Is it possible to have controllers named the following?
/admin
/admin/user
Sure. The first controller would be named Admin and the second one
Admin::User, actually a User controller class inside a module named
Admin.
However, just naming them correctly won’t do, the default routing
mechanism will interpret /admin/user as the action ‘user’ from the
controller ‘admin’. You can achieve what you want by tweaking your
routes, make sure to add something like this on the top of the
routes.rb file (it needs to be on top, so it matches at a higher
priority than the default route):