java版gRPC实战之七(基于eureka的注册发现)

弱龄寄事外,委怀在琴书。这篇文章主要讲述java版gRPC实战之七:基于eureka的注册发现相关的知识,希望能为你提供帮助。
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名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) git@github.com:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议
  • 这个git项目中有多个文件夹,《java版gRPC实战》系列的源码在==grpc-tutorials==文件夹下,如下图红框所示:
    java版gRPC实战之七(基于eureka的注册发现)

    文章图片
  • ==grpc-tutorials==文件夹下有多个目录,本篇文章对应的eureka代码在==cloud-eureka==目录,服务端代码在==cloud-server-side==目录,客户端代码在==cloud-client-side==目录,如下图:
    java版gRPC实战之七(基于eureka的注册发现)

    文章图片
    eureka应用开发
  • 在父工程grpc-turtorials下面新建名为==cloud-eureka==的模块,其build.gradle内容如下:
    // 使用springboot插件 plugins id org.springframework.boot

dependencies
implementation org.springframework.boot:spring-boot-starter
// 依赖eureka
implementation org.springframework.cloud:spring-cloud-starter-netflix-eureka-server
// 状态暴露需要的依赖
implementation org.springframework.boot:spring-boot-starter-actuator
// 依赖自动生成源码的工程
implementation project(:grpc-lib)

- 配置文件bootstrap.yml,设置自己的web端口号和应用名,另外eureka.client.serviceUrl.defaultZone的配置请改成自己的IP: ```yml server: port: 8085spring: application: name: cloud-eurekaeureka: instance: hostname: localhost prefer-ip-address: true status-page-url-path: /actuator/info health-check-url-path: /actuator/health lease-expiration-duration-in-seconds: 30 lease-renewal-interval-in-seconds: 30 client: registerWithEureka: false fetchRegistry: false serviceUrl: defaultZone: http://192.168.50.5:8085/eureka/ server: enable-self-preservation: falseendpoints: shutdown: enabled: true

  • 这个模块只有一个类CloudEurekaApplication.java:
    package com.bolingcavalry.grpctutorials;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@EnableEurekaServer@SpringBootApplication
br/>@SpringBootApplication
public static void main(String[] args) SpringApplication.run(CloudEurekaApplication.class, args);


- 以上就是一个简单通用的eureka服务了; ### gRPC服务端开发 - 依赖eureka的gRPC服务端,其重点在于:第一,配置使用eureka,第二,不要指定端口; - 在父工程grpc-turtorials下面新建名为==cloud-server-side==的模块,其build.gradle内容如下,注意要引入gRPC服务端相关的starter: ```groovy // 使用springboot插件 plugins id org.springframework.bootdependencies implementation org.projectlombok:lombok implementation org.springframework.boot:spring-boot-starter-web implementation org.springframework.boot:spring-boot-starter // 作为gRPC服务提供方,需要用到此库 implementation net.devh:grpc-server-spring-boot-starter // 作为eureka的client implementation org.springframework.cloud:spring-cloud-starter-netflix-eureka-client // 状态暴露需要的依赖 implementation org.springframework.boot:spring-boot-starter-actuator // 依赖自动生成源码的工程 implementation project(:grpc-lib) // annotationProcessor不会传递,使用了lombok生成代码的模块,需要自己声明annotationProcessor annotationProcessor org.projectlombok:lombok

  • 配置文件application.yml,设置自己的应用名,另外值得注意的是==server.port==和==grpc.server.port==这两个配置的值都是0,这样两个端口就会被自动分配未被占用的值:
    spring: application: name: cloud-server-side

server:
port: 0
grpc:
server:
port: 0
eureka:
instance:
prefer-ip-address: true
instanceId: $spring.application.name:$vcap.application.instance_id:$spring.application.instance_id:$random.value
client:
register-with-eureka: true
fetch-registry: true
service-url:
defaultZone: http://192.168.50.5:8085/eureka/
- 启动类CloudServerSideApplication.java: ```java package com.bolingcavalry.grpctutorials; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.eureka.EnableEurekaClient; @EnableEurekaClient @EnableDiscoveryClient @SpringBootApplication public class CloudServerSideApplication public static void main(String[] args) SpringApplication.run(CloudServerSideApplication.class, args);

  • 提供gRPC服务的类GrpcServerService,和local-server模块中的一样:
    package com.bolingcavalry.grpctutorials;

import com.bolingcavalry.grpctutorials.lib.HelloReply;
import com.bolingcavalry.grpctutorials.lib.SimpleGrpc;
import net.devh.boot.grpc.server.service.GrpcService;
import java.util.Date;
@GrpcService
public class GrpcServerService extends SimpleGrpc.SimpleImplBase
@Override public void sayHello(com.bolingcavalry.grpctutorials.lib.HelloRequest request, io.grpc.stub.StreamObserver< HelloReply> responseObserver) HelloReply reply = HelloReply.newBuilder().setMessage("1. Hello " + request.getName() + ", " + new Date()).build(); responseObserver.onNext(reply); responseObserver.onCompleted();


