Whitelist in Rails:
Gemfile
gem 'rack-cors', :require => 'rack/cors'
config/application.rb
module Sample
class Application < Rails::Application
config.middleware.use Rack::Cors do
allow do
origins 'someserver.example.com'
resource %r{/users/\d+.json},
:headers => ['Origin', 'Accept', 'Content-Type'],
:methods => [:post, :get]
end
end
end
end