如何将Devise的Rails应用程序转换为OAuth提供程序？

I have a Rails application with admin accounts using Devise for authentication. I am creating a second application and would like to authenticate using the first application instead of duplicating admin accounts in the second application. So my idea is to turn the first application into an OAuth provider so that the second app can simply act as an OAuth client using something like OmniAuth. Have you done this before? Is there a plugin which adds the ability to Devise to be able to act as an OAuth provider? What do I need to change/add in order to turn the app into an OAuth provider?I have a Rails application with admin accounts