Environment configuration files in Ruby on Rails - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of environment configuration files in Rails?

They store settings that change depending on where the app runs, like development, test, or production. This helps the app behave correctly in each place.

beginner

Name the three default Rails environment configuration files.

development.rb, test.rb, and production.rb inside the config/environments directory.

intermediate

How does Rails decide which environment configuration file to use?

Rails uses the RAILS_ENV environment variable to pick the right config file. If not set, it defaults to development.

intermediate

Why should sensitive data not be stored directly in environment configuration files?

Because these files can be shared or pushed to public code repositories. Instead, use environment variables or encrypted credentials.

intermediate

What is the role of config/application.rb compared to environment config files?

config/application.rb holds settings common to all environments, while environment files hold settings specific to each environment.

Which file would you edit to change settings only for the production environment in Rails?

A config/environments/development.rb

B config/environments/production.rb

C config/application.rb

D config/database.yml

The production.rb file holds settings specific to the production environment.

What does Rails use to determine the current environment?

A config/environment.rb file

B config/routes.rb

C Gemfile

D RAILS_ENV environment variable

Rails checks the RAILS_ENV variable to know which environment to run.

Where should you put settings that apply to all environments in a Rails app?

A config/application.rb

B config/environments/test.rb

C config/environments/production.rb

D config/secrets.yml

config/application.rb holds shared settings for all environments.

Why avoid putting passwords directly in environment config files?

A Passwords must be in the database only

B Rails does not support passwords in config files

C They might be exposed in version control

D It slows down the app

Storing passwords in config files risks exposing them if the code is shared.

If RAILS_ENV is not set, which environment does Rails use by default?

A development

B test

C production

D staging

Rails defaults to the development environment if RAILS_ENV is missing.

Explain how Rails uses environment configuration files to manage different settings for development, test, and production.

Think about how the app changes behavior depending on where it runs.

Describe best practices for handling sensitive information in Rails environment configurations.

Consider what happens if your code is shared publicly.