Dubbo-go Server端开启服务过程

{"type":"doc","content":[{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"导读"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"导读：随着微服务架构的流行，许多高性能 rpc 框架应运而生，由阿里开源的 dubbo 框架 go 语言版本的 dubbo-go 也成为了众多开发者不错的选择。本文将介绍 dubbo-go 框架的基本使用方法，以及从 export 调用链的角度进行 server 端源码导读，希望能引导读者进一步认识这款框架。下周将发表本文的姊妹篇：《从 client 端源码导读 dubbo-go 框架》。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"序言"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"近日阅读了部分dubbo-go源码"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"link","attrs":{"href":"https://github.com/dubbogo/dubbo-go","title":""},"content":[{"type":"text","text":"https://github.com/dubbogo/dubbo-go"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"当拿到一款框架之后，一种不错的源码阅读方式大致如下：从运行最基础的helloworld demo 源码开始，再查看配置文件，开启各种依赖服务（比如zk、consul），开启服务端，再到通过client调用服务端，打印完整请求日志和回包。调用成功之后，再根据框架的设计模型，从配置文件解析开始，自顶向下递阅读整个框架的调用栈。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"对于C/S模式的rpc请求来说，整个调用栈被拆成了client和server两部分，所以可以分别从server端的配置文件解析阅读到server端的监听启动，从client端的配置文件解析阅读到一次invoker Call 调用。这样一次完整请求就明晰了起来。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"1. 运行官网提供的helloworld-demo"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"link","attrs":{"href":"https://github.com/dubbogo/dubbo-samples/tree/master/golang/helloworld/dubbo","title":""},"content":[{"type":"text","text":"官方demo"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1.1 dubbo-go 2.7版本 QuickStart"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"1. 开启一个go-server服务"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"将仓库clone 到本地"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ git clone "},{"type":"link","attrs":{"href":"https://github.com/dubbogo/dubbo-samples.git","title":""},"content":[{"type":"text","text":"https://github.com/dubbogo/dubbo-samples.git"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"进入dubbo目录"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ cd dubbo-samples/golang/helloworld/dubbo"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"进入目录后可看到四个文件夹，分别支持go和java的client以及server，我们尝试运行一个go的server"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"进入app子文件夹内，可以看到里面保存了go文件。"}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ cd go-server/app"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"sample文件结构："}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"可在go-server里面看到三个文件夹：app、assembly、profiles"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其中app文件夹下保存go源码，assembly文件夹下保存可选的针对特定环境的build脚本，profiles下保存配置文件。对于dubbo-go框架，配置文件非常重要，没有文件将导致服务无法启动。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"设置指向配置文件的环境变量"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"由于dubbo-go框架依赖配置文件启动，让框架定位到配置文件的方式就是通过环境变量来找。对于server端需要两个必须配置的环境变量：CONF"},{"type":"text","marks":[{"type":"italic"}],"text":"PROVIDER"},{"type":"text","text":"FILE_PATH、APP_LOG"},{"type":"text","marks":[{"type":"italic"}],"text":"CONF"},{"type":"text","text":"FILE，分别应该指向服务端配置文件、日志配置文件。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在sample里面，我们可以使用dev环境，即profiles/dev/log.yml profiles/dev/server.yml 两个文件。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在app/下，通过命令行中指定好这两个文件："}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ export CONF"},{"type":"text","marks":[{"type":"italic"}],"text":"PROVIDER"},{"type":"text","text":"FILE_PATH=\"../profiles/dev/server.yml\""}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ export APP"},{"type":"text","marks":[{"type":"italic"}],"text":"LOG"},{"type":"text","text":"CONF_FILE=\"../profiles/dev/log.yml\""}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"设置go代理并运行服务"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ go run ."}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"如果提示timeout，则需要设置goproxy代理"}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ export GOPROXY=\"http://goproxy.io\""}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"再运行go run 即可开启服务"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2. 运行zookeeper"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"安装zookeeper，并运行zkServer, 默认为2181端口"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"3. 