CORS 错误 Rails 6 api 后端 + Angular 前端

Question

即使我在仅 Rails 6 api 的应用程序中安装并使用了rack-cors gem，我也会收到以下错误。

Access to XMLHttpRequest at 'api.backend.com' from origin 'frontend.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

我尝试添加 Angular 域作为起源，但没有成功。我还尝试将其添加到 application.rb 和 config.ru 中。注意到有用，但我很困惑。

Answer 1

尝试添加这个：

# config/initializers/cors.rb

Rails.application.config.middleware.insert_before 0, Rack::Cors do
  allow do
    origins 'frontend.com'
    resource '*', headers: :any, methods: [:get, :post, :patch, :put]
  end
end