Rack::Cors Configuration Middleware

config.ru

require 'rack'
require './cors_wired'      

app = Rack::Builder.new  do
  use CorsWired.new
  run lambda { |env| [200, {'Content-Type' => 'text/plain'}, ['OK']] }  
end
run app

cors_wired.rb

require 'byebug'
require 'rack/cors'
require 'rack/builder'

# shrimp.rb
class CorsWired
  def initialize(app)
    @app = app
  end

  def call(env)
    use Rack::Cors do
      allow do
        origins '*'
        resource '*', :headers => :any, :methods => [:get, :post, :put, :options, :delete], :credentials => false
      end
    end
    @app.call(env)
  end
end

cors_wired_refactored.rb

require 'byebug'
require 'rack/cors'

# shrimp.rb
class CorsWired
  def initialize(app)
    @app = app
  end

  def call(env)
    cors = Rack::Cors.new(@app, {}) do
      allow do
        origins '*'
        resource '*', :headers => :any, :methods => [:get, :post, :put, :options, :delete], :credentials => false
      end
    end
    cors.call(env)
  end
end