Rackup

Rackup is a command-line tool for running Rack-based Ruby web applications. It uses a configuration file (typically config.ru) to define how the application should be built and served, often launching a web server like WEBrick, Puma, or Unicorn. It simplifies the process of starting Rack-compatible applications by handling server setup and middleware configuration.

Also known as: rackup, rack up, rackup command, config.ru runner, Rack server launcher

Why learn Rackup?

Developers should use Rackup when working with Ruby web frameworks like Ruby on Rails or Sinatra that are built on Rack, as it provides a standardized way to deploy and test applications locally or in production. It's particularly useful for configuring middleware stacks, specifying server options, and ensuring consistent application bootstrapping across different environments.

Learning Resources

• docs: Rack Documentation - Rackup
• tutorial: RubyGuides - Introduction to Rack and Rackup
• docs: Sinatra Book - Using Rackup
• video: YouTube - Rack and Rackup Explained