Nest config
You can find the source code of this tutorial at: https://github.com/ynwd/nest-init/tree/config
Install nest-config
$ npm i --save @nestjs/config
Import config service (src/app.module.ts)
import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { UserModule } from './modules/user/user.module';
import { AuthModule } from './modules/auth/auth.module';
import { ConfigModule } from '@nestjs/config';
@Module({
imports: [ConfigModule.forRoot({ isGlobal: true }), UserModule, AuthModule],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}
The @nestjs/config package internally uses dotenv.
The above code will load and parse a .env file from the default location (the project root directory), merge key/value pairs from the .env file with environment variables assigned to process.env, and store the result in a private structure that you can access through the ConfigService.
Next, inject config service on database provider (src/database/database.providers.ts)
import { ConfigService } from '@nestjs/config';
import { DATA_SOURCE } from 'src/common/constants';
import { DataSource } from 'typeorm';
export const databaseProviders = [
{
provide: DATA_SOURCE,
useFactory: async (configService: ConfigService) => {
const dataSource = new DataSource({
type: 'postgres',
host: configService.get('DB_HOST'),
port: configService.get<number>('DB_PORT'),
username: configService.get('DB_USERNAME'),
password: configService.get('DB_PASSWORD'),
database: configService.get('DB_NAME'),
synchronize: configService.get<boolean>('DB_SYNC'),
entities: [__dirname + '/../**/*.entity{.ts,.js}'],
});
return dataSource.initialize();
},
inject: [ConfigService],
},
];
This is the .env file that define app environment
DB_NAME=test
DB_USERNAME=postgres
DB_PASSWORD=root
DB_PORT=5432
DB_HOST=localhost
DB_SYNC=true