DEV Community

Cover image for What is .env?
Rahul
Rahul

Posted on

What is .env?

In this tutorial, we will implement a .env into our NodeJS app to store environment variables inside of it.
Here I will introduce how you can use environment variables and for what you should use them. Let's Go.


dotenv

Dotenv is a zero-dependency module that loads environment variables from a .env file into process.env. Storing configuration in the environment separate from code is based on The Twelve-Factor App methodology.

init npm in our directory

npm init -y
Enter fullscreen mode Exit fullscreen mode

Install express (for the server) and dotenv

npm install express dotenv
Enter fullscreen mode Exit fullscreen mode

Install nodemon to start the server in watch mode.
Watch mode => Restarting the server on file change

npm install -D nodemon
Enter fullscreen mode Exit fullscreen mode

Create a file called ".env" in the root directory and insert a variable using NAME=VALUE.

We want to put in out PORT variable to define the port on which our server will start on that is PORT=3001.

In a real-world application, you want to store your API key and any kind of sensitive data like passwords here.

Importing Express

const express = require('express');

Initialize the app

const app = express();


Configure dotenv

This will load the variables we created in the .env file into the process.env so we can use it using process.env.VARIABLE_NAME

require('dotenv').congif();


Getting the port from the .env file and set 3000 as a fallback.

const port = process.env.PORT || 3000;

Starting the server using the port :

app.listen(port, () => console.log(server on :${ port }));


nodemon index.js

[nodemon] 2.0.4
[nodemon] to restart at any time, enter 'rs'
[nodemon] watching path(s): *.*
[nodemon] watching extensions: js,mjs,json
[nodemon] starting `node index.js`

Enter fullscreen mode Exit fullscreen mode

Now, this should be console logged. If we wouldn't run require('dotenv').config(); in the index.js then the log should be 'server on:3000' because then our fallback value would be applied for the port variable.

server on:3001


Originally here => https://rahulism.tech/article/what-is-env-file/


😀 SIMPLE



Top comments (0)