运行go-client调用server服务"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"进入go-client的源码目录"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ cd 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APP"},{"type":"text","marks":[{"type":"italic"}],"text":"LOG"},{"type":"text","text":"CONF_FILE=\"../profiles/dev/log.yml\""}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"配置go代理"}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ export GOPROXY=\"http://goproxy.io\""}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"运行程序"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"$ go run ."}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"即可在日志中找到打印出的请求结果"}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"response result: &{A001 Alex Stocks 18 2020-10-28 14:52:49.131 +0800 CST}"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"同样，在运行的server中，也可以在日志中找到打印出的请求："}]},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"req:[]interface {}{\"A001\"}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"rsp:main.User{Id:\"A001\", Name:\"Alex Stocks\", Age:18, Time:time.Time{...}"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"恭喜！一次基于dubbo-go的rpc调用成功。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"4. 常见问题"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"1. 当日志开始部分出现profiderInit和ConsumerInit均失败的日志。检查环境变量中配置路径是否正确，配置文件是否正确。"}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"2. 当日志中出现register失败的情况，一般为向注册中心注册失败，检查注册中心是否开启，检查配置文件中关于register的端口是否正确。"}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"3. sample的默认开启端口为20000，确保启动前无占用"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1.2 配置环境变量"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"bash"},"content":[{"type":"text","text":"export APP_LOG_CONF_FILE=\"../profiles/dev/log.yml\"\nexport CONF_CONSUMER_FILE_PATH=\"../profiles/dev/client.yml\""}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1.3 服务端源码"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"1. 目录结构"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"dubbo-go框架的example提供的目录如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/78/7823224a8a2d5277c3dca579c6ab5bc8.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"bulletedlist","content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"app/ 文件夹下存放源码，可以自己编写环境变量配置脚本buliddev.sh"}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"assembly/ 文件夹下存放不同平台的构建脚本"}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"profiles/ 文件夹下存放不同环境的配置文件"}]}]},{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"target/ 文件夹下存放可执行文件"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2. 关键源码"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"源码放置在app/文件夹下，主要包含server.go 和user.go 两个文件，顾名思义，server.go用于使用框架开启服务以及注册传输协议，user.go则定义了rpc-service结构体，以及传输协议的结构。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"user.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\tconfig.SetProviderService(new(UserProvider))\n\t// ------for hessian2------\n\thessian.RegisterPOJO(&User{})\n}\ntype User struct {\n\tId string\n\tName string\n\tAge int32\n\tTime time.Time\n}\ntype UserProvider struct {\n}\nfunc (u *UserProvider) GetUser(ctx context.Context, req []interface{}) (*User, error) {"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"可以看到，user.go中存在init函数，是服务端代码中最先被执行的部分。User为用户自定义的传输结构体，UserProvider为用户自定义的rpc_service。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"包含一个rpc函数，GetUser。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"当然，用户可以自定义其他的rpc功能函数。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在init函数中，调用config的SetProviderService函数，将当前rpc_service注册在框架config上。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"**可以查看dubbo官方文档提供的"},{"type":"link","attrs":{"href":"http://dubbo.apache.org/zh-cn/docs/dev/design.html","title":""},"content":[{"type":"text","text":"设计图"}]},{"type":"text","text":"**"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/5f/5f5bd4d9e989d2ce49854a7e7a7a66a1.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"service层下面就是config层，用户服务会逐层向下注册，最终实现服务端的暴露。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"rpc-service注册完毕之后，调用hessian接口注册传输结构体User。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此init函数执行完毕"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"server.