Using RailsAdmin without devise

rails_admin_without_devise.rb

# add RailsAdmin to the Gemfile
# do NOT add devise
gem "rails_admin", :git => "git://github.com/sferik/rails_admin.git"

# run Bundler
bundle

# run the generator for RailsAdmin
# looks like it's broken, but it just does not install devise
# you may also remove the app/config/locales/devise.en.yml
rails generate rails_admin:install_admin

# create an initializer for using CanCan with RailsAdmin
# found here: http://everydayrails.com/2010/12/17/rails-admin-panel.html
# config/initializers/rails_admin.rb
require "rails_admin/application_controller"

module RailsAdmin
  class ApplicationController < ::ApplicationController
    before_filter :can_admin?
    
    private
    
    def can_admin?
      raise CanCan::AccessDenied if current_user.nil? || !current_user.admin?
    end
  end
end

# RailsAdmin needs two additional things to get it working with my OmniAuth setup
# 1. an email attribute on the User class, which i simply redirected to the nickname
# app/models/user.rb
def email
  nickname
end

# 2. a logout route that matches Devises name schema
# config/routes.rb
match '/auth/destroy_user_session', :to => 'sessions#destroy_user_session', :as => :destroy_user_session

# this simply redirects to the original logout
# app/controllers/sessions_controller.rb
def destroy_user_session
  redirect_to destroy_session_path
end

This doesn't seem to work. When the HTTP Basic authentication box appears, pressing cancel without providing any credentials grants access to rails_admin. I fixed it by doing the following:

In config/initializers/rails_admin.rb:

RailsAdmin.config do |config|
  config.authorize_with do
    authenticate_or_request_with_http_basic('Site Message') do |username, password|
      username == 'foo' && password == 'bar'
    end
  end

  # rest of configuration

end

Thanks for the tip, updated it :)

This did not work for me. Here is my code:

RailsAdmin.config do |config|
  config.authorize_with do
    authenticate_or_request_with_http_basic('Site Message') do |username, password|
      username == ENV["ADMIN_KEY"] && password == ENV["ADMIN_PASSWORD"]
    end
  end  
  config.actions do
    dashboard                     # mandatory
    index                         # mandatory
    new
    export
    bulk_delete
    show
    edit
    delete
    show_in_app
  end
  config.main_app_name { ['grade-system', 'Admin'] }
end

but how to logout with this authentication?

This works well locally but doesn't seem to work with Heroku.
It doesn't break, but the /admin page bypasses the authorization window completely when accessed after being deployed to Heroku.
I may be deploying wrong.. Any tips?

How to add a normal authentication (not basic authentication) for rails admin. I have created a dedicated model Admin, apart from user table. Any tips?