Kitex微服务开发实践：ETCD服务注册

灰太狼 2024-03-23 00:11 111阅读 0赞

服务注册通常用于分布式系统或微服务架构中，是一种用于管理和发现这些分布式服务的机制。它的目标是让服务能够动态地找到其他服务，并能够与其进行通信，而无需显式地配置其位置信息

本文简单讲述使用etcd进行服务注册，基于kitex和hertz框架简单实现微服务应用

代码地址：[https://github.com/T4t4KAU/Documents/tree/main/etcd-test][https_github.com_T4t4KAU_Documents_tree_main_etcd-test]

### 接口定义 ###

使用thrift编写如下idl

add.thrift

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>namespace go api</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>struct AddRequest { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>1: i32 first</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>2: i32 second</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>struct AddResponse { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>1: i32 sum</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>service AddService { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>AddResponse Add(AddRequest req)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

echo.thrift

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>namespace go api</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>struct EchoRequest { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>1: string message</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>struct EchoResponse { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>2: string message</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>service EchoService { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>EchoResponse Echo(1:EchoRequest req)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

使用Kitex生成代码(此处不作赘述):

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>.</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── add</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── handler.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── main.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── build.sh</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── echo</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── handler.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── main.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── go.mod</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── go.sum</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── idl</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── add.thrift</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── echo.thrift</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── kitex_gen</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── api</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── add.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── addservice</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── addservice.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── client.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── invoker.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; └── server.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── echo.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── echoservice</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── client.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── echoservice.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── invoker.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; └── server.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── k-add.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── k-consts.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── k-echo.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── kitex_info.yaml</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>└── script</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>└── bootstrap.sh</code></td> 
  </tr> 
 </tbody> 
</table>

echo服务将参数message原样返回，add服务将参数中的两个整数求和后返回

### 代码实现 ###

首先实现一个无服务注册的版本，在上述生成代码的基础上完善方法实现:

add/hander.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>// Add implements the AddServiceImpl interface.</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func (s *AddServiceImpl) Add(ctx context.Context, req *api.AddRequest) (resp *api.AddResponse, err error) { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp = new(api.AddResponse)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp.Sum = req.First + req.Second</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>return</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

add/main.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// 服务地址</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:9091")</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>svr := api.NewServer(new(AddServiceImpl),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServerBasicInfo(&amp;rpcinfo.EndpointBasicInfo{ServiceName: "add"}),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServiceAddr(addr),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>err := svr.Run()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>log.Println(err.Error())</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

echo/handler.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>// Echo implements the EchoServiceImpl interface.</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func (s *EchoServiceImpl) Echo(ctx context.Context, req *api.EchoRequest) (resp *api.EchoResponse, err error) { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp = new(api.EchoResponse)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp.Message = req.Message</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>return</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

echo/main.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// 服务地址</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:9092")</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>svr := api.NewServer(new(EchoServiceImpl),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServerBasicInfo(&amp;rpcinfo.EndpointBasicInfo{ServiceName: "echo"}),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServiceAddr(addr),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>err := svr.Run()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>log.Println(err.Error())</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

创建一个api包，作为两个服务的API网关，使用hertz来处理用户请求

目录结构：

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>.</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── add</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── handler.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── main.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── api</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── add.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── echo.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── main.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── build.sh</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── echo</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── handler.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── main.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── go.mod</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── go.sum</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── idl</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── add.thrift</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── echo.thrift</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── kitex_gen</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── api</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── add.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── addservice</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── addservice.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── client.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── invoker.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; └── server.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── echo.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── echoservice</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── client.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── echoservice.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; ├── invoker.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; │&nbsp;&nbsp; └── server.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── k-add.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; ├── k-consts.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>│&nbsp;&nbsp; └── k-echo.go</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>├── kitex_info.yaml</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>└── script</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>└── bootstrap.sh</code></td> 
  </tr> 
 </tbody> 
</table>

实现web handler函数，在handler中使用RPC请求服务

add:

