWebExchange exchange, final ServerRequest serverRequest, final SoulPluginChain chain) {exchange.getAttributes().put(Constants.SOFA_PARAMS,HttpParamConverter.ofString(() -> serverRequest.uri().getQuery()));return chain.execute(exchange);}

这里有个非常有趣的现象，我们第四篇分析中，dubbo也走了一模一样的类，在上面函数逻辑中，我们看出它并不能兼容dubbo，那dubbo是如何走这个类的呢？

通过调试我们发现，当同时启动dubbo和sofa的时候，会生成两个BodyParamPlugin,名称是一模一样的，但里面的判断类型换了，很神奇，猜测这个类是动态生成之类的手段，这里先不探索了，可以后面研究研究

AlibabaDubboPlugin

通过类型判断，跳过

SofaPlugin

这个从名字就看出来是核心类，我们看看它具体干了啥。通过下面注释的地方，可以看出和dubbo请求的非常的相像。进行路由匹配，成功后rpc调用，获得结果后放入exchange中

    # AbstractSoulPluginpublic Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {String pluginName = named();final PluginData pluginData = BaseDataCache.getInstance().obtainPluginData(pluginName);if (pluginData != null && pluginData.getEnabled()) {final Collection<SelectorData> selectors = BaseDataCache.getInstance().obtainSelectorData(pluginName);if (CollectionUtils.isEmpty(selectors)) {return handleSelectorIsNull(pluginName, exchange, chain);}final SelectorData selectorData = matchSelector(exchange, selectors);if (Objects.isNull(selectorData)) {return handleSelectorIsNull(pluginName, exchange, chain);}selectorLog(selectorData, pluginName);final List<RuleData> rules = BaseDataCache.getInstance().obtainRuleData(selectorData.getId());if (CollectionUtils.isEmpty(rules)) {return handleRuleIsNull(pluginName, exchange, chain);}// 判断是否有路由规则能匹配上RuleData rule;if (selectorData.getType() == SelectorTypeEnum.FULL_FLOW.getCode()) {//get lastrule = rules.get(rules.size() - 1);} else {rule = matchRule(exchange, rules);}if (Objects.isNull(rule)) {return handleRuleIsNull(pluginName, exchange, chain);}ruleLog(rule, pluginName);// 匹配上后执行处理逻辑return doExecute(exchange, chain, selectorData, rule);}return chain.execute(exchange);}# SofaPluginprotected Mono<Void> doExecute(final ServerWebExchange exchange, final SoulPluginChain chain, final SelectorData selector, final RuleData rule) {String body = exchange.getAttribute(Constants.SOFA_PARAMS);SoulContext soulContext = exchange.getAttribute(Constants.CONTEXT);assert soulContext != null;MetaData metaData = exchange.getAttribute(Constants.META_DATA);if (!checkMetaData(metaData)) {assert metaData != null;log.error(" path is :{}, meta data have error.... {}", soulContext.getPath(), metaData.toString());exchange.getResponse().setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);Object error = SoulResultWrap.error(SoulResultEnum.META_DATA_ERROR.getCode(), SoulResultEnum.META_DATA_ERROR.getMsg(), null);return WebFluxResultUtils.result(exchange, error);}if (StringUtils.isNoneBlank(metaData.getParameterTypes()) && StringUtils.isBlank(body)) {exchange.getResponse().setStatusCode(HttpStatus.INTERNAL_SERVER_ERROR);Object error = SoulResultWrap.error(SoulResultEnum.SOFA_HAVE_BODY_PARAM.getCode(), SoulResultEnum.SOFA_HAVE_BODY_PARAM.getMsg(), null);return WebFluxResultUtils.result(exchange, error);}// 这里得到结果，跟下去final Mono<Object> result = sofaProxyService.genericInvoker(body, metaData, exchange);return result.then(chain.execute(exchange));}# SofaProxyServicepublic Mono<Object> genericInvoker(final String body, final MetaData metaData, final ServerWebExchange exchange) throws SoulException {// 根据请求路径，获得rpc中的consumer ConsumerConfig<GenericService> reference = ApplicationConfigCache.getInstance().get(metaData.getPath());if (Objects.isNull(reference) || StringUtils.isEmpty(reference.getInterfaceId())) {ApplicationConfigCache.getInstance().invalidate(metaData.getServiceName());reference = ApplicationConfigCache.getInstance().initRef(metaData);}GenericService genericService = reference.refer();Pair<String[], Object[]> pair;if (null == body || "".equals(body) || "{}".equals(body) || "null".equals(body)) {pair = new ImmutablePair<>(new String[]{}, new Object[]{});} else {pair = sofaParamResolveService.buildParameter(body, metaData.getParameterTypes());}CompletableFuture<Object> future = new CompletableFuture<>();RpcInvokeContext.getContext().setResponseCallback(new SofaResponseCallback<Object>() {@Overridepublic void onAppResponse(final Object o, final String s, final RequestBase requestBase) {future.complete(o);}@Overridepublic void onAppException(final Throwable throwable, final String s, final RequestBase requestBase) {future.completeExceptionally(throwable);}@Overridepublic void onSofaException(final SofaRpcException e, final String s, final RequestBase requestBase) {future.completeExceptionally(e);}});// 通过函数名，能猜到是rpc调用，然后得到结果，并将结果放入exchange中genericService.$invoke(metaData.getMethodName(), pair.getLeft(), pair.getRight());return Mono.fromFuture(future.thenApply(ret -> {if (Objects.isNull(ret)) {ret = Constants.SOFA_RPC_RESULT_EMPTY;}exchange.getAttributes().put(Constants.SOFA_RPC_RESULT, ret);exchange.getAttributes().put(Constants.CLIENT_RESPONSE_RESULT_TYPE, ResultEnum.SUCCESS.getName());return ret;})).onErrorMap(SoulException::new);}

