How to Set Run Time Env Variable In Webpack?

To set a runtime environment variable in webpack, you can use the DefinePlugin plugin provided by webpack. This plugin allows you to create global constants which can be configured at compile time.

To use DefinePlugin, you need to add it to the plugins array in your webpack configuration file. You can then define the environment variables and their values that you want to use in your code.

For example, if you want to set a runtime environment variable called "API_URL" with the value "https://api.example.com", you can do so by adding the following configuration to your webpack.config.js file:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11

const webpack = require('webpack');

module.exports = {
  // Other webpack configuration settings
  
  plugins: [
    new webpack.DefinePlugin({
      'process.env.API_URL': JSON.stringify('https://api.example.com')
    })
  ]
};

Once you have added this configuration, you can access the environment variable in your code by using process.env.API_URL.

By setting runtime environment variables in webpack, you can configure your application to behave differently based on the environment it is running in, without having to hardcode any values in your code.

How to securely store environment variables in a Webpack project?

One common approach to securely store environment variables in a Webpack project is to use the dotenv-webpack package. This package allows you to load environment variables from a .env file and make them available to your webpack configuration.

Here are the steps to securely store environment variables in a Webpack project using the dotenv-webpack package:

1. Install the dotenv-webpack package by running the following command:

1

npm install dotenv-webpack --save-dev

1. Create a .env file in the root of your project and add your environment variables in the following format:

1
2

API_KEY=your_api_key
DATABASE_URL=your_database_url

1. In your webpack configuration file (e.g., webpack.config.js), require the dotenv-webpack package and pass it to the plugins array:

1
2
3
4
5
6
7
8

const Dotenv = require('dotenv-webpack');

module.exports = {
  // Webpack configuration
  plugins: [
    new Dotenv()
  ]
};

1. Now you can access your environment variables in your webpack configuration file using process.env:

1
2
3
4
5
6
7
8
9

module.exports = {
  // Webpack configuration
  entry: {
    main: process.env.ENTRY_FILE
  },
  output: {
    path: process.env.BUILD_PATH
  }
};

By following these steps, you can securely store your environment variables in a Webpack project and use them in your webpack configuration without exposing sensitive information.

What is the difference between global and local environment variables in Webpack?

Global environment variables in Webpack are set using the webpack.DefinePlugin plugin and are accessible globally throughout your application. These variables are determined at build time and can be used for defining constants or configuration values that are consistent across all parts of your application.

Local environment variables, on the other hand, are set using the webpack.EnvironmentPlugin plugin and are only accessible in the specific module in which they are defined. These variables can be used to provide configuration values that are specific to a particular module or feature within your application.

Overall, global environment variables are more commonly used for application-wide configuration, while local environment variables are used for module-specific configuration.

What is the best practice for managing environment variables in Webpack?

The best practice for managing environment variables in Webpack is to use the webpack DefinePlugin to define global constants that can be accessed in your code. This plugin allows you to pass variables to your code at build time, rather than hardcoding them directly in your source code.

To use the DefinePlugin, you can define your environment variables in your webpack configuration file, like so:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

// webpack.config.js
const webpack = require('webpack');

module.exports = {
  // other webpack configuration options
  plugins: [
    new webpack.DefinePlugin({
      'process.env.NODE_ENV': JSON.stringify(process.env.NODE_ENV),
      'process.env.API_URL': JSON.stringify(process.env.API_URL)
    })
  ]
};

Then in your code, you can access these variables like this:

1
2

// app.js
const apiUrl = process.env.API_URL;

By defining your environment variables in your webpack configuration file and using the DefinePlugin to pass them to your code, you can easily manage and customize your environment variables for different environments without having to modify your source code.

What is the difference between setting environment variables in development and production modes in Webpack?

In development mode, environment variables are typically defined in a separate .env file or through a command line interface like cross-env. This allows developers to easily switch between different configurations without having to modify the webpack configuration itself. These environment variables are usually not minified or obfuscated, making it easier to debug and test the application.

In production mode, environment variables are usually configured directly in the webpack configuration file. This allows for better optimization and performance, as the variables can be minified and compressed along with the rest of the code. Additionally, sensitive information such as API keys or passwords can be securely stored in the production environment variables to prevent exposure to the public.