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>var addClient addservice.Client</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func AddHandler(ctx context.Context, c *app.RequestContext) { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>num1, _ := strconv.Atoi(c.Query("first"))</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>num2, _ := strconv.Atoi(c.Query("second"))</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// RPC请求</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp, err := addClient.Add(ctx, &amp;api.AddRequest{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>First: int32(num1), Second: int32(num2),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>c.JSON(http.StatusInternalServerError, utils.H{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>"message": err.Error(),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>return</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>c.JSON(http.StatusOK, utils.H{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>"message": resp.Sum,</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

echo:

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>var echoClient echoservice.Client</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func EchoHandler(ctx context.Context, c *app.RequestContext) { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// RPC请求</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>resp, err := echoClient.Echo(ctx, &amp;api.EchoRequest{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>Message: c.Query("message"),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>c.JSON(http.StatusInternalServerError, utils.H{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>"message": err.Error(),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>c.JSON(http.StatusOK, utils.H{ </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>"message": resp.Message,</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

在主调函数中进行RPC客户端初始化和路由注册:

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func Init() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>var err error</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addClient, err = addservice.NewClient("addservice",</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>client.WithHostPorts("127.0.0.1:9091"))</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>echoClient, err = echoservice.NewClient("echoservice",</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>client.WithHostPorts("127.0.0.1:9092"))</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>Init()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r := server.Default()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.POST("/add", AddHandler)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.GET("/echo", EchoHandler)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.Spin()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

启动add和echo服务，再启动api，请求URL即可访问，此处省略测试过程

### 引入服务注册 ###

在上述实现中，要显式的告诉API网关服务的地址，一旦这个地址发生变化，会导致服务不可用，接下来使用服务注册

使用docker启动etc:

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>docker run -d -p 10079:2379 --name etcd \</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>-e ETCD_LISTEN_CLIENT_URLS=http://0.0.0.0:2379 \</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>-e ETCD_ADVERTISE_CLIENT_URLS=http://0.0.0.0:2379 \</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>-e ETCDCTL_API=3 \</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>quay.io/coreos/etcd:v3.5.5</code></td> 
  </tr> 
 </tbody> 
</table>

etcd服务器启动在10079端口

接下来修改服务代码：

add/main.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// 服务注册</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r, err := etcd.NewEtcdRegistry([]string{"127.0.0.1:10079"})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:9091")</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>svr := api.NewServer(new(AddServiceImpl),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServerBasicInfo(&amp;rpcinfo.EndpointBasicInfo{ServiceName: "add"}), // 指定服务名称</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServiceAddr(addr),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithRegistry(r), // 设置服务注册</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>err = svr.Run()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>log.Println(err.Error())</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

echo/main.go

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>// 服务注册</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r, err := etcd.NewEtcdRegistry([]string{"127.0.0.1:10079"})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:9092")</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>svr := api.NewServer(new(EchoServiceImpl),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServerBasicInfo(&amp;rpcinfo.EndpointBasicInfo{ServiceName: "echo"}), // 指定服务名称</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithServiceAddr(addr),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>server.WithRegistry(r), // 设置服务注册</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>err = svr.Run()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>log.Println(err.Error())</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

修改api代码，无须给出两个服务的地址了:

<table> 
 <tbody> 
  <tr> 
   <td></td> 
   <td><code>package main</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func Init() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>var err error</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r, err := etcd.NewEtcdResolver([]string{"127.0.0.1:10079"})</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>addClient, err = addservice.NewClient("add",</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>client.WithResolver(r),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>echoClient, err = echoservice.NewClient("echo",</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>client.WithResolver(r),</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>if err != nil { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>panic(err)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>func main() { </code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>Init()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r := server.Default()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.POST("/add", AddHandler)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.GET("/echo", EchoHandler)</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>r.Spin()</code></td> 
  </tr> 
  <tr> 
   <td></td> 
   <td><code>}</code></td> 
  </tr> 
 </tbody> 
</table>

启动之后，服务正常使用

[https_github.com_T4t4KAU_Documents_tree_main_etcd-test]: https://github.com/T4t4KAU/Documents/tree/main/etcd-test