Extending Devise to use remote login

I'm trying to follow this blog post to allow remote authentication with devise, but I can't figure out a few things.

What do I call my new files, and where do I put them?

The first one, Devise::Models::RemoteAuthenticatable I assume I call remote_authenticatable.rb and put in a devise folder in my models folder?

The second file, "Warden strategy for Devise" I have no idea what to call it, or where to put it.

Any ideas? I found the tutorial pretty incomplete. It's linked to from the Devise instructions as the way to do this.

EDIT:

I've been doing more reading, and I'm not sure I need to do what it says in that blog post. I've been trying to simply PUT data to my Rails app, but can't get anything to work. Doing a PUT request causes devise to loose authentication.

回答1:

I know this question is years old, but I also found the tutorial to be incomplete, and I recently spent a couple days trying to get remote authentication to work. So I will provide my solution in case it helps someone in the future. I am using Ruby 2.2.2 and Rails 4.2.5.1.

First of all, this gist was an EXTREMELY helpful reference for me.

I also used the gem fakeweb to mock API calls.

Here are what my files look like:

app/models/user.rb

class User < include ActiveModel::Model
  # required because some before_validations are defined in devise
  include ActiveModel::Validations
  # required to define callbacks
  extend ActiveModel::Callbacks
  # taken from http://stackoverflow.com/questions/8936906/whats-the-correct-way-to-make-before-validation-etc-work-in-an-activemodel
  include ActiveModel::Validations::Callbacks
  extend Devise::Models

  # create getter and setter methods internally for the fields below
  attr_accessor :email, :auth_token

  #required by Devise
  define_model_callbacks :validation

  devise :remote_authenticatable, :timeoutable

  # Latest devise tries to initialize this class with values
  # ignore it for now
  def initialize(options={})
  end
end

lib/models/remote_authenticatable.rb

require 'fakeweb' #used for mocking API calls

module Devise
  module Models
    module RemoteAuthenticatable
      extend ActiveSupport::Concern

      #
      # Here you do the request to the external webservice
      #
      # If the authentication is successful you should return
      # a resource instance
      #
      # If the authentication fails you should return false
      #
      def remote_authentication(authentication_hash)

        FakeWeb.register_uri(:get, "http://localhost:3000/webservice/login.json",
                             :body => "{ \"success\": \"true\", \"auth_token\": \"secure_token_123\", \"email\": \"bob@1123.com\"}")

        # Your logic to authenticate with the external webservice
        response = Net::HTTP.get(URI.parse("http://localhost:3000/webservice/login.json"))

        self.email = JSON.parse(response)["email"]
        self.auth_token = JSON.parse(response)["auth_token"]
        return self
      end

      module ClassMethods
        ####################################
        # Overriden methods from Devise::Models::Authenticatable
        ####################################

        #
        # This method is called from:
        # Warden::SessionSerializer in devise
        #
        # It takes as many params as elements had the array
        # returned in serialize_into_session
        #
        # Recreates a resource from session data
        #
        def serialize_from_session(data, salt)
          resource = self.new
          resource.email = data['email']
          resource.auth_token = data['auth_token']
          resource
        end

        #
        # Here you have to return and array with the data of your resource
        # that you want to serialize into the session
        #
        # You might want to include some authentication data
        #
        def serialize_into_session(record)
          [
              {
                  :email => record.email,
                  :auth_token => record.auth_token
              },
              nil
          ]
        end

      end
    end
  end
end

config/initializers/remote_authenticatable.rb

module Devise
  module Strategies
    class RemoteAuthenticatable < Authenticatable
      #
      # For an example check : https://github.com/plataformatec/devise/blob/master/lib/devise/strategies/database_authenticatable.rb
      #
      # Method called by warden to authenticate a resource.
      #
      def authenticate!
        #
        # authentication_hash doesn't include the password
        #
        auth_params = authentication_hash
        auth_params[:password] = password

        #
        # mapping.to is a wrapper over the resource model
        #
        resource = mapping.to.new

        return fail! unless resource

        # remote_authentication method is defined in Devise::Models::RemoteAuthenticatable
        #
        # validate is a method defined in Devise::Strategies::Authenticatable. It takes
        #a block which must return a boolean value.
        #
        # If the block returns true the resource will be logged in
        # If the block returns false the authentication will fail!
        #
        # resource = resource.remote_authentication(auth_params)
        if validate(resource){ resource = resource.remote_authentication(auth_params) }
          success!(resource)
        end
      end
    end
  end
end

config/initializers/devise.rb

Devise.setup do |config|
  # ...
  # ...
  # OTHER CONFIGURATION CODE HERE
  # ...
  # ...

  # ==> Warden configuration
  # If you want to use other strategies, that are not supported by Devise, or
  # change the failure app, you can configure them inside the config.warden block.
  #
  # config.warden do |manager|
  #   manager.intercept_401 = false
  #   manager.default_strategies(scope: :user).unshift :some_external_strategy
  # end

  # BEGIN code that was added to this file
  config.warden do |manager|
    manager.strategies.add(:remote_authenticatable, Devise::Strategies::RemoteAuthenticatable)
    manager.default_strategies(:scope => :user).unshift :remote_authenticatable
  end

  Devise.add_module :remote_authenticatable, :controller => :sessions, :route => { :session => :routes }
  # END code that was added to this file

  # ...
  # ...
  # OTHER CONFIGURATION CODE HERE
  # ...
  # ...
end

config/application.rb

# ...
# ...
# OTHER CODE HERE
# ...
# ...

module RemoteAuth
  class Application < Rails::Application
    # ...
    # OTHER CODE HERE
    # ...

    # BEGIN code that was added to this file
    config.autoload_paths += Dir["#{config.root}/lib/**/"]
    config.autoload_paths += Dir["#{config.root}/app/models/**/"]
    # END code that was added to this file
  end
end

回答2:

This Gist shows you exactly how to do this. There are a few extra steps, like activating the :token_authenticatable module in your user model, and in config/devise.rb