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.
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 });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 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 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`.
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
.envfile into ENV when the environment is bootstrapped."
npm install dotenv --save
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
});
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 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.
Default: false
Dotenv outputs a warning to your console if missing a .env file. Suppress
this warning using silent.
require('dotenv').config({silent: true});
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'});
Default: utf8
You may specify the encoding of your file containing environment variables using this option.
require('dotenv').config({encoding: 'base64'});
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' }
The parsing engine currently supports the following rules:
BASIC=basic becomes {BASIC: 'basic'}# are treated as commentsEMPTY= becomes {EMPTY: ''})SINGLE_QUOTE='quoted' becomes {SINGLE_QUOTE: "quoted"})MULTILINE="new\nline" becomes{MULTILINE: 'new
line'}
JSON={"foo": "bar"} becomes {JSON:"{\"foo\": \"bar\"}")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 basicprocess.env.TEST would equal exampleprocess.env.DNE would equal ""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.
Here's just a few of many repositories using dotenv:
[1.2.0] - 2015-06-20
package.jsonFAQs
Loads environment variables from .env file
The npm package dotenv receives a total of 40,449,474 weekly downloads. As such, dotenv popularity was classified as popular.
We found that dotenv demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 4 open source maintainers collaborating on the project.
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