Load .env using Config Module in NestJS (NestJS Series 02)

load-env-using-config-module-in-nestjs.md

How to Load .env using Config Module in NestJS

1. Add @nestjs/config library to your dependencies in package.json

   $ yarn add @nestjs/config

2. Add src/modules/config/app.config.ts

    // src/modules/config/app.config.ts
   
   import { registerAs } from '@nestjs/config';
   
   export default registerAs('app', () => ({
     nodeEnv: process.env.NODE_ENV,
     name: process.env.APP_NAME,
     workingDirectory: process.env.PWD || process.cwd(),
     port: process.env.APP_PORT,
   }));

3. Add src/modules/config/database.config.ts

   // src/modules/config/database.config.ts
   
   import { registerAs } from '@nestjs/config';
   
   export default registerAs('database', () => ({
     url: process.env.DATABASE_URL,
   }));

4. Add src/modules/config/index.ts

   // src/modules/config/index.ts
   
   import appConfig from './app.config';
   import databaseConfig from './database.config';
   
   export const configLoads = [databaseConfig, appConfig];

5. Edit src/modules/app/app.module.ts

   // src/modules/app/app.module.ts
   
   import { Module } from '@nestjs/common';
   import { ConfigModule } from '@nestjs/config';
   import { configLoads } from '../config';
   
   const modules = [];
   
   export const global_modules = [
     ConfigModule.forRoot({
       load: configLoads,
       isGlobal: true,
       envFilePath: ['.env'],
     }),
   ];
   
   @Module({
     imports: [...global_modules, ...modules],
   })
   export class AppModule {}

6. Edit src/main.ts

   // src/main.ts
   
   import { NestFactory } from '@nestjs/core';
   import { AppModule } from './app.module';
   import { ConfigService } from '@nestjs/config';
   import { Logger } from '@nestjs/common';
   
   async function bootstrap() {
     const log = new Logger(bootstrap.name);
     // create application instance using NestFactory
     const app = await NestFactory.create(AppModule);
   
     // getting configService from application
     // to fetch port from app.config.ts config load
     const configService = app.get(ConfigService);
   
     const PORT = configService.get('app.port') || 8000;
   
     // used the port value here
     await app.listen(PORT);
   
     log.log(
       `NestJS Series (${process.env.npm_package_version}) start on port ${PORT}`,
     );
   }
   bootstrap();

7. Add .env

   NODE_ENV=development
   APP_PORT=8000
   APP_NAME="NestJS Series"
   
   # Database Configuration
   DATABASE_URL=postgresql://localhost:5432

8. Run the server in development mode

   $ yarn run start:dev