Minimal Rails 4.2 application

config.ru

# Using minimal rails application using rackup
# Rails 4.2.0
# ruby 2.1
#
# Start:
#   bundle exec RAILS_ENV=production rackup -p 3000 -s thin
#
# And open:
#
#   http://localhost:3000/hello/world
#

require "rails"
require "action_controller/railtie"

class MyApp < Rails::Application
  routes.append do
    get "/hello/world" => "hello#world"
  end

  config.cache_classes = true
  config.middleware.delete "Rack::Lock"
  config.middleware.delete "ActionDispatch::Flash"
  config.middleware.delete "Rack::ETag"
  config.middleware.delete "ActionDispatch::BestStandardsSupport"
  config.middleware.delete "ActionDispatch::ShowExceptions"
  config.middleware.delete "ActionDispatch::DebugExceptions"
  config.middleware.delete "ActiveSupport::Cache::Strategy::LocalCache::Middleware"
  config.middleware.delete "ActionDispatch::RemoteIp"
  config.middleware.delete "ActionDispatch::Cookies"
  config.middleware.delete "ActionDispatch::Callbacks"
  config.middleware.delete "ActionDispatch::Session::CookieStore"
  config.middleware.delete "Rack::Head"

  # config.secret_token = "49837489qkuweoiuoqwehisuakshdjksadhaisdy78o34y138974xyqp9rmye8yrpiokeuioqwzyoiuxftoyqiuxrhm3iou1hrzmjk"
end

class HelloController < ActionController::Metal
  include AbstractController::Rendering
  include ActionController::Rendering

  def world
    render :text => "Hello world!"
  end
end


MyApp.initialize!


puts ">> Starting Rails lightweight stack"
Rails.configuration.middleware.each do |middleware|
  puts "use #{middleware.inspect}"
end

puts "run #{Rails.application.class.name}.routes"

run MyApp

Gemfile

source 'https://rubygems.org'

gem 'thin'
gem 'rails', '4.2.0'
gem 'sqlite3'
gem 'sass-rails', '~> 5.0'
gem 'uglifier', '>= 1.3.0'
gem 'coffee-rails', '~> 4.1.0'
gem 'jquery-rails'
gem 'turbolinks'
gem 'jbuilder', '~> 2.0'
gem 'sdoc', '~> 0.4.0', group: :doc

group :development, :test do
  gem 'byebug'
  gem 'web-console', '~> 2.0'
  gem 'spring'
end