dotenv-extended

I've been a big fan of the dotenv for a quite some time (in fact, this library uses dotenv under the hood for the .env file parsing). However, while working on some bigger projects, we realized that the managing of the .env files became a bit of a chore. As the files changed in the development environments, it became a tedious manual process to compare and figure out what needed to be added or removed in the other environments.

This library solves some of these issues by introducing the concept of 3 files which are used together to provide environment-specific variables, default values and a validation schema:

.env

The environment specific file (not committed to source control). This file will have sensitive information such as usernames, passwords, api keys, etc. These would be specific to each environment and should not be committed to source control. The format is a series of key-value pairs. Any line starting with # or ; are commented out and ignored.

# .env file
MONGO_HOST=localhost
MONGO_DATABASE=TestDB
MONGO_USER=dbusername
MONGO_PASS=dbpassword!

.env.defaults

Common configuration defaults across all environments (commited to source control). This contains overall app configuration values that would be common across environments. The .env.defaults file is loaded first and then the .env file is loaded and will overwrite any values from the .env.defaults file. Format is identical to the .env file.

.env.schema

Defines a schema of what variables should be defined in the combination of .env and .env.defaults. Optionally, you can have the library throw an error if all values are not configured or if there are extra values that shouldn't be there.

The .env.schema file should only have the name of the variable and the = without any value:

MONGO_HOST=
MONGO_DATABASE=
MONGO_USER=
MONGO_PASS=

Additionally .env.schema can include regular expressions; see below for how to configure the library to throw an error upon failed regex validation.

I have tried to stay as compatible as possible with the dotenv library but there are some differences.

Installation

npm i --save dotenv-extended

Usage

As early as possible in your main script:

require('dotenv-extended').load();

Or if you prefer import syntax:

import dotEnvExtended from 'dotenv-extended';
dotEnvExtended.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:

MONGO_HOST=localhost
MONGO_DATABASE=TestDB
MONGO_USER=dbusername
MONGO_PASS=dbpassword!

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

mongoose.connect('mongodb://' + process.env.MONGO_HOST + '/' + process.env.MONGO_DATABASE, {
    user: process.env.MONGO_USER,
    pass: process.env.MONGO_PASS
});

Load Configs from command line

You may also load the .env files from the command line. Add in the require dotenv-extended/config along with any of the options that the load method takes prefixed with dotenv_config_. e.g.:

node -r dotenv-extended/config your_script.js

Or to specify load options:

node -r dotenv-extended/config your_script.js dotenv_config_path=./env/.env dotenv_config_defaults=./env/.env.defaults

Load Environment Variables and pass to non-NodeJS script

New in 2.0.0, is a feature inspired by cross-env to allow you to load environment variables from your .env files and then pass them into a non-NodeJS script such as a shell script. This can simplify the process of maintaining variables used in both your Node app and other scripts. To use this command line executable, you will either need to install globally with the -g flag, or install dotenv-extended in your project and reference it from your npm scripts.

Install Globally:

npm install -g dotenv-extended

Now call your shell scripts through dotenv-extended (this uses the defaults):

dotenv-extended ./myshellscript.sh --whatever-flags-my-script-takes

Configure dotenv-extended by passing any of the dotenv-extended options before your command. Preceed each option with two dashes --:

dotenv-extended --path=/path/to/.env --defaults=/path/to/.env.defaults --errorOnMissing=true ./myshellscript.sh --whatever-flags-my-script-takes

The following are the flags you can pass to the dotenv-extended cli with their default values. these options detailed later in this document:

--encoding=utf8
--silent=true
--path=.env
--defaults=.env.defaults
--schema=.env.schema
--errorOnMissing=false     # or --error-on-missing=false
--errorOnExtra=false       # or --error-on-extra=false
--errorOnRegex=false       # or --error-on-regex=false
--includeProcessEnv=false  # or --include-process-env=false
--assignToProcessEnv=true  # or --assign-to-process-env=true
--overrideProcessEnv=false # or --override-process-env=true

Options

Defaults are shown below:

require('dotenv-extended').load({
	encoding: 'utf8',
	silent: true,
	path: '.env',
	defaults: '.env.defaults',
	schema: '.env.schema',
	errorOnMissing: false,
	errorOnExtra: false,
	errorOnRegex: false,
	includeProcessEnv: false,
	assignToProcessEnv: true,
	overrideProcessEnv: false
});

