Find yourself missing a rails console analogue in your other Ruby web applications? This lightweight gem provides a Rack::Console class that will load your Rack application's code and environment into an IRB or Pry session. Either use Rack::Console.new.start directly, or run the provided rack-console executable.

Add this line to your application's Gemfile:

gem 'rack-console'

And then execute:

$ bundle install

Or install it system-wide:

$ gem install rack-console

Rack::Console ships with a rack-console executable that will load your application in an IRB shell (or Pry if that's included in your Gemfile). Assuming you have a config.ru file in the current directory, simply run:

$ bundle exec rack-console
pry(main)>

Rack::Console supports some of the same things that rails console provides, as well as arguments used in rackup:

• An app method that will return your underlying Rack application with rack-test methods mixed in. You can perform fake requests to your app (e.g. response = app.get('/'))
• Supply the RACK_ENV as an argument (bundle exec rack-console production)
• A reload! method to discard new code or defined variables/constants
• The -c option (or --config) to specify a non-standard config.ru file
• The -r option (or --require) to require a file/library before Rack::Console loads
• The -I option (or --include) to specify paths (colon-separated) to add to $LOAD_PATH before Rack::Console loads

Because Rack::Console is just a class, it's easy to provide a console subcommand to a CLI for your own Rack framework. For example, here's how you could hypothetically implement a console subcommand for a generic Rack CLI using Thor:

require 'rack/console'
require 'thor'

module Rack
  class CLI < Thor
    desc 'console [ENVIRONMENT]', 'Start a Rack console'

    method_option :config,  aliases: '-c', type: 'string',
                            desc: 'Specify a Rackup file (default: config.ru)'
    method_option :require, aliases: '-r', type: 'string',
                            desc: 'Require a file/library before console boots'
    method_option :include, aliases: '-I', type: 'string',
                            desc: 'Add colon-separated paths to $LOAD_PATH'

    def console
      # Set a custom intro message:
      #   ENV['RACK_CONSOLE_INTRO'] = 'Loading Rack::Console...'
      #
      # Or, to prevent an intro message from being printed at all:
      #   ENV['IGNORE_RACK_CONSOLE_INTRO'] = 'true'
      Rack::Console.new(options).start
    end
  end
end

Rack::CLI.start(ARGV)

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request