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// they are necessary:\n// \texport CONF_PROVIDER_FILE_PATH=\"xxx\"\n// \texport APP_LOG_CONF_FILE=\"xxx\"\nfunc main() {\n\thessian.RegisterPOJO(&User{})\n\tconfig.Load()\n\tinitSignal()\n}\nfunc initSignal() {\n\tsignals := make(chan os.Signal, 1)\n\t..."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"之后执行main函数"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"main函数中只进行了两个操作，首先使用hessian注册组件将User结构体注册（与之前略有重复），从而可以在接下来使用getty打解包。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"之后调用config.Load函数，该函数位于框架config/config_loader.go内，这个函数是整个框架服务的启动点，"},{"type":"text","marks":[{"type":"strong"}],"text":"下面会详细讲这个函数内重要的配置处理过程"},{"type":"text","text":"。执行完Load()函数之后，配置文件会读入框架，之后根据配置文件的内容，将注册的service实现到配置结构里，再调用Export暴露给特定的registry，进而开启特定的service进行对应端口的tcp监听，成功启动并且暴露服务。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"最终开启信号监听initSignal()优雅地结束一个服务的启动过程。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1.4 客户端源码"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"客户端包含client.go和user.go两个文件，其中user.go与服务端完全一致，不再赘述。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","marks":[{"type":"strong"}],"text":"client.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// they are necessary:\n// \texport CONF_CONSUMER_FILE_PATH=\"xxx\"\n// \texport APP_LOG_CONF_FILE=\"xxx\"\nfunc main() {\n\thessian.RegisterPOJO(&User{})\n\tconfig.Load()\n\ttime.Sleep(3e9)\n\tprintln(\"\\n\\n\\nstart to test dubbo\")\n\tuser := &User{}\n\terr := userProvider.GetUser(context.TODO(), []interface{}{\"A001\"}, user)\n\tif err != nil {\n panic(err)\n\t}\n\tprintln(\"response result: %v\\n\", user)\n\tinitSignal()\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"main函数和服务端也类似，首先将传输结构注册到hessian上，再调用config.Load()函数。在下文会介绍，客户端和服务端会根据配置类型执行config.Load()中特定的函数loadConsumerConfig()和loadProviderConfig()，从而达到“开启服务”、“调用服务”的目的。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"加载完配置之后，还是通过实现服务，增加函数proxy，申请registry，reloadInvoker指向服务端ip等操作，重写了客户端实例userProvider的对应函数，这时再通过调用GetUser函数，可以直接通过invoker，调用到已经开启的服务端，实现rpc过程。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"下面会从server端和client端两个角度，详细讲解服务启动、registry注册、调用过程："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"1.5 自定义配置文件（非环境变量）方法"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"1.5.1 服务端自定义配置文件"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"1","normalizeStart":1},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":1,"align":null,"origin":null},"content":[{"type":"text","text":"var providerConfigStr = "},{"type":"codeinline","content":[{"type":"text","text":"xxxxx"}]},{"type":"text","text":"// 配置文件内容，可以参考"},{"type":"link","attrs":{"href":"https://github.com/dubbogo/dubbo-samples/blob/master/golang/helloworld/dubbo/go-client/profiles/release/log.yml","title":""},"content":[{"type":"text","text":"log"}]},{"type":"text","text":" 和 [client](https://github.com/dubbogo/dubbo-samples/blob/master/golang/helloworld/dubbo/go-client/profiles/release/client.yml)"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" - 在这里你可以定义配置文件的获取方式，比如配置中心，本地文件读取"}]},{"type":"numberedlist","attrs":{"start":"2","normalizeStart":"2"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":2,"align":null,"origin":null},"content":[{"type":"text","text":"在"},{"type":"codeinline","content":[{"type":"text","text":"config.Load()"}]},{"type":"text","text":"之前设置配置，例如："}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func main() {\n\thessian.RegisterPOJO(&User{})\n\tproviderConfig := config.ProviderConfig{}\n\tyaml.Unmarshal([]byte(providerConfigStr), &providerConfig)\n\tconfig.SetProviderConfig(providerConfig)\n\tdefaultServerConfig := dubbo.GetDefaultServerConfig()\n\tdubbo.SetServerConfig(defaultServerConfig)\n\tlogger.SetLoggerLevel(\"warn\") // info,warn\n\tconfig.Load()\n\tselect {\n\t}\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"1.5.2 客户端自定义配置文件"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"1","normalizeStart":1},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":1,"align":null,"origin":null},"content":[{"type":"text","text":"var consumerConfigStr = "},{"type":"codeinline","content":[{"type":"text","text":"xxxxx"}]},{"type":"text","text":"// 