Configure via Environment Variables (New in 2.8.0)

You may also set the configuration values via environment variables loaded from process.env shown below with defaults:

DOTENV_CONFIG_ENCODING=utf8
DOTENV_CONFIG_SILENT=true
DOTENV_CONFIG_PATH=.env
DOTENV_CONFIG_DEFAULTS=.env.defaults
DOTENV_CONFIG_SCHEMA=.env.schema
DOTENV_CONFIG_ERROR_ON_MISSING=false
DOTENV_CONFIG_ERROR_ON_EXTRA=false
DOTENV_CONFIG_ERROR_ON_REGEX=false
DOTENV_CONFIG_INCLUDE_PROCESS_ENV=false
DOTENV_CONFIG_ASSIGN_TO_PROCESS_ENV=true
DOTENV_CONFIG_OVERRIDE_PROCESS_ENV=false

The load() function always returns an object containing the variables loaded from the .env and .env.defaults files. By default the returned object does not contain the properties held in process.env but rather only the ones that are loaded from the .env and .env.defaults files.

const myConfig = require('dotenv-extended').load();

encoding (default: utf8)

Sets the encoding of the .env files

silent (default: true)

Sets whether a log message is shown when missing the .env or .env.defaults files.

path (default: .env)

The main .env file that contains your variables.

defaults (default: .env.defaults)

The file that default values are loaded from.

schema (default: .env.schema)

The file that contains the schema of what values should be available from combining .env and .env.defaults

errorOnMissing (default: false)

Causes the library to throw a MISSING CONFIG VALUES error listing all of the variables missing the combined .env and .env.defaults files.

errorOnExtra (default: false)

Causes the library to throw a EXTRA CONFIG VALUES error listing all of the extra variables from the combined .env and .env.defaults files.

errorOnRegex (default: false)

Causes the library to throw a REGEX MISMATCH error listing all of the invalid variables from the combined .env and .env.defaults files. Also a SyntaxError is thrown in case .env.schema contains a syntactically invalid regex.

includeProcessEnv (default: false)

Causes the library add process.env variables to error checking. The variables in process.env overrides the variables in .env and .env.defaults while checking

assignToProcessEnv (default: true)

Sets whether the loaded values are assigned to the process.env object. If this is set, you must capture the return value of the call to .load() or you will not be able to use your variables.

overrideProcessEnv (default: false)

By defaut, dotenv-entended will not overwrite any varibles that are already set in the process.env object. If you would like to enable overwriting any already existing values, set this value to true.

Examples

Consider the following three files:

# .env file
DB_HOST=localhost
DB_USER=databaseuser-local
DB_PASS=databasepw!
SHARE_URL=http://www.example.com

# .env.defaults
DB_USER=databaseuser
DB_DATABASE=MyAppDB

# .env.schema
DB_HOST=[a-z]+
DB_USER=[a-z]+
DB_PASS=
DB_DATABASE=
API_KEY=

Load files with default options

const myConfig = require('dotenv-extended').load();

myConfig.DB_HOST === process.env.DB_HOST === "localhost"
myConfig.DB_USER === process.env.DB_USER === "databaseuser-local"
myConfig.DB_PASS === process.env.DB_PASS === "localhost"
myConfig.DB_DATABASE === process.env.DB_DATABASE === "MyAppDB"
myConfig.SHARE_URL === process.env.SHARE_URL === "http://www.example.com"

Load files with errorOnMissing

const myConfig = require('dotenv-extended').load({
    errorOnMissing: true
});

// Throws ERROR `MISSING CONFIG VALUES: API_KEY`

Load files with errorOnExtra

const myConfig = require('dotenv-extended').load({
    errorOnExtra: true
});

// Throws ERROR `EXTRA CONFIG VALUES: SHARE_URL`

Load files with errorOnRegex

const myConfig = require('dotenv-extended').load({
    errorOnRegex: true
});

// Throws ERROR `REGEX MISMATCH: DB_USER`

Contributing

See CONTRIBUTING.md

Change Log

See CHANGELOG.md

License

See LICENSE