nest使用grpc实现微服务

首先下载依赖

    "@grpc/grpc-js": "^1.13.4",
    "@grpc/proto-loader": "^0.7.15",
    "@nestjs/common": "^11.0.1",
    "@nestjs/core": "^11.0.1",
    "@nestjs/microservices": "^11.0.1",
    "@nestjs/platform-express": "^11.0.1",
    "reflect-metadata": "^0.2.2",
    "rxjs": "^7.8.1"

然后先新建一个proto文件

syntax="proto3";

package hello;

service HelloService{
    rpc SayHello(HelloRequest)returns(HelloResponse){}
}

message HelloRequest{
    string name=1;
}

message HelloResponse{
    string message=1;
}

然后在main.ts中创建微服务

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { MicroserviceOptions, Transport } from '@nestjs/microservices';

async function bootstrap() {
  const app = await NestFactory.createMicroservice<MicroserviceOptions>(
    AppModule,
    {
      transport: Transport.GRPC,
      options: {
        url: '0.0.0.0:50051',
        package: 'hello',
        protoPath: 'hello.proto',
      },
    },
  );
  await app.listen();
}
bootstrap();

然后在controller中使用GrpcMethod装饰器装饰需要调用的方法

import { Controller, Get } from '@nestjs/common';
import { AppService } from './app.service';
import { GrpcMethod } from '@nestjs/microservices/decorators';

@Controller()
export class AppController {
  constructor(private readonly appService: AppService) {}

  @GrpcMethod('HelloService', 'SayHello')
  getHello(data) {
    console.log(data);
    return { message: 'hello' };
  }
}

至此服务端就写完了。

接下来是客户端，依赖也是相同的。

首先在app.module.ts中注册grpc服务

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { ClientsModule, Transport } from '@nestjs/microservices';

@Module({
  imports: [
    ClientsModule.register([
      {
        name: 'HELLO',
        transport: Transport.GRPC,
        options: {
          url: '0.0.0.0:50051',
          package: 'hello',
          protoPath: 'hello.proto',
        },
      },
    ]),
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

然后就可以在controller中注入service，service中再注入ClientGrpc的实例

import { Injectable, Inject } from '@nestjs/common';
import { ClientGrpc } from '@nestjs/microservices';
import { firstValueFrom } from 'rxjs';

interface HelloService {
  SayHello(data: { name: string }): any;
}

@Injectable()
export class AppService {
  constructor(@Inject('HELLO') private client: ClientGrpc) {}

  onModuleInit() {}

  getHello(): string {
    let res = this.client
      .getService<HelloService>('HelloService')
      .SayHello({ name: 'cc' });
    firstValueFrom(res).then((val) => {
      console.log(val);
    });
    return 'Hello World!';
  }
}