配置文件内容，可以参考"},{"type":"link","attrs":{"href":"https://github.com/dubbogo/dubbo-samples/blob/master/golang/helloworld/dubbo/go-client/profiles/release/log.yml","title":""},"content":[{"type":"text","text":"log"}]},{"type":"text","text":" 和 [client](https://github.com/dubbogo/dubbo-samples/blob/master/golang/helloworld/dubbo/go-client/profiles/release/client.yml)"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" - 在这里你可以定义配置文件的获取方式，比如配置中心，本地文件读取"}]},{"type":"numberedlist","attrs":{"start":"2","normalizeStart":"2"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":2,"align":null,"origin":null},"content":[{"type":"text","text":"在"},{"type":"codeinline","content":[{"type":"text","text":"config.Load()"}]},{"type":"text","text":"之前设置配置，例如："}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func main() {\n p := config.ConsumerConfig{}\n yaml.Unmarshal([]byte(consumerConfigStr), &p)\n config.SetConsumerConfig(p)\n defaultClientConfig := dubbo.GetDefaultClientConfig()\n dubbo.SetClientConf(defaultClientConfig)\n logger.SetLoggerLevel(\"warn\") // info,warn\n config.Load()\n\n user := &User{}\n err := userProvider.GetUser(context.TODO(), []interface{}{\"A001\"}, user)\n if err != nil {\n log.Print(err)\n return\n }\n log.Print(user)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":1},"content":[{"type":"text","text":"2. server端："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"服务暴露过程涉及到多次原始rpcService的封装、暴露，网上其他文章的图感觉太过笼统，我简要的绘制了一个用户定义服务的数据流图"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/a8/a80738bfc1ea9a6e55292f823b03bb32.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.1 加载配置"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.1.1 框架初始化"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在加载配置之前，框架提供了很多已定义好的协议、工厂等组件，都会在对应模块init函数内注册到extension模块上，以供接下来配置文件中进行选用。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其中重要的有："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"1","normalizeStart":1},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":1,"align":null,"origin":null},"content":[{"type":"text","text":"默认函数代理工厂"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" common/proxy/proxy_factory/default.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\textension.SetProxyFactory(\"default\", NewDefaultProxyFactory)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"他的作用是将原始rpc-service进行封装，形成proxy_invoker，更易于实现远程call调用，详情可见其invoke函数。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"2","normalizeStart":"2"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":2,"align":null,"origin":null},"content":[{"type":"text","text":"注册中心注册协议"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" registry/protocol/protocol.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\textension.SetProtocol(\"registry\", GetProtocol)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"他负责在将invoker暴露给对应注册中心，比如zk注册中心。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"3","normalizeStart":"3"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":3,"align":null,"origin":null},"content":[{"type":"text","text":"zookeeper注册协议"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" registry/zookeeper/zookeeper.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\textension.SetRegistry(\"zookeeper\", newZkRegistry)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"他合并了base_resiger，负责在服务暴露过程中，将服务注册在zookeeper注册器上，从而为调用者提供调用方法。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"4","normalizeStart":"4"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":4,"align":null,"origin":null},"content":[{"type":"text","text":"dubbo传输协议"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" protocol/dubbo/dubbo.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\textension.SetProtocol(DUBBO, GetProtocol)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"他负责监听对应端口，将具体的服务暴露，并启动对应的事件handler，将远程调用的event事件传递到invoker内部，调用本地invoker并获得执行结果返回。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"numberedlist","attrs":{"start":"5","normalizeStart":"5"},"content":[{"type":"listitem","content":[{"type":"paragraph","attrs":{"indent":0,"number":5,"align":null,"origin":null},"content":[{"type":"text","text":"filter包装调用链协议"}]}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":" protocol/protocolwrapper/protocol"},{"type":"text","marks":[{"type":"italic"}],"text":"filter"},{"type":"text","text":"wrapper.go"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"func init() {\n\textension.SetProtocol(FILTER, GetProtocol)\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"他负责在服务暴露过程中，将代理invoker打包，通过配置好的filter形成调用链，并交付给dubbo协议进行暴露。