How to manage environment variables on NestJS

#nestjs #dotenv #backend #api

Environment variables allow us to manage the configuration of our applications separate from our codebase. Separating configurations make it easier for our application to be deployed in different environments(development,test,production).Also,large applications tend to have many environment variables.

If you are working on some project with nestjs and want to configure your app secrets and credentials in a more efficient way, you came to the right place.In this article, I would like to share initial configuration and some tip to use environment variables with Nestjs.

Description

A common application level tool is nestjs-easyconfig which allows us to load environment variables from a file named .env[producton|dev|test].
Nestjs-easyconfig loads configs from your .env (Wraps dotenv module) ⚙️ 🔥

Installation

$ npm install nestjs-easyconfig
$ yarn add nestjs-easyconfig

Usage

With config file supplied (basic):

import  { Module }  from  '@nestjs/common';
import { EasyconfigModule } from  'nestjs-easyconfig';

@Module({
 imports:  [EasyconfigModule.register({path: './config/.env'})],
})
export  class  AppModule  {}

With config file supplied and safe set to true:

import  { Module }  from  '@nestjs/common';
import { EasyconfigModule } from  'nestjs-easyconfig';

@Module({
 imports:  [EasyconfigModule.register({path: './config/.env', safe: true})],
})
export  class  AppModule  {}

By default safe is set to false. When safe is set to true, the module compares the supplied env
file with the sample env file to find missing keys. If any keys which are in .env.sample but not in the evironment used, it is immediately reported in console.

Note: To use this, a sample env file .env.sample should be placed in the root dir

Without config file supplied:

import  { Module }  from  '@nestjs/common';
import { EasyconfigModule } from  'nestjs-easyconfig';

@Module({
 imports:  [EasyconfigModule.register({})],
})
export  class  AppModule  {}

In this case, you have to pass in the NODE_ENV value and the .env file to read will be determined accordingly.
Loads environment variables from .env.[development|test|production][.local] files
For example, NODE_ENV=dev will make the app read .env.dev