Soul 网关源码阅读（六）Sofa 请求处理概览

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

    查看初始的plugins也是没有sofa

```java
public 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sofa
if (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

# AbstractSoulPlugin
public 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 last
rule = 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);
}

# SofaPlugin
protected 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));
}

# SofaProxyService
public 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>() {
@Override
public void onAppResponse(final Object o, final String s, final RequestBase requestBase) {
future.complete(o);
}

@Override
public void onAppException(final Throwable throwable, final String s, final RequestBase requestBase) {
future.completeExceptionally(throwable);
}

@Override
public 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