Step1 Setup And Run

✅ Step 1: Setting Up nestjs-tutorial Monorepo

⚙️ 1. Install Nest CLI & Create Monorepo

First, install Nest CLI globally if you don’t already have it:

npm install -g @nestjs/cli

Verify version:

nest --version

Expected output (or higher):

11.0.10

Now create the project:

nest new nestjs-tutorial --package-manager npm
cd nestjs-tutorial

Choose npm when asked. This creates a clean NestJS workspace.

⚙️ 2. Generate Microservices (apps)

We’ll generate 5 apps inside /apps:

nest generate app api-gateway
nest generate app auth-service
nest generate app tenant-service
nest generate app user-service
nest generate app product-service

Updated structure:

nestjs-tutorial/
├── apps/
│   ├── api-gateway/
│   ├── auth-service/
│   ├── tenant-service/
│   ├── user-service/
│   └── product-service/

⚙️ 3. Generate Shared Libraries (libs)

Now create reusable libraries:

nest generate library auth-lib
nest generate library common-lib
nest generate library database-lib
nest generate library email-lib
nest generate library logger-lib
nest generate library redis-lib

Updated structure:

nestjs-tutorial/
├── libs/
│   ├── auth-lib/
│   ├── common-lib/
│   ├── database-lib/
│   ├── email-lib/
│   ├── logger-lib/
│   └── redis-lib/

⚙️ 4. Install Dependencies

We’ll need Mongoose, Redis, Winston, and validation libraries:

npm install @nestjs/mongoose mongoose
npm install @nestjs/microservices
npm install redis ioredis
npm install winston nest-winston
npm install @nestjs/config
npm install class-validator class-transformer
npm install -D @types/redis @types/uuid

⚙️ 5. Configure Explicit Ports & Logger

Update each service’s main.ts to use explicit ports with a logger context.

Example: apps/api-gateway/src/main.ts

import { NestFactory } from '@nestjs/core';
import { ApiGatewayModule } from './api-gateway.module';
import { Logger } from '@nestjs/common';

async function bootstrap() {
  const app = await NestFactory.create(ApiGatewayModule);
  const logger = new Logger('ApiGateway');
  const port = 3501; // HTTP port
  await app.listen(port);
  logger.log(`🚀 Api-Gateway is running on: http://localhost:${port}`);
}
bootstrap();

Example: apps/auth-service/src/main.ts

import { NestFactory } from '@nestjs/core';
import { Transport, MicroserviceOptions } from '@nestjs/microservices';
import { AuthServiceModule } from './auth-service.module';
import { Logger } from '@nestjs/common';

async function bootstrap() {
  const app = await NestFactory.createMicroservice<MicroserviceOptions>(
    AuthServiceModule,
    {
      transport: Transport.TCP,
      options: {
        host: '127.0.0.1',
        port: 4501, // TCP port
      },
    },
  );

  const logger = new Logger('AuthService');
  await app.listen();
  logger.log('🚀 Auth-Service TCP Microservice running on port 4501');
}
bootstrap();

👉 Do the same for tenant-service (4502), user-service (4503), and product-service (4504).

⚙️ 6. Custom Welcome Messages

Each service should have a clear welcome response for easy testing.

Example: apps/api-gateway/src/api-gateway.controller.ts

import { Controller, Get } from '@nestjs/common';

@Controller()
export class AppController {
  @Get()
  getHello(): any {
    return { message: '🚀 Welcome to Api Gateway!' };
  }
}

Apply similar in each service:

Service	Port	Message
api-gateway	3501	"🚀 Welcome to Api Gateway!"
auth-service	4501	"🔑 Welcome to Auth Service (TCP)!"
tenant-service	4502	"🏢 Welcome to Tenant Service (TCP)!"
user-service	4503	"👤 Welcome to User Service (TCP)!"
product-service	4504	"📦 Welcome to Product Service (TCP)!"

⚙️ 7. Verify Each Service

Run each service in a separate terminal:

npm run start:dev api-gateway
npm run start:dev auth-service
npm run start:dev tenant-service
npm run start:dev user-service
npm run start:dev product-service

Expected logs:

[Nest] 12345   LOG [ApiGateway] 🚀 Api-Gateway is running on: http://localhost:3501
[Nest] 12346   LOG [AuthService] 🚀 Auth-Service TCP Microservice running on port 4501
[Nest] 12347   LOG [TenantService] 🚀 Tenant-Service TCP Microservice running on port 4502
[Nest] 12348   LOG [UserService] 🚀 User-Service TCP Microservice running on port 4503
[Nest] 12349   LOG [ProductService] 🚀 Product-Service TCP Microservice running on port 4504

Verification in browser:

http://localhost:3501 → {"message":"🚀 Welcome to Api Gateway!"}

TCP services won’t show in browser (we’ll connect via Gateway later).

