Dotenv-flow-webpack NPM

dotenv-flow-webpack

A Webpack plugin that allows you to securely use environment variables within your javascript web application, loading them using dotenv-flow's .env* files loading strategy.

dotenv-flow extends dotenv, adding support of NODE_ENV-specific .env* files like .env.development, .env.test, .env.stage, and .env.production, and the appropriate .env*.local overrides allowing your app to have multiple environments with selectively-adjusted environment variable setups and load them dynamically depending on the current NODE_ENV.

🌱 Inspired by dotenv-webpack, CreateReactApp's storing configs in .env* files approach, the Twelve-Factor App methodology in general, and its store config in the environment section in particular.

Key Features

Environment-based configuration: You can have different .env* files for various environments like development, test, and production.
Variable overriding (or environment-specific cascade): Allows you to selectively override the default and environment-specific variables with the appropriate .env*.local overrides.
Secure: Injects variables by replacing the process.env.<YOUR_VAR> entries with the actual values from your .env* files during the build process, thus exposing only those variables that are explicitly used in your code.
dotenv-flow as a Webpack plugin: directly integrates dotenv-flow with all its flexibility options to your build process making it easier to use environment variables without extra build scripts.

Installation

Using NPM:

$ npm install dotenv-flow-webpack --save-dev

Using Yarn:

$ yarn add dotenv-flow-webpack --dev

Basic usage

Here's how to include the dotenv-flow-webpack to your webpack.config.js:

// webpack.config.js

const DotenvFlow = require('dotenv-flow-webpack');

module.exports = {
  // ...other webpack configurations
  plugins: [
    new DotenvFlow({
      // configuration options
    })
  ],
  // ...other webpack plugins
};

Configuration options

`node_env`

Type: `string`

Default: `process.env.NODE_ENV || options.default_node_env`

By default, the plugin refers the NODE_ENV environment variable to detect the environment to use. With the node_env option you can force the module to use your custom environment value independent of process.env.NODE_ENV.

new DotenvFlow({
  node_env: 'production'
})

`default_node_env`

Type: `string`

Default: undefined

If the NODE_ENV environment variable is not set, the module doesn't load/parse any NODE_ENV-specific files at all. Therefore, you may want to use "development" as the default environment.

new DotenvFlow({
  default_node_env: 'development'
})

`path`

Type: `string`

Default: `process.cwd()` (current working directory)

With the path initialization option you can specify a path to .env* files directory.

new DotenvFlow({
  path: './config'
})

If the option is not provided, the current working directory is used.

`pattern`

Type: `string`

Default: `'.env[.node_env][.local]'`

Allows you to change the default .env* files' naming convention if you want to have a specific file naming structure for maintaining your environment variables' files.

Default Value

The default value ".env[.node_env][.local]" makes dotenv-flow-webpack look up and load the following files in order:

.env
.env.local
.env.${NODE_ENV}
.env.${NODE_ENV}.local

For example, when the proess.env.NODE_ENV (or options.node_env) is set to "development", dotenv-flow-webpack will be looking for and parsing (if found) the following files:

.env
.env.local
.env.development
.env.development.local

Custom Pattern

Here is a couple of examples of customizing the .env* files naming convention:

For example, if you set the pattern to ".env/[local/]env[.node_env]", dotenv-flow-webpack will look for these files instead:

.env/env
.env/local/env
.env/env.development
.env/local/env.development

… or if you set the pattern to ".env/[.node_env/].env[.node_env][.local]", the plugin will try to find and parse:

.env/.env
.env/.env.local
.env/development/.env.development
.env/development/.env.development.local

› Please refer to dotenv-flow.listFiles(options) to learn more.

`encoding`

Type: `string`

Default: `'utf8'`

You can specify the encoding of your files containing environment variables.

new DotenvFlow({
  encoding: 'base64'
})

`system_vars`

Type: `boolean`

Default: `false`

If true, all the predefined process.env.* variables will also be loaded. In accordance to the dotenv-flow's specification, all the predefined system environment variables will have higher priority over the .env* files defined.

new DotenvFlow({
  system_vars: true
})

`options.debug`

Type: `boolean`

Default: `false`

Enables detailed logging to debug why certain variables are not being set as you expect.

new DotenvFlow({
  debug: true
})

`silent`

Type: `boolean`

Default: `false`

Set to true to suppress all kinds of errors and warnings.

new DotenvFlow({
  silent: true
})

Project Example

Let's suppose you have the following files in your project:

# .env

DATABASE_HOST=127.0.0.1
DATABASE_PORT=27017
DATABASE_USER=default
DATABASE_PASS=
DATABASE_NAME=my_app

SERVICE_URL=/api/v1

# .env.development

DATABASE_NAME=my_app_dev

SERVICE_URL=http://localhost:3000/api/v1

# .env.test

SERVICE_URL=https://localhost:3001/api/v1

# .env.production

DATABASE_HOST=10.0.0.32
DATABASE_PORT=27017
DATABASE_USER=devops
DATABASE_PASS=1qa2ws3ed4rf5tg6yh
DATABASE_NAME=application_storage

SERVICE_URL=https://myapp.com/api/v1

// file1.js

if (process.env.NODE_ENV !== 'production') {
  console.log(`Running in the "${process.env.NODE_ENV}" mode.`);
}
else {
  console.log('We are in production!');
}

const USERS_ENDPOINT = process.env.SERVICE_URL + '/users';

console.log('USERS_ENDPOINT:', USERS_ENDPOINT);

Thus, when you build your app with NODE_ENV=development, the resulting bundle will include something like this:

// file1.js

if (true) {
  console.log("Running in the ".concat("development", " mode."));
} else {}

const USERS_ENDPOINT = "http://localhost:3000/api/v1" + '/users';

console.log('USERS_ENDPOINT:', USERS_ENDPOINT);

Or if you build your app with NODE_ENV=production, then the output will look like:

// file1.js

if (false) {} else {
  console.log('We are in production!');
}

const USERS_ENDPOINT = "https://myapp.com/api/v1" + '/users';

console.log('USERS_ENDPOINT:', USERS_ENDPOINT);

And after all the optimization procedures it will be compressed till:

console.log("We are in production!");
console.log("USERS_ENDPOINT:", "https://myapp.com/api/v1/users");

Make a note that values of DATABASE_(HOST/PORT/USER/PASSWORD/NAME) will not be present in the resulting bundle while they are not referenced anywhere in the code.