laserlemon/figaro

Figaro is a Ruby gem for Rails applications that handles sensitive configuration values like API keys, database passwords, and third-party service credentials. The core problem it solves is keeping those values out of your source code and away from Git, while still making them easy to use in the application and easy to deploy to a host like Heroku. The approach is straightforward: Figaro creates a single YAML file at config/application.yml and immediately adds it to .gitignore so it will never be committed. You put your keys and secrets in that file as simple key-value pairs. When the Rails app starts, Figaro reads the file and loads every value into ENV, the standard operating-system environment variable store. Your application code then reads from ENV the same way any twelve-factor app would, without knowing or caring that Figaro is involved. The same YAML file supports per-environment sections. If you need different values for development, test, and production, you add them under labeled sections. Test values only apply when running tests, production values only when the app is in production mode, and so on. You can also set a value to blank for a specific environment, which is useful for disabling analytics tracking or similar features during testing. Figaro includes a require_keys method for validating that certain values are present at startup. If a required key is missing, the app raises an error immediately rather than failing in some harder-to-diagnose way at runtime. This is especially useful for catching configuration mistakes before deploying. For Heroku deployments, Figaro includes a command that reads your production config from the YAML file and pushes all the values to Heroku's environment in one step, instead of setting each one by hand. For other hosts, the recommendation is to either manage a remote copy of the YAML file or set environment variables directly on the server. The README compares Figaro to dotenv, which solves the same problem with a slightly different convention. Both are valid, the main differences are file format (YAML vs KEY=VALUE pairs) and philosophy around committing development-only defaults.