⚙️ 8. Dynamic Runner Script (Optional)

Instead of running each service in separate terminals, you can start all services dynamically with a single script. We won’t modify package.json; we’ll call the Nest CLI directly via npx.

Create Script

File: tools/run-all.sh

#!/usr/bin/env bash
# tools/run-all.sh
# ------------------------------------------------------------
# Starts all NestJS services in watch mode (in parallel)
# ------------------------------------------------------------

set -e  # Exit on first error

# List of Nest projects (as created by `nest g app ...`)
SERVICES=(
  api-gateway
  auth-service
  tenant-service
  product-service
  user-service
)

# Start each service in the background using Nest CLI directly
for SERVICE in "${SERVICES[@]}"; do
  echo "▶︎ Starting $SERVICE..."
  npx nest start "$SERVICE" --watch &
done

# Trap Ctrl+C and stop all background jobs
trap 'echo; echo "🛑 Stopping all services..."; kill 0' SIGINT

# Wait for all background jobs
wait

Make it executable:

chmod +x tools/run-all.sh

Run & Verify

From repo root:

./tools/run-all.sh

Expected trimmed output:

▶︎ Starting api-gateway...
▶︎ Starting auth-service...
▶︎ Starting tenant-service...
▶︎ Starting product-service...

[Nest] 18438  - 09/11/2025, 1:05:14 PM     LOG [NestFactory] Starting Nest application...
[Nest] 18439  - 09/11/2025, 1:05:14 PM     LOG [NestFactory] Starting Nest application...
[Nest] 18440  - 09/11/2025, 1:05:14 PM     LOG [NestFactory] Starting Nest application...
[Nest] 18438  - 09/11/2025, 1:05:14 PM     LOG [InstanceLoader] TenantServiceModule dependencies initialized +17ms
[Nest] 18440  - 09/11/2025, 1:05:14 PM     LOG [InstanceLoader] ProductServiceModule dependencies initialized +18ms
[Nest] 18439  - 09/11/2025, 1:05:14 PM     LOG [InstanceLoader] AuthServiceModule dependencies initialized +21ms
[Nest] 18440  - 09/11/2025, 1:05:14 PM     LOG [NestMicroservice] Nest microservice successfully started +17ms
[Nest] 18440  - 09/11/2025, 1:05:14 PM     LOG [AuthService] 🚀 Product-Service TCP Microservice running on port 4504
[Nest] 18438  - 09/11/2025, 1:05:14 PM     LOG [NestMicroservice] Nest microservice successfully started +19ms
[Nest] 18438  - 09/11/2025, 1:05:14 PM     LOG [AuthService] 🚀 Tenant-Service TCP Microservice running on port 4502
[Nest] 18439  - 09/11/2025, 1:05:14 PM     LOG [NestMicroservice] Nest microservice successfully started +18ms
[Nest] 18439  - 09/11/2025, 1:05:14 PM     LOG [AuthService] 🚀 Auth-Service TCP Microservice running on port 4501
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [NestFactory] Starting Nest application...
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [InstanceLoader] ApiGatewayModule dependencies initialized +18ms
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [RoutesResolver] ApiGatewayController {/}: +7ms
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [RouterExplorer] Mapped {/, GET} route +4ms
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [NestApplication] Nest application successfully started +2ms
[Nest] 18441  - 09/11/2025, 1:05:14 PM     LOG [ApiGateway] 🚀 Api-Gateway is running on: http://localhost:3501

This way you can spin up all services with one command while keeping package.json clean.

Final Verification Checklist for Step 1

[x] Monorepo created (nestjs-tutorial)
[x] Apps generated (gateway, auth, tenant, user, product)
[x] Libs generated (common, database, email, redis, logger, auth)
[x] Dependencies installed (mongoose, redis, winston, microservices, config)
[x] Ports assigned (HTTP 3501, TCP 4501–4504)
[x] Logger contexts set for each service
[x] Custom welcome messages added
[x] Verified startup logs for all services

👉 Now you have a working monorepo with 5 services + 6 shared libs all running independently.

README

Step2 Environment