gRPC Module Documentation

Introduction

The gRPC module provides a powerful and flexible way to build gRPC servers and clients within your application. It leverages the gRPC protocol to enable efficient, low-latency communication between services using protocol buffers.

This module is designed to integrate seamlessly with your application, providing decorators and utilities to define gRPC services, methods, and clients with ease.

Overview

GrpcModule

The GrpcModule is the core module that you import into your application to enable gRPC functionality. It provides configuration options to set up gRPC servers and clients.

GrpcServer

GrpcServer is the server implementation that listens for incoming gRPC requests and dispatches them to the appropriate service methods.

GrpcClient

GrpcClient is the client implementation used to connect to remote gRPC servers and invoke their methods.

Decorators

• @GrpcService: Decorates a class to define it as a gRPC service.
• @GrpcMethod: Decorates a method within a service class to define it as a gRPC method.
• @InjectGrpcClient: Decorator to inject a configured gRPC client instance into your service or controller.

Basic Usage Example

Below is a basic example demonstrating how to set up a gRPC server and client.

Server Setup (Referencing examples/src/grpc/server.ts)

import { GrpcModule, GrpcService, GrpcMethod } from '@yourorg/grpc';

@GrpcService()
class HeroService {
  @GrpcMethod('FindOne')
  findOne(data: { id: number }) {
    return { id: data.id, name: 'Hero ' + data.id };
  }
}

const grpcModule = GrpcModule.forRoot({
  server: {
    port: 50051,
  },
  clients: [],
});

// Application bootstrap code to start the server

Client Setup (Referencing examples/src/grpc/client.ts)

import { GrpcModule, InjectGrpcClient, GrpcClient } from '@yourorg/grpc';

class HeroClientService {
  
  constructor(@InjectGrpcClient('hero') private client: GrpcClient)

  async findOne(id: number) {
    return this.client.send('HeroService.FindOne', { id });
  }
}

const grpcModule = GrpcModule.forRoot({
  clients: [
    {
      name: 'hero',
      url: 'localhost:50051',
    },
  ],
});

// Application bootstrap code to start the client

Module Configuration

The GrpcModule can be configured using the forRoot method, which accepts an options object.

Options

• server: Configuration for the gRPC server.

  • port: The port number on which the server listens.
  • Additional server options can be provided as needed.

• clients: An array of client configurations.

  • Each client configuration includes:
    • name: A unique identifier for the client.
    • url: The address of the gRPC server to connect to.
    • Additional client options can be provided.

Example:

GrpcModule.forRoot({
  server: {
    port: 50051,
  },
  clients: [
    {
      name: 'hero',
      url: 'localhost:50051',
    },
  ],
});

This setup allows you to run a gRPC server and connect clients to it within the same application or across different services.

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For more detailed examples and advanced usage, please refer to the example files in the examples/src/grpc folder.