dotenv

What is dotenv?

The dotenv npm package is used to load environment variables from a .env file into process.env, providing a convenient way to configure your application's environment during development. It helps in managing sensitive credentials and configuration options by keeping them out of the codebase.

What are dotenv's main functionalities?

Basic Configuration

This is the simplest use case for dotenv. By calling `require('dotenv').config();`, dotenv reads the .env file, parses the contents, and loads them into `process.env`. After this, environment variables can be accessed using `process.env.VAR_NAME`.

require('dotenv').config();

Custom Path

If your .env file is not located in the root directory or you have multiple .env files, you can specify a custom path to your .env file using the `path` option.

require('dotenv').config({ path: '/custom/path/to/.env' });

Debugging

To assist in debugging, you can enable debug output by setting the `debug` option to `true`. This will log any errors to the console while reading the .env file.

require('dotenv').config({ debug: process.env.DEBUG });

Other packages similar to dotenv

dotenv-expand

dotenv-expand is an extension for dotenv. It allows you to have environment variables in your .env file that reference other environment variables, similar to variable expansion in Unix shell scripts. It's useful when you need to reduce redundancy in your .env files.

cross-env

cross-env allows you to set and use environment variables across platforms without worrying about platform-specific differences in how environment variables are set. Unlike dotenv, which is focused on loading variables from a file, cross-env is more about providing scripts with environment variables in a cross-platform way.

env-cmd

env-cmd is another npm package that allows you to specify a file containing environment variable definitions and then run a given command using those variables. It's similar to dotenv but is more focused on injecting environment variables into the command line for scripts, rather than loading them into `process.env`.

README

dotenv

Dotenv loads environment variables from .env into ENV (process.env).

"Storing configuration in the environment is one of the tenets of a twelve-factor app. Anything that is likely to change between deployment environments–such as resource handles for databases or credentials for external services–should be extracted from the code into environment variables.

But it is not always practical to set environment variables on development machines or continuous integration servers where multiple projects are run. Dotenv loads variables from a .env file into ENV when the environment is bootstrapped."

Brandon Keepers' Dotenv in Ruby

Install

npm install dotenv --save

Usage

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

require('dotenv').load();

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

That's it.

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

db.connect({
  host: process.env.DB_HOST,
  username: process.env.DB_USER,
  password: process.env.DB_PASS
});

Config

config will read your .env file, parse the contents, and assign it to process.env - just like load does. You can additionally, pass options to config.

Note: config and load are synonyms. You can pass options to either.

Options

Path

Default: .env

You can specify a custom path if your file containing environment variables is named or located differently.

require('dotenv').config({path: '/custom/path/to/your/env/vars'});

Encoding

Default: utf8

You may specify the encoding of your file containing environment variables using this option.

require('dotenv').config({encoding: 'base64'});

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.

var dotenv  = require('dotenv');
var buf    = new Buffer('BASIC=basic');
var config  = dotenv.parse(buf); // will return an object
console.log(typeof config, config) // object { BASIC : 'basic' }

Rules

The parsing engine currently supports the following rules:

• BASIC=basic becomes {BASIC: 'basic'}
• empty lines are skipped
• lines beginning with # are treated as comments
• empty values become empty strings (EMPTY= becomes {EMPTY: ''})
• single and double quoted values are escaped (SINGLE_QUOTE='quoted' becomes {SINGLE_QUOTE: "quoted"})
• new lines are expanded if in double quotes (MULTILINE='new\nline' becomes

{MULTILINE: 'new
line'}

• inner quotes are maintained (think JSON) (JSON={"foo": "bar"} becomes {JSON:"{\"foo\": \"bar\"}")

Expanding Variables

Basic variable expansion is supported.

BASIC=basic
TEST=$BASIC

Parsing that would result in {BASIC: 'basic', TEST: 'basic'}. You can escape variables by quoting or beginning with \ (e.g. TEST=\$BASIC). If the variable is not found in the file, process.env is checked. Missing variables result in an empty string.

BASIC=basic
TEST=$TEST
DNE=$DNE

TEST=example node -e 'require("dotenv").config();'

• process.env.BASIC would equal basic
• process.env.TEST would equal example
• process.env.DNE would equal ""

FAQ

Should I commit my .env file?

No. We strongly recommend against committing your .env file to version control. It should only include environment-specific values such as database passwords or API keys. Your production database should have a different password than your development database.

Contributing

See Contributing Guide

Who's using dotenv

Here's just a few of many repositories using dotenv:

• npm
• sendgrid-nodejs
• handshake.js
• google-oauth2-service-account
• kibble
• github-streaker

Changelog

[1.1.0] - 2015-03-31

Added

• Silent option to silence console.log when .env missing