Devise & MongoMapper & Rails - Cannot see any devise pages (broken routes / actions) - ruby-on-rails-3

Question

I am getting "too many redirects" when I'm trying to access my /users/sign_up page
Devise + MongoMapper + Rails 3.2.13
rake routes:
users GET /users(.:format) users#index
POST /users(.:format) users#create
new_user GET /users/new(.:format) users#new
edit_user GET /users/:id/edit(.:format) users#edit
user GET /users/:id(.:format) users#show
PUT /users/:id(.:format) users#update
DELETE /users/:id(.:format) users#destroy
new_user_session GET /users/login(.:format) devise/sessions#new
user_session POST /users/login(.:format) devise/sessions#create
destroy_user_session DELETE /users/logout(.:format) devise/sessions#destroy
user_password POST /users/reset(.:format) devise/passwords#create
new_user_password GET /users/reset/new(.:format) devise/passwords#new
edit_user_password GET /users/reset/edit(.:format) devise/passwords#edit
PUT /users/reset(.:format) devise/passwords#update
cancel_user_registration GET /users/cancel(.:format) devise/registrations#cancel
user_registration POST /users(.:format) devise/registrations#create
new_user_registration GET /users/sign_up(.:format) devise/registrations#new
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
PUT /users(.:format) devise/registrations#update
DELETE /users(.:format) devise/registrations#destroy
root / customers#index
customers GET /customers(.:format) customers#index
POST /customers(.:format) customers#create
new_customer GET /customers/new(.:format) customers#new
edit_customer GET /customers/:id/edit(.:format) customers#edit
customer GET /customers/:id(.:format) customers#show
PUT /customers/:id(.:format) customers#update
DELETE /customers/:id(.:format) customers#destroy
Rails server console just spits this out over and over:
Started GET "/users/sign_in" for 127.0.0.1 at 2014-02-24 21:10:01 -0800
Processing by UsersController#show as HTML
Parameters: {"id"=>"sign_in"}
Completed 401 Unauthorized in 0ms
I read on their ReadMe that Devise is supposed to make some helper methods in my controller - I don't see any but the standard 7 from the generator.
It seems like it's trying to login as "sign_in" which I certainly didn't instruct it to do - this is a brand new Rails application basically just with one model - User - and one model - Customer - and absolutely no data or any other files yet. Literally just trying to get this Devise login page to render - or signup page - or any page.
Here is my entire routes.rb file right now:
resources :users
devise_for :users
root :to => "customers#index"
resources :customers
This happens when I have before_filter authenticate_user! in my Users Controller
So when I take that line out - and I just try to hit /users/sign_up - I get the following:
No route matches {:action=>"edit", :controller=>"users", :id=>nil}
It's supposed to redirect here:
edit_user_registration GET /users/edit(.:format) devise/registrations#edit
The controller action is :
def edit
#user = User.find(params[:id])
end
And of course - since there's nothing in my DB at all - #user is nil now - is that the issue?
How do people get Devise started??? I've never once successfully got this stupid thing to work.

Answer 1

You should have the line:
devise_for :users
above the line:
resources :users
That is because you need to set up the Devise resources for a model before anything else.
What you could also do is remap the Devise routes to you own. You'd replace resources :users with a devise_scope block. Here is the Documentation for it.