- 以上就是服务端代码了,可见除了将gRPC端口设置为0,以及常规使用eureka的配置,其他部分和local-server模块是一样的;### gRPC客户端开发 - 依赖eureka的gRPC客户端,其重点在于:第一,配置使用eureka,第二,配置中的gRPC配置项的名字要等于gRPC服务端在eureka注册的名字,如下图红框所示: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0e86ce566639.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 在父工程grpc-turtorials下面新建名为==cloud-client-side==的模块,其build.gradle内容如下,注意要引入gRPC客户端相关的starter: ```groovy // 使用springboot插件 plugins id org.springframework.bootdependencies implementation org.projectlombok:lombok implementation org.springframework.boot:spring-boot-starter-web implementation org.springframework.boot:spring-boot-starter // 作为gRPC服务使用方,需要用到此库 implementation net.devh:grpc-client-spring-boot-starter // 作为eureka的client implementation org.springframework.cloud:spring-cloud-starter-netflix-eureka-client // 状态暴露需要的依赖 implementation org.springframework.boot:spring-boot-starter-actuator // 依赖自动生成源码的工程 implementation project(:grpc-lib) // annotationProcessor不会传递,使用了lombok生成代码的模块,需要自己声明annotationProcessor annotationProcessor org.projectlombok:lombok

  • 配置文件application.yml,设置自己的web端口号,另外值得注意的是gRPC配置项==cloud-server-side==的名字要等于gRPC服务端在eureka注册的名字,并且==不需要address配置项==:
    server: port: 8086 spring: application: name: cloud-client-side eureka: instance: prefer-ip-address: true status-page-url-path: /actuator/info health-check-url-path: /actuator/health instanceId: $spring.application.name:$vcap.application.instance_id:$spring.application.instance_id:$random.value client: register-with-eureka: true fetch-registry: true service-url: defaultZone: http://192.168.50.5:8085/eureka/ grpc: client: # gRPC配置的名字,GrpcClient注解会用到 cloud-server-side: enableKeepAlive: true keepAliveWithoutCalls: true negotiationType: plaintext

  • 启动类CloudClientSideApplication.java,使用了eureka相关的注解:
    package com.bolingcavalry.grpctutorials;

【java版gRPC实战之七(基于eureka的注册发现)】import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@EnableEurekaClient@EnableDiscoveryClient
br/>@EnableDiscoveryClient
public class CloudClientSideApplication
public static void main(String[] args) SpringApplication.run(CloudClientSideApplication.class, args);


- 封装gRPC调用的服务类GrpcServerService,和local-server模块中的一样,GrpcClient注解对应配置中的gRPC配置项: ```java package com.bolingcavalry.grpctutorials; import com.bolingcavalry.grpctutorials.lib.HelloReply; import com.bolingcavalry.grpctutorials.lib.HelloRequest; import com.bolingcavalry.grpctutorials.lib.SimpleGrpc; import io.grpc.StatusRuntimeException; import net.devh.boot.grpc.client.inject.GrpcClient; import org.springframework.stereotype.Service; @Service public class GrpcClientService @GrpcClient("cloud-server-side") private SimpleGrpc.SimpleBlockingStub simpleStub; public String sendMessage(final String name) try final HelloReply response = this.simpleStub.sayHello(HelloRequest.newBuilder().setName(name).build()); return response.getMessage(); catch (final StatusRuntimeException e) return "FAILED with " + e.getStatus().getCode().name();

  • 再做一个web接口类,这样我们就能通过web调用验证gRPC服务了:
    package com.bolingcavalry.grpctutorials;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class GrpcClientController
@Autowired private GrpcClientService grpcClientService; @RequestMapping("/") public String printMessage(@RequestParam(defaultValue = "https://www.songbingjia.com/android/will") String name) return grpcClientService.sendMessage(name);


- 客户端开发完毕,接下来可以验证了; ### 验证 - 启动cloud-eureka: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0ea74f765779.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 启动cloud-server-side,可见gRPC服务端口自动分配了65141,不过我们无需关心这个值,因为客户端可以从eureka获取到: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0ebcd0456378.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 接下来启动cloud-client-side,启动成功后eureka上可见两个服务的注册信息: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0ec9c3c93251.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 浏览器访问cloud-client-side提供的web接口,响应如下,可见cloud-client-side成功调用了cloud-server-side的gRPC服务: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0ecaba477106.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) ### 一点疑惑 - 如果您对eureka有所了解,可能会产生一点疑惑:cloud-client-side从eureka取得的cloud-server-side信息,应该是http服务的地址和端口,不应该有gRPC的端口号,因为eureka的注册发现服务并不包含gRPC有关的! - 篇幅所限,这里不适合将上述问题展开分析,咱们来关注最核心的地方,相信聪明的您看上一眼就会豁然开朗; - DiscoveryClientNameResolver来自grpc-client-spring-boot-autoconfigure.jar,用来保存从eureka取得的服务端信息,该类的注释已经说得很清楚了,从metadata的gRPC.port配置项中取得gRPC端口号: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232358_61dafe0ec3a7988518.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 在DiscoveryClientNameResolver的代码中打上断点,查看成员变量instanceList,可见metadata中确实有gRPC端口的信息: ![在这里插入图片描述](https://s4.51cto.com/images/blog/202201/09232359_61dafe0f03bbb33626.png?x-oss-process=image/watermark,size_14,text_QDUxQ1RP5Y2a5a6i,color_FFFFFF,t_100,g_se,x_10,y_10,shadow_20,type_ZmFuZ3poZW5naGVpdGk=) - 至此,基于eureka的gRPC服务注册发现的开发和验证就完成了,希望本文可以给您带来一些参考,让您的服务在注册中心的加持下更加灵活和可靠;### 欢迎关注公众号:程序员欣宸 > 微信搜索「程序员欣宸」,我是欣宸,期待与您一同畅游Java世界...


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