The .env.example file is a template or example file used in software development, particularly within the context of Environment Variables management. This file serves several key purposes:
- Documentation: It provides a list of environment variables that are expected by an application, serving as documentation for developers who will set up or deploy the application.
- Security: By including an example rather than the actual values, sensitive information like API keys or database credentials are not exposed in version control systems like Git.
- Configuration Guidance: It guides developers on how to configure their environment for the application, showing which variables need to be set and often their expected format.
History and Evolution
The use of .env.example files has become more widespread with the rise of:
- Twelve-Factor App methodology, which advocates for strict separation of config from code.
- Docker and other containerization technologies, where environment variables are crucial for configuring applications at runtime.
Originally, configuration files were directly included in the codebase, which posed security risks when sensitive data was inadvertently committed. The .env.example file emerged as a best practice to avoid this issue while still providing clear guidance on application setup.
Usage and Best Practices
When using .env.example:
- Developers typically copy this file to a new file named .env, where actual values are entered.
- The .env.example should be included in version control, while the .env file should be added to .gitignore to prevent sensitive data exposure.
- It's good practice to include comments explaining the purpose of each variable or any special formats required.
Examples
Here's a typical example of what might be found in a .env.example file:
# Database Configuration
DB_HOST=localhost
DB_PORT=5432
DB_NAME=your_database
DB_USER=your_username
DB_PASSWORD=your_password
# API Keys
GOOGLE_API_KEY=
STRIPE_API_KEY=
# Application Settings
APP_ENV=development
APP_DEBUG=true
External Links
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