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"上述提前注册好的框架已实现的组件，在整个服务暴露调用链中都会用到，会根据配置取其所需。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.1.2 配置文件"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"服务端需要的重要配置有三个字段：services、protocols、registries"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"profiles/dev/server.yaml:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"yaml"},"content":[{"type":"text","text":"registries :\n \"demoZk\":\n protocol: \"zookeeper\"\n timeout\t: \"3s\"\n address: \"127.0.0.1:2181\"\nservices:\n \"UserProvider\":\n # 可以指定多个registry，使用逗号隔开;不指定默认向所有注册中心注册\n registry: \"demoZk\"\n protocol : \"dubbo\"\n # 相当于dubbo.xml中的interface\n interface : \"com.ikurento.user.UserProvider\"\n loadbalance: \"random\"\n warmup: \"100\"\n cluster: \"failover\"\n methods:\n - name: \"GetUser\"\n retries: 1\n loadbalance: \"random\"\nprotocols:\n \"dubbo\":\n name: \"dubbo\"\n port: 20000"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其中service指定了要暴露的rpc-service名（\"UserProvider），暴露的协议名（\"dubbo\"），注册的协议名(\"demoZk\")，暴露的服务所处的interface，负载均衡策略，集群失败策略，调用的方法等等。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"其中中间服务的协议名需要和registries下的mapkey对应，暴露的协议名需要和protocols下的mapkey对应"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"可以看到上述例子中，使用了dubbo作为暴露协议，使用了zookeeper作为中间注册协议，并且给定了端口。如果zk需要设置用户名和密码，也可以在配置中写好。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.1.3 配置文件的读入和检查"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"config/config_loader.go:: Load()"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在上述example的main函数中，有config.Load()函数的直接调用，该函数执行细节如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// Load Dubbo Init\nfunc Load() {\n\t// init router\n\tinitRouter()\n\t// init the global event dispatcher\n\textension.SetAndInitGlobalDispatcher(GetBaseConfig().EventDispatcherType)\n\t// start the metadata report if config set\n\tif err := startMetadataReport(GetApplicationConfig().MetadataType, GetBaseConfig().MetadataReportConfig); err != nil {\n logger.Errorf(\"Provider starts metadata report error, and the error is {%#v}\", err)\n return\n\t}\n\t// reference config\n\tloadConsumerConfig()\n\t// service config\n\tloadProviderConfig()\n\t// init the shutdown callback\n\tGracefulShutdownInit()\n}"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在本文中，我们重点关心loadConsumerConfig()和loadProviderConfig()两个函数"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"对于provider端，可以看到loadProviderConfig()函数代码如下："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/a8/a8a9d5ab5174783ef11cc2baa49c560b.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"前半部分是配置的读入和检查，进入for循环后，是单个service的暴露起始点。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"前面提到，在配置文件中已经写好了要暴露的service的种种信息，比如服务名、interface名、method名等等。在图中for循环内，会将所有service的服务依次实现。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"for循环的第一行，根据key调用GetProviderService函数，拿到注册的rpcService实例，这里对应上述提到的init函数中用户手动注册的自己实现的rpc-service实例："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/8b/8bb9a2e1836795b7146d5c0acc88c7a9.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这个对象也就成为了for循环中的rpcService变量，将这个对象注册通过Implement函数写到sys（ServiceConfig类型）上，设置好sys的key和协议组，最终调用了sys的Export方法。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"此处对应流程图的部分："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/6d/6d4f49ed967e0df0e0a2d1eaf1db128b.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此，框架配置结构体已经拿到了所有service有关的配置，以及用户定义好的rpc-service实例，他触发了Export方法，旨在将自己的实例暴露出去。这是Export调用链的起始点。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.2 原始service封装入proxy_invoker"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"config/service_config.go :: Export()"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"接下来进入ServiceConfig.Export()函数："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这个函数进行了一些细碎的操作，比如为不同的协议分配随机端口，如果指定了多个中心注册协议，则会将服务通过多个中心注册协议的registryProtocol暴露出去，我们只关心对于一个注册协议是如何操作的。