khuongduybui/dotenv-with-expand

Parse .env files with support for interpolation

DEPRECATION NOTICE

Support for .env file is now a builtin feature of Node.js. See https://nodejs.org/en/blog/release/v20.6.0#built-in-env-file-support

dotenv-with-expand

This is a drop-in replacement for dotenv but with preloaded dotenv-expand functionality.

Install

# with npm
npm install dotenv-with-expand

# or with Yarn
yarn add dotenv-with-expand

# or with pnpm
pnpm install dotenv-with-expand

Usage

As early as possible in your application, require and configure dotenv.

require('dotenv-with-expand').config();

Create a .env file in the root directory of your project. Add environment-specific variables on new lines in the form of NAME=VALUE. For example:

DB_HOST=localhost
DB_USER=root
DB_PASS=s1mpl3
DB_URI="${DB_USER}:${DB_PASS}@${DB_HOST}"

process.env now has the keys and values you defined in your .env file.

See dotenv-expand for more substitution examples.

const db = require('db');
db.connect({
  host: process.env.DB_HOST,
  username: process.env.DB_USER,
  password: process.env.DB_PASS,
});
console.log(`connected to ${process.env.DB_URI}`);

Preload

You can use the --require (-r) command line option to preload dotenv. By doing this, you do not need to require and load dotenv in your application code. This is the preferred approach when using import instead of require.

$ node -r dotenv-with-expand/config your_script.js

The configuration options below are supported as command line arguments in the format dotenv_config_<option>=value

$ node -r dotenv-with-expand/config your_script.js dotenv_config_path=/custom/path/to/your/env/vars

Additionally, you can use environment variables to set configuration options. Command line arguments will precede these.

$ DOTENV_CONFIG_<OPTION>=value node -r dotenv-with-expand/config your_script.js

$ DOTENV_CONFIG_ENCODING=latin1 node -r dotenv-with-expand/config your_script.js dotenv_config_path=/custom/path/to/.env

Config

config will read your .env file, parse the contents, assign it to process.env, and return an Object with a parsed key containing the loaded content or an error key if it failed.

Please refer to dotenv for more information.

Parse

The engine which parses the contents of your file containing environment variables is available to use. It accepts a String or Buffer and will return an Object with the parsed keys and values.

Please refer to dotenv for more information.

FAQ

Please refer to dotenv for more information.