ConfigModule setup in NestJS - Mini Project: Build & Apply

ConfigModule setup

📖 Scenario: You are building a NestJS application that needs to manage configuration settings safely and efficiently.

🎯 Goal: Set up the ConfigModule in a NestJS app to load environment variables and make them available throughout the app.

📋 What You'll Learn

Create a configuration file with environment variables

Import ConfigModule in the root module

Configure ConfigModule to load environment variables globally

Use ConfigService to access configuration values

💡 Why This Matters

🌍 Real World

Managing environment variables is essential for configuring apps differently in development, testing, and production without changing code.

💼 Career

Understanding ConfigModule setup is important for backend developers working with NestJS to build scalable and maintainable applications.

1

Create a .env file with environment variables

Create a file named .env in the project root with these exact entries:
DATABASE_HOST=localhost
DATABASE_PORT=5432
API_KEY=12345

NestJS

# Create a .env file with the specified environment variables

Need a hint?

The .env file contains key-value pairs for configuration.

2

Import ConfigModule in AppModule

In app.module.ts, import ConfigModule from @nestjs/config and add ConfigModule.forRoot() to the imports array of @Module.

NestJS

import { Module } from '@nestjs/common';
// Your code here

Need a hint?

Use ConfigModule.forRoot() to load environment variables automatically.

3

Configure ConfigModule to be global

Modify the ConfigModule.forRoot() call in app.module.ts to include { isGlobal: true } so the configuration is available throughout the app.

NestJS

import { Module } from '@nestjs/common';
import { ConfigModule } from '@nestjs/config';

@Module({
  imports: [
    // Add isGlobal option here
  ],
})
export class AppModule {}

Need a hint?

Setting isGlobal: true makes ConfigModule available everywhere without importing again.

4

Use ConfigService to access environment variables

In any service, inject ConfigService from @nestjs/config in the constructor and use this.configService.get('DATABASE_HOST') to access the DATABASE_HOST value.

NestJS

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

@Injectable()
export class DatabaseService {
  constructor(private configService: ConfigService) {
    // Your code here
  }
}

Need a hint?

Inject ConfigService in the constructor and call get() with the environment variable name.