如何在rails下设置webrick的访问控制允许值?

I have written a small rails app to serve up content to another site via xmlhttprequests that will be operating from another domain (it will not be possible to get them running on the same server). I understand I will need to set access-control-allow-origin on my rails server to allow the requesting web page to access this material.I have written a small rails app to serve up co