Dotenv component

The Dotenv component parses .env files to make environment variables stored in them accessible via std::env.

Installation

Add the dependency to your Cargo.toml:

[dependencies]
darkweb-dotenv = "^1.0"

Usage

Sensitive information and environment-dependent settings should be defined as environment variables (as recommended for twelve-factor applications). Using a .env file to store those environment variables eases development and CI management by keeping them in one "standard" place and agnostic of the technology stack you are using.

# .env
DB_USER=root
DB_PASS=pass

Load a .env file in your application via Dotenv::load():

use darkweb_dotenv::Dotenv;

let mut dotenv = Dotenv::new();
dotenv.load(".env").unwrap();

Access the values with std::env in your code:

let db_user = std::env::var("DB_USER").unwrap();

The load() method never overwrites existing environment variables. Use the overload() method if you need to overwrite them:

// ...
dotenv.overload(".env").unwrap();

As you're working with the Dotenv component you'll notice that you might want to have different files depending on the environment you're working in. Typically this happens for local development or Continuous Integration where you might want to have different files for your test and dev environments.

You can use Dotenv::load_env() to ease this process:

// ...
dotenv.load_env(".env", "APP_ENV", "dev").unwrap();

The Dotenv component will then look for the correct .env files to load. If the environment variable APP_ENV is defined, its value is used to load environment-specific files. If the variable is not defined, dev is assumed for APP_ENV.

The following files are loaded if they exist, the latter taking precedence over the former:

• .env --> committed environment defaults
• .env.local --> uncommitted file with local overrides
• .env.{APP_ENV} --> committed environment-specific defaults
• .env.{APP_ENV}.local --> uncommitted environment-specific local overrides

Links

• Documentation: https://docs.rs/darkweb-dotenv
• Repository: https://github.com/darkwebdesign/rust-dotenv
• Issue Tracker: https://github.com/darkwebdesign/rust-dotenv/issues

License

Dotenv is licensed under the MIT License - see the LICENSE file for details.