无法通过Postman向NestJS gRPC服务器发起请求的问题排查

我搭建了一台处理gRPC请求的NestJS服务器，用Postman临时调试时始终返回错误：

Received RST_STREAM with code 2 triggered by internal client error: Protocol error

服务器部署在远程机器，通过SSH隧道发送请求，未设置认证。查看服务器日志发现控制器的createLog函数完全未被触发。用grpcurl测试也失败，报错：

Failed to dial target host "localhost:6666": context deadline exceeded

相关代码 #

app.controller.ts #

import { Metadata, ServerUnaryCall } from '@grpc/grpc-js';
import { Controller } from '@nestjs/common';
import { GrpcMethod } from '@nestjs/microservices';
import { BaseLoggingService } from './common/baseLogging.service';
import { CreateLogRequest, CreateLogResponse } from './generated/logs';

@Controller()
export class AppController {
  constructor(private baseLoggingService: BaseLoggingService) {}

  @GrpcMethod('LogService', 'CreateLog')
  async createLog(
    req: CreateLogRequest,
    metadata: Metadata,
    call: ServerUnaryCall<CreateLogRequest, CreateLogResponse>,
  ): Promise<CreateLogResponse> {
    return await this.baseLoggingService.createLog(req);
  }
}

.proto定义文件 #

CreateLogRequest和CreateLogResponse接口由protobuf-ts插件生成，基于以下.proto文件：

/**
* Definitions of shared interfaces 
**/

syntax = "proto3";

package logs;

enum LogLevel {
  INFO = 0;
  WARN = 1;
  ERROR = 2;
  DEBUG = 3;
}

message LogContext {
  string sessionId = 1;
  string requestId = 2;
  string hostname = 3;
  string podName = 4;
  string grpcMethodName = 5;
  uint32 durationMs = 6;
}

message ErrorData {
  string name = 1;
  string notificationCode = 2;
  string stack = 3;
}

message CreateLogRequest {
  LogLevel level = 1;
  string service = 2;
  int32 timestamp = 3;
  string message = 4;
  LogContext context = 5;
  ErrorData errorData = 6;
}

message CreateLogResponse {
  LogLevel level = 1;
  string service = 2;
  int32 code = 3;
}

service LogService {
  rpc CreateLog (CreateLogRequest) returns (CreateLogResponse) {}
}

grpcurl测试命令及错误 #

grpcurl -plaintext -d '{
    "context": {
        "durationMs": 4100079420,
        "grpcMethodName": "magna ut commodo",
        "hostname": "exercitation dolor",
        "podName": "ad Duis non",
        "requestId": "do",
        "sessionId": "nostrud"
    },
    "errorData": {
        "name": "nostrud enim Lorem consectetur",
        "notificationCode": "in anim",
        "stack": "incididunt"
    },
    "level": 0,
    "message": "eu qui dolore laborum eiusmod",
    "service": "sunt",
    "timestamp": -499959849
}' localhost:6666 LogService/CreateLog

报错：

Failed to dial target host "localhost:6666": context deadline exceeded

排查与解决步骤 #

1. 检查SSH隧道连通性

   • 用telnet localhost 6666测试本地端口是否能连通，若不通则重新建立隧道，确保端口映射正确（示例：ssh -L 6666:localhost:50051 user@remote-server，需对应远程gRPC服务的监听端口）。

2. 修正服务器监听配置

   • 确认NestJS启动时gRPC服务绑定0.0.0.0而非仅localhost，否则远程机器无法访问：

     async function bootstrap() {
       const app = await NestFactory.createMicroservice(AppModule, {
         transport: Transport.GRPC,
         options: {
           package: 'logs',
           protoPath: join(__dirname, './logs.proto'),
           url: '0.0.0.0:50051', // 绑定所有网卡
         },
       });
       await app.listen();
     }
     bootstrap();
     

3. 调整Postman请求参数

   • 选择gRPC协议，地址填localhost:6666并勾选Plaintext；
   • 确保请求参数符合proto定义：比如durationMs是uint32类型，值不能超过4294967295，避免参数解析错误。

4. 优化grpcurl调用

   • 通过-proto参数指定本地proto文件路径，避免服务端反射问题：

     grpcurl -plaintext -proto ./logs.proto -d '{...}' localhost:6666 LogService/CreateLog
     

5. 检查服务器防火墙

   • 确认远程服务器防火墙允许gRPC监听端口（如50051）的入站连接，避免端口被拦截。

内容的提问来源于stack exchange，提问作者Imperator Romanorum