gRPC transport in NestJS - Mini Project: Build & Apply

Building a Simple gRPC Service with NestJS

📖 Scenario: You are creating a small service that uses gRPC to communicate between a client and a server. This service will greet users by their name.

🎯 Goal: Build a NestJS gRPC service that receives a name and returns a greeting message.

📋 What You'll Learn

Create a protobuf file defining the greeting service and messages

Configure NestJS to use gRPC transport with the protobuf

Implement the service method to return a greeting

Set up the main application to start the gRPC server

💡 Why This Matters

🌍 Real World

gRPC is used in microservices to enable fast, efficient communication between services, especially in distributed systems.

💼 Career

Understanding how to build and configure gRPC services with NestJS is valuable for backend developers working with modern microservice architectures.

1

Create the protobuf file for the greeting service

Create a file named hero.proto with a package named hero. Define a service called HeroService with an RPC method SayHello that takes a HelloRequest message and returns a HelloReply message. The HelloRequest message should have a string field name. The HelloReply message should have a string field message.

NestJS

// Create hero.proto file with package, service, and messages
// Your code here

Need a hint?

Remember to use syntax = "proto3"; at the top and define the package and service exactly as described.

2

Configure NestJS to use gRPC transport

In your main.ts file, import NestFactory and Transport from @nestjs/microservices. Create a microservice using NestFactory.createMicroservice with transport: Transport.GRPC and options specifying the package as hero and the protoPath as the path to hero.proto. Then start the microservice.

NestJS

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

async function bootstrap() {
  // Create microservice with gRPC transport
  // Your code here
}

bootstrap();

Need a hint?

Use join(__dirname, './hero.proto') to set the protoPath and specify transport: Transport.GRPC.

3

Implement the HeroService with SayHello method

Create a service class named HeroService with a method sayHello that takes an object with a name property and returns an object with a message property. The message should be `Hello, ${name}!`. Export this service and add it to the providers array in AppModule.

NestJS

import { Injectable } from '@nestjs/common';

@Injectable()
export class HeroService {
  // Implement sayHello method
  // Your code here
}

// Add HeroService to AppModule providers
// Your code here

Need a hint?

Use @Injectable() on the service and return the greeting message using a template string.

4

Complete the gRPC server setup and run

Ensure the main.ts file imports AppModule and starts the microservice with gRPC transport as configured. The server should listen for incoming gRPC requests using the HeroService implementation.

NestJS

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

async function bootstrap() {
  // Start the gRPC microservice
  // Your code here
}

bootstrap();

Need a hint?

Combine the service and main bootstrap code to run the gRPC server.