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
});
Preload
If you are using iojs-v1.6.0 or later, 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.
$ node -r dotenv/config your_script.js
The configuration options below are supported as command line arguments in the format dotenv_config_<option>=value
$ node -r dotenv/config your_script.js dotenv_config_path=/custom/path/to/your/env/vars
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
Silent
Default: false
Dotenv outputs a warning to your console if missing a .env
file. Suppress
this warning using silent.
require('dotenv').config({silent: true});
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);
console.log(typeof config, config)
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: