Sinatra + Warden & Rails + Devise Example

config.ru

# /config.ru
# This file is used by Rack-based servers to start the application.
# File generated by "rails create MyApp"

# For Rails
require ::File.expand_path('../config/environment', __FILE__)

# For Sinatra
require './slim/slim.rb'
# - Make sinatra play nice
use Rack::MethodOverride
disable :run, :reload


# Mapping
# -------

# Rest with Rails
map "/" do
  run MyApp::Application
end

# Anything urls starting with /slim will go to Sinatra
map "/slim" do

  # make sure :key and :secret be in-sync with initializers/secret_store.rb initializers/secret_token.rb
  use Rack::Session::Cookie, :key => '<< see, initializers/secret_store.rb >>', :secret => '<< copy from initializers/secret_token.rb >>'

  # Point Warden to the Sinatra App
  use Warden::Manager do |manager|
    manager.failure_app = AppMain
    manager.default_scope = Devise.default_scope
  end
   
  # Borrowed from https://gist.github.com/217362
  Warden::Manager.before_failure do |env, opts|
    env['REQUEST_METHOD'] = "POST"
  end

  run AppMain
end

slim.rb

# /slim/slim.rb
APP_ROOT = File.expand_path(File.join(File.dirname(__FILE__), '..'))

require 'rubygems'
require 'sinatra'
require 'warden'
require 'json'

# =============
#    Const
# =============
RACK_ENV = "#{ENV['RACK_ENV']}".downcase

EMPTY_JSON = JSON.generate({})

class AppMain < Sinatra::Application
  set :root, APP_ROOT

  get '/' do
    redirect '/app.html'
  end

  get '/protected' do
    if env['warden'].unauthenticated?
      halt 401, "User is not logged in."
    end
    
    'Hello World'
  end

  # -------------
  #     Auth
  # -------------
  # See, from https://gist.github.com/217362
  post '/unauthenticated/?' do
    options = env['warden.options'] || {}
    code = options[:code] || 401
    message = options[:message] || 'Unauthorized'
      
    json = {
      :code => code,
        :message => message,
        :options => options
    }
    halt code, JSON.generate(json)
  end

  get '/logout/?' do
    env['warden'].logout
    redirect '/app.html'
  end

end

Along the way, you might have seen some of these errors. Hopefully, by listing them, Google will direct a few of you here and save you some hairs:

• no marshal_dump is defined for class Proc
• rack-1.0.1/lib/rack/session/cookie.rb:64:in 'dump'
• undefined method `unauthenticated?' for nil:NilClass
• if env['warden'].unauthenticated?
• file: whiny_nil.rb location: method_missing line: 48
• manager.default_scope = Devise.default_scope

Linkback: http://labnote.beedesk.com/sinatra-warden-rails-devise

One missing step was to update this file:
/config/initializers/session_store.rb

Patch:
diff --git a/config/initializers/session_store.rb b/config/initializers/session_store.rb
index 175240b..446d459 100755
--- a/config/initializers/session_store.rb
+++ b/config/initializers/session_store.rb
@@ -1,6 +1,6 @@

Be sure to restart your server when you modify this file.

-MyApp::Application.config.session_store :cookie_store, :key => '_MyApp_session'
+MyApp::Application.config.session_store :cookie_store, :key => '_common_session_id'