ENV in Node.Js

DotEnv has been an amazing library that I’ve used for years. Node.js v20.6.0 is finally release and include support .env files

We now have built-in support for the .env file. This mean that you can finally stop using the dotenv package to load environment variables from .env file. The authors of dotenv package is archived his Github repository.

Suppose you have a simple Express application

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import express from 'express';
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const app = express();
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app.get('/', async (req, res) => {
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  res.send(`Hello! My name is Nam Hoai Nguyen.`);
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});
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app.listen(PORT, async () => {
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  console.log(`App listening on port 3000`);
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});

Now, create a file that had been named .env at the root of the application next to app.js file to store the environment variables.

NAME="Nam Hoai Nguyen"
PORT=3000

By default, the Node.Js will be used file .env to store environment variables. We can change the file name for our application by using the argument env-file in start command. Example:

node --env-file=.env.local app.js

Need to change app.js to check .env is working correctly

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import express from 'express';
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const app = express();
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app.get('/', async (req, res) => {
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  res.send(`Hello! My name is Nam Hoai Nguyen.`);
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  res.send(`Hello! My name is ${process.env.NAME}.`);
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});
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app.listen(PORT, async () => {
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  console.log(`App listening on port 3000`);
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  console.log(`App listening on port ${process.env.PORT}`);
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});

Then now if you visit http://localhost:3000 you should see the text : “Hello, My name is Nam Hoai Nguyen”