Can't get rack-cors working in rails application

Question

I wanted to implement CORS in my rails application, so I googled rack-cors gem for it. And I did everything as was said in README, that is updated Gemfile accordingly and up

Answer 1

Here's how I fixed mine:

You just need to un-comment the Rack CORS gem in your Gemfile (if it's there) or just add it:

gem 'rack-cors'

And then run the code below to install the gem:

bundle install

Put the code below in config/application.rb of your Rails application. For example, this will allow GET, POST or OPTIONS requests from any origin on any resource:

module YourApp
  class Application < Rails::Application
    # ...

    # For Rails 5 Appications

    config.middleware.insert_before 0, Rack::Cors do
      allow do
        origins '*'
        resource '*', headers: :any, methods: [:get, :post, :options]
      end
    end

    # For Rails 3/4 Applications

    config.middleware.insert_before 0, "Rack::Cors" do
      allow do
        origins '*'
        resource '*', headers: :any, methods: [:get, :post, :options]
      end
    end
  end
end

Setting origins to '*' should be alright for development, but keep in mind that if you deploy to production you’ll want to change this value to match your front-end’s URI for security reasons.

Note: If you're running Rails, updating in config/application.rb should be enough. There is no need to update config.ru as well.

That's all

I hope this helps.