rails get app root/base url
问题 In my app I have a few APIs that under api domain. Now in one of the API I want to generate a url that pointing to the main domain, say test.com/blabla... I tried to use url_for but seems the default root_url or request.host is in api domain. Url_for will make it to be api.test.com/blabla.. while I want it to be test.com/blabla... Url_for can take a parameter host: ... to set it to be test.com/, the question is how can I get the root/base url (test.com) for host? root_url or request.host are