MonitorPlugin

不跳过，但插件没有开启

DubboResponsePlugin/WebClientResponsePlugin

通过类型判断，跳过执行

SofaResponsePlugin

通过上几篇分析和名字能猜出来是将响应返回给客户端的，通过下面代码的逻辑也可以看出

    public Mono<Void> execute(final ServerWebExchange exchange, final SoulPluginChain chain) {return chain.execute(exchange).then(Mono.defer(() -> {// 从exchange中获取结果final Object result = exchange.getAttribute(Constants.SOFA_RPC_RESULT);if (Objects.isNull(result)) {Object error = SoulResultWrap.error(SoulResultEnum.SERVICE_RESULT_ERROR.getCode(), SoulResultEnum.SERVICE_RESULT_ERROR.getMsg(), null);return WebFluxResultUtils.result(exchange, error);}Object success = SoulResultWrap.success(SoulResultEnum.SUCCESS.getCode(), SoulResultEnum.SUCCESS.getMsg(), JsonUtils.removeClass(result));// 熟悉的返回响应的函数return WebFluxResultUtils.result(exchange, success);}));}

总结

上面的plugin流程大致如下：

GlobalPlugin : 将请求类型置入
SignPlugin : 跳过不执行逻辑
WafPlugin : 跳过不执行逻辑
RateLimiterPlugin : 跳过不执行逻辑
HystrixPlugin : 跳过不执行逻辑
Resilience4JPlugin : 跳过不执行逻辑
DividePlugin : 跳过不执行逻辑
WebClientPlugin : 跳过不执行逻辑
WebSocketPlugin : 跳过不执行逻辑
BodyParamPlugin : 执行RPC的请求路径替换，替换成真实的服务器后端路径，作用类似于dividePlugin；不同rpc有相关的这个插件名，也就是会有多个BodyParamPlugin
AlibabaDubboPlugin : 跳过不执行逻辑
SofaPlugin : 发送请求到后台服务器，拿到结果，写入exchange
MonitorPlugin : 跳过不执行逻辑
DubboResponsePlugin : 跳过不执行逻辑
WebClientResponsePlugin : 跳过不执行逻辑
SofaResponsePlugin : 从exchange中拿到响应，发送给客户端

经过这几篇的分析，我们进一步优化我们对Soul网关的请求流程，大致如下：

更新了我们对处理流程中一些类的认知：

通过上篇分析，得到GlobalPlugin的具体作用，是置入请求类型
BodyParamPlugin 作用类似于 dividePlugin，能进行路由匹配，匹配后将路径修改真实的后端服务器路径；并且能动态的生成同名的但针对不同rpc实现的plugin

Soul网关源码分析文章列表

Github

Soul 源码阅读（一）概览
Soul 源码阅读（二）代码初步运行
Soul 源码阅读（三）HTTP请求处理概览
Soul 网关源码阅读（四）Dubbo请求概览
Soul网关源码阅读（五）请求类型探索
Soul 网关源码阅读（六）Sofa请求处理概览

掘金

Soul 网关源码阅读（一）概览 #掘金文章# https://juejin.cn/post/6917864624423436296
Soul 网关源码阅读（二）代码初步运行 #掘金文章# https://juejin.cn/post/6917865804121767944
Soul 网关源码阅读（三）请求处理概览 #掘金文章# https://juejin.cn/post/6917866538712334343
Soul 网关源码阅读（四）Dubbo请求概览 #掘金文章# https://juejin.cn/post/6917867369909977102
Soul网关源码阅读（五）请求类型探索 #掘金文章# https://juejin.cn/post/6918575905962983438