DEV Community

Gabriel Dias Mazieri
Gabriel Dias Mazieri

Posted on

8 2 3 2 2

How to set up .env variables in a Nest.js project

As you problably should know, nest.js provides everything for you, it is a complete node.js framework and as expected also provides resources to set up environment variables for your api.

as always, the documentations is your friend, read more here: Configuration Nest.js docs

Here's how:

Nest.js provides a dependency exclusively for environment variables:

just install it:

npm i --save @nestjs/config

Now how to configure:

at your .env file you should have a PORT variable declared

PORT=3000
REDIS_PORT=6379
REDIS_HOST=localhost
Enter fullscreen mode Exit fullscreen mode

Create a config file as you prefer
src/config/config.ts:

export const config = () => ({
  port: process.env.PORT || 3000,
  redis_host: process.env.REDIS_HOST || 'localhost',
  redis_port: process.env.REDIS_PORT || 6379,
})
Enter fullscreen mode Exit fullscreen mode

at your app.module.ts:

import { config } from 'src/config/config';

@Module({
  imports: [
    ConfigModule.forRoot({
      isGlobal: true,
      load: [config],
    }),
})
Enter fullscreen mode Exit fullscreen mode

Here we are declaring our configuration as global, so all this will be applied to the whole Nest.js application, and all the configuration will be loaded from our config file, that should be imported as well.

Now, how to use our configuration?
Just instantiate your configuration at main.ts or anywhere you want or inject at any module you want to use.

Here's how to instantiate:

main.ts

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

async function bootstrap() {
  const configService = app.get(ConfigService);
  const port = configService.get('port'); // nest.js will handle the port variable from your .env file
}
Enter fullscreen mode Exit fullscreen mode

And,
How to inject at any module:

import { ConfigModule, ConfigService } from '@nestjs/config';

@Module({
  imports: [
    BullModule.forRootAsync({
      imports: [ConfigModule],
      useFactory: async (configService: ConfigService) => ({
        redis: {
          host: configService.get<string>('redis_host'),
          port: configService.get<number>('redis_port'),
        },
      }),
      inject: [ConfigService],
    }),
Enter fullscreen mode Exit fullscreen mode

Here I'm using Nest.js bull module because if your're configuring an environment variable at a custom module, you'll probably configuring some service for your application, mines using redis for queues service.

Sentry image

Hands-on debugging session: instrument, monitor, and fix

Join Lazar for a hands-on session where you’ll build it, break it, debug it, and fix it. You’ll set up Sentry, track errors, use Session Replay and Tracing, and leverage some good ol’ AI to find and fix issues fast.

RSVP here →

Top comments (1)

Collapse
 
natanb4 profile image
Natã Barbosa

Nice!

Billboard image

The Next Generation Developer Platform

Coherence is the first Platform-as-a-Service you can control. Unlike "black-box" platforms that are opinionated about the infra you can deploy, Coherence is powered by CNC, the open-source IaC framework, which offers limitless customization.

Learn more