How to enable registration - ruby-on-rails

Question

I have a website that works without problems. Here is the routes file:
Testpager::Application.routes.draw do
devise_for :users
resources :news, only: [:index, :show]
resources :documents, only: [:index, :show]
namespace :admin do
resources :documents, only: [:index, :show, :destroy, :edit, :update, :new, :create]
resources :news, only: [:index, :show, :destroy, :edit, :update, :new, :create]
get "admin" => 'documents#index'
end
get "contacts/index"
get "services/index"
get "index/index"
get "admin/index"
root 'index#index'
end
I would like to add a registration system. To do this I'm using Devise.
My actions are:
I installed the Devise gem.
Ran rails g devise:install
Added this to application.html.erb:
<p class="notice"><%= notice %></p>
<p class="alert"><%= alert %></p>
Ran rails g devisw User
Ran rake db:migrate
Ran rails server
I opened the URL http://localhost:3000/users/sign_up
I got the following error message:
ActionController::UrlGenerationError in Devise::Registrations#new
Showing /home/kalinin/rails/testpager/app/views/shared/_nav_main.html.erb where line #6 raised:
No route matches {:action=>"index", :controller=>"devise/index"}
Extracted source (around line #6):
<ul>
<li>
<%= link_to 'index', controller: "index", action: "index" %>
</li>
Trace of template inclusion: app/views/layouts/application.html.erb
Here is the controller:
class IndexController < ApplicationController
def index
end
end
The view for IndexController exists.

Answer 1

Check out this link About Adding Custom fields to a Devise registration: http://jacopretorius.net/2014/03/adding-custom-fields-to-your-devise-user-model-in-rails-4.html. What you will need to do is set up a Registrations Controller that inherits from Devise::RegistrationsController. This quick tutorial is easy to read and understand.