SwiftDotenv

A one-stop shop for working with environment values in a Swift program.

Overview

SwiftDotenv is a small and compact Swift scripting library that allows you to load and save .env files at runtime and query for those values as well as system provided environemntal values via ProcessInfo. It's a single abstraction for dealing with environment variables at runtime in a local configuration file that doesn't get committed to version control, rather than hardcoding strings into your app or framework.

IMPORTANT: Please note that storing secrets or other sensitive information in the .env file does not necessarily make your app secure. For more information, see this great article from NSHipster.

What is a .env file?

.env files are used, most often in server-side applications, to inject environment variables into an application during active development. They can contain api keys, secrets, and other sensitive information and therefore should not be committed to version control. An environment file should only exist locally on a development machine; on a continuous integration system like TravisCI or CircleCI, environment variables are added via the respective UI in lieu of a .env file.

When should I use this library?

SwiftDotenv is primarily meant for scripting use-cases only, not within applications. This is because in order to access the .env file from your application, it would have to be included and bundled with your application which defeats the purpose of keeping them separate to start with. You can however still use Dotenv as a Swiftier way of interacting with the system environment variables which will just proxy to processInfo.environment.

Installation

SwiftDotenv supports Swift Package Manager and can be added by adding this entry to your Package.swift manifest file:

.package(url: "https://github.com/thebarndog/swift-dotenv.git", .upToNextMajor("2.0.0"))

You can also use solutions such as swift-sh for a less cumbersome scripting setup.

Usage

import SwiftDotenv

// load in environment variables
try Dotenv.configure()

// access values
print(Dotenv.apiSecret)

Dotenv

To configure the environment with values from your environment file, call Dotenv.configure(atPath:overwrite:):

try Dotenv.configure()

It can optionally be provided with a path:

try Dotenv.configure(atPath: ".custom-env")

and the ability to not overwrite currently existing environment variables:

try Dotenv.configure(overwrite: false)

To read values:

let key = Dotenv.apiKey // using dynamic member lookup
let key = Dotenv["API_KEY"] // using regular subscripting

To set new values:

Dotenv.apiKey = .string("some-secret")
Dotenv["API_KEY"] = .string("some-secret")

// set a value and turn off overwriting 
Dotenv.set(value: "false", forKey: "DEBUG_MODE", overwrite: false)

The Dotenv structure can also be given a custom delimeter, file manager, and process info:

Dotenv.delimeter = "-" // default is "="
Dotenv.processInfo = ProcessInfo() // default is `ProcessInfo.processInfo`
Dotenv.fileManager = FileManager() // default is `FileManager.default`

Contributing

If you find a bug, have an idea for a feature request, or want to help out, please open an issue describing your problem or a pull request with your feature. Please follow the Code of Conduct at all times.

Made with Swift and ❤️.