还有一些操作比如生成调用url和注册url，用于为暴露做准备。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.2.1 首先通过配置生成对应registryUrl和serviceUrl"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/d2/d27db4b336ea63941233caed29fd8601.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"registryUrl是用来向中心注册组件发起注册请求的，对于zookeeper的话，会传入其ip和端口号，以及附加的用户名密码等信息"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这个regUrl目前只存有注册（zk）相关信息，后续会补写入ServiceIvk，即服务调用相关信息，里面包含了方法名，参数等..."}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.2.2 对于一个注册协议，将传入的rpc-service实例注册在common.ServiceMap"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/b4/b4edc3f7f21f8b42a6effaed1d402cde.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这个Register函数将服务实例注册了两次，一次是以Interface为key写入接口服务组内，一次是以interface和proto为key写入特定的一个唯一的服务。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"后续会从common.Map里面取出来这个实例。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.2.3 获取默认代理工厂，将实例封装入代理invoker"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// 拿到一个proxyInvoker，这个invoker的url是传入的regUrl，这个地方将上面注册的service实例封装成了invoker\n// 这个GetProxyFactory返回的默认是common/proxy/proxy_factory/default.go\n// 这个默认工厂调用GetInvoker获得默认的proxyInvoker，保存了当前注册url\ninvoker := extension.GetProxyFactory(providerConfig.ProxyFactory).GetInvoker(*regUrl)\n// 暴露出来 生成exporter,开启tcp监听\n// 这里就该跳到registry/protocol/protocol.go registryProtocol 调用的Export，将当前proxyInvoker导出\nexporter = c.cacheProtocol.Export(invoker)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这一步的GetProxyFactory(\"default\")方法获取默认代理工厂，通过传入上述构造的regUrl，将url封装入代理invoker。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"可以进入common/proxy/proxy_factory/default.go::ProxyInvoker.Invoke()函数里，看到对于common.Map取用为svc的部分，以及关于svc对应Method的实际调用Call的函数如下："}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/75/7551e09bcf873a8b2171b4e82a8f13f9.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"到这里，上面GetInvoker(*regUrl)返回的invoker即为proxy"},{"type":"text","marks":[{"type":"italic"}],"text":"invoker，他封装好了用户定义的rpc"},{"type":"text","text":"service，并将具体的调用逻辑封装入了Invoke函数内。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"blockquote","content":[{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"为什么使用Proxy_invoker来调用？"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我认为，通过这个proxy_invoke调用用户的功能函数，调用方式将更加抽象化，可以在代码中看到，通过ins和outs来定义入参和出参，将整个调用逻辑抽象化为invocation结构体，而将具体的函数名的选择，参数向下传递，reflect反射过程封装在invoke函数内，这样的设计更有利于之后远程调用。我认为这是dubbo Invoke调用链的设计思想。"}]}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此，实现了图中对应的部分："}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":3},"content":[{"type":"text","text":"2.3 registry协议在zkRegistry上暴露上面的proxy_invoker"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"上面，我们执行到了exporter = c.cacheProtocol.Export(invoker)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这里的cacheProtocol为一层缓存设计，对应到原始的demo上，这里是默认实现好的registryProtocol"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"registry/protocol/protocol.go:: Export()"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这个函数内构造了多个EventListener，非常有java的设计感。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我们只关心服务暴露的过程，先忽略这些监听器。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.3.1 获取注册url和服务url"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/08/083ed9be0fd435e414d48b6d0623a0a9.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.3.2 获取注册中心实例zkRegistry"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/8d/8df22189b6679eae919f7139af4e3690.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"一层缓存操作，如果cache没有需要从common里面重新拿zkRegistry"}]},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.3.3 zkRegistry调用Registry方法，在zookeeper上注册dubboPath"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"上述拿到了具体的zkRegistry实例，该实例的定义在"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"registry/zookeeper/registry.go"}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/f2/f2ed0f8a04a434074cdfb825123662cf.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"该结构体组合了registry.BaseRegistry结构，base结构定义了注册器基础的功能函数，比如Registry、Subscribe等，但在这些默认定义的函数内部，还是会调用facade层（zkRegistry层）的具体实现函数，这一设计模型能在保证已有功能函数不需要重复定义的同时，引入外层函数的实现，类似于结构体继承却又复用了代码。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这一设计模式我认为值得学习。