Java客户端连接AWS EKS上容器化gRPC服务的教程

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// 定义一个 Greeter 服务
service Greeter {
  // 定义一个 SayHello 方法，接收 HelloRequest 并返回 HelloReply
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// 定义请求消息
message HelloRequest {
  string name = 1;
}

// 定义响应消息
message HelloReply {
  string message = 1;
}

<build>
    <extensions>
        <extension>
            <groupId>kr.motd.maven</groupId>
            <artifactId>os-maven-plugin</artifactId>
            <version>1.7.1</version>
        </extension>
    </extensions>
    <plugins>
        <plugin>
            <groupId>org.xolstice.maven.plugins</groupId>
            <artifactId>protobuf-maven-plugin</artifactId>
            <version>0.6.1</version>
            <configuration>
                <protocArtifact>com.google.protobuf:protoc:3.25.1:exe:${os.detected.classifier}</protocArtifact>
                <pluginId>grpc-java</pluginId>
                <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.62.2:exe:${os.detected.classifier}</pluginArtifact>
                <protoSourceRoot>src/main/proto</protoSourceRoot> <!-- .proto文件存放路径 -->
            </configuration>
            <executions>
                <execution>
                    <goals>
                        <goal>compile</goal>
                        <goal>compile-custom</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

<dependencies>
    <dependency>
        <groupId>io.grpc</groupId>
        <artifactId>grpc-netty-shaded</artifactId>
        <version>1.62.2</version>
    </dependency>
    <dependency>
        <groupId>io.grpc</groupId>
        <artifactId>grpc-protobuf</artifactId>
        <version>1.62.2</version>
    </dependency>
    <dependency>
        <groupId>io.grpc</groupId>
        <artifactId>grpc-stub</artifactId>
        <version>1.62.2</version>
    </dependency>
    <dependency>
        <groupId>javax.annotation</groupId>
        <artifactId>javax.annotation-api</artifactId>
        <version>1.3.2</version>
    </dependency>
</dependencies>

package io.grpc.examples.helloworld;

import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

public class HelloWorldClient {
    private static final Logger logger = Logger.getLogger(HelloWorldClient.class.getName());

    private final ManagedChannel channel;
    private final GreeterGrpc.GreeterBlockingStub blockingStub;

    /** 构建客户端，连接到指定主机和端口 */
    public HelloWorldClient(String host, int port) {
        this(ManagedChannelBuilder.forAddress(host, port)
                // 生产环境中应配置TLS/SSL
                .usePlaintext() 
                .build());
    }

    HelloWorldClient(ManagedChannel channel) {
        this.channel = channel;
        blockingStub = GreeterGrpc.newBlockingStub(channel);
    }

    public void shutdown() throws InterruptedException {
        channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
    }

    /** 向 Greeter 服务发送 SayHello 请求 */
    public void greet(String name) {
        logger.info("Will try to greet " + name + " ...");
        HelloRequest request = HelloRequest.newBuilder().setName(name).build();
        HelloReply response;
        try {
            response = blockingStub.sayHello(request);
        } catch (StatusRuntimeException e) {
            logger.log(Level.WARNING, "RPC failed: {0}", e.getStatus());
            return;
        }
        logger.info("Greeting: " + response.getMessage());
    }

    public static void main(String[] args) throws Exception {
        // 服务的IP地址和端口，这里需要替换为EKS中gRPC服务的实际可访问地址
        String host = "localhost"; // 示例，实际应为EKS服务的IP或域名
        int port = 50051; // 示例，实际应为gRPC服务监听的端口

        // 如果通过命令行参数传入，则使用命令行参数
        if (args.length > 0) {
            host = args[0];
        }
        if (args.length > 1) {
            port = Integer.parseInt(args[1]);
        }

        HelloWorldClient client = new HelloWorldClient(host, port);
        try {
            String user = "world";
            if (args.length > 2) {
                user = args[2];
            }
            client.greet(user);
        } finally {
            client.shutdown();
        }
    }
}

apiVersion: v1
kind: Service
metadata:
  name: my-grpc-service
  namespace: default
spec:
  selector:
    app: my-grpc-app # 匹配gRPC服务Pod的标签
  ports:
    - protocol: TCP
      port: 50051 # Service端口
      targetPort: 50051 # Pod内部监听端口
  type: LoadBalancer # 暴露为AWS Load Balancer

// Java客户端连接代码
String host = "your-elb-dns-name.us-east-1.elb.amazonaws.com"; // 替换为实际的ELB DNS名称
int port = 50051;
HelloWorldClient client = new HelloWorldClient(host, port);