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"我们查看上述registry/protocol/protocol.go:: Export()函数，直接调用了:"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// 1. 通过zk注册器，调用Register()函数，将已有@root@rawurl注册到zk上\n\terr := reg.Register(*registeredProviderUrl)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"将已有RegistryUrl注册到了zkRegistry上。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这一步调用了baseRegistry的Register函数，进而调用zkRegister的DoRegister函数，进而调用："}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/67/67b793a6cfae4f082c4fb39734cdd5fc.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"在这个函数里，将对应root创造一个新的节点"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/29/2919ac7fc349afb08d6f2fb3aeef24df.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"并且写入具体node信息，node为url经过encode的结果，"},{"type":"text","marks":[{"type":"strong"}],"text":"包含了服务端的调用方式。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"这部分的代码较为复杂，具体可以看baseRegistry的 "},{"type":"link","attrs":{"href":"https://github.com/apache/dubbo-go/blob/811f4f1a2dcc75b4294f62cb795da0f3f399be93/registry/base_registry.go#L243","title":""},"content":[{"type":"text","text":"processURL()函数"}]},{"type":"text","text":"。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此，将服务端调用url注册到了zookeeper上，而客户端如果想获取到这个url，只需要传入特定的dubboPath，向zk请求即可。目前client是可以获取到访问方式了，但服务端的特定服务还没有启动，还没有开启特定协议端口的监听，这也是registry/protocol/protocol.go:: Export()函数接下来要做的事情："}]},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.3.4 proxy"},{"type":"text","marks":[{"type":"italic"}],"text":"invoker 封装入wrapped"},{"type":"text","text":"invoker，得到filter调用链"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// invoker封装入warppedInvoker\nwrappedInvoker := newWrappedInvoker(invoker, providerUrl)\n// 经过为invoker增加filter调用链，再使用dubbo协议Export，开启service并且返回了Exporter 。\n// export_1\ncachedExporter = extension.GetProtocol(protocolwrapper.FILTER).Export(wrappedInvoker)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"新建一个WrappedInvoker，用于之后链式调用"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"拿到提前实现并注册好的ProtocolFilterWrapper，调用Export方法，进一步暴露。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"protocol/protocolwrapped/protocol"},{"type":"text","marks":[{"type":"italic"}],"text":"filter"},{"type":"text","text":"wrapper.go:Export()"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/b4/b4b1d50cb0e9475d16073263a4e09fd5.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"protocol/protocolwrapped/protocol"},{"type":"text","marks":[{"type":"italic"}],"text":"filter"},{"type":"text","text":"wrapper.go:buildInvokerChain"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/dd/ddbe7ca0ec13c69c31e09ceb07ad38d6.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"可见，根据配置的内容，通过链式调用的构造，层层将proxy_invoker包裹在调用链的最底部，最终返回一个调用链invoker。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"对应图中部分："}]},{"type":"image","attrs":{"src":"https://static001.geekbang.org/infoq/3d/3ddce878a3e356b288234c9024a58a9e.png","alt":null,"title":"","style":[{"key":"width","value":"100%"},{"key":"bordertype","value":"none"}],"href":"","fromPaste":false,"pastePass":false}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"至此，我们已经拿到filter调用链，期待将这个chain暴露到特定端口，用于相应请求事件"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"heading","attrs":{"align":null,"level":4},"content":[{"type":"text","text":"2.3.5 通过dubbo协议暴露wrapped_invoker"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"protocol/protocolwrapped/protocol"},{"type":"text","marks":[{"type":"italic"}],"text":"filter"},{"type":"text","text":"wrapper.go:Export()"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"codeblock","attrs":{"lang":"go"},"content":[{"type":"text","text":"// 通过dubbo协议Export dubbo_protocol调用的 export_2\n\treturn pfw.protocol.Export(invoker)"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null}},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"回到上述Export函数的最后一行，调用了dubboProtocol的Export方法，将上述chain真正暴露。"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"该Export方法的具体实现在"}]},{"type":"paragraph","attrs":{"indent":0,"number":0,"align":null,"origin":null},"content":[{"type":"text","text":"protocol/dubbo/dubbo_protocol.go: 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