Paypal IPN on Rails app not being called

Question

We are using Paypal Adaptive Chained payments to allow contributions on a crowd funding website. I've got everything working as far as making the payment and being returned to the 'return_url' after a successful payment (in the sandbox).

Paypals documentation on testing IPN in the Sandbox is sparse. Perhaps I missed a setting somewhere to enable IPN callbacks?

I would like to be able to use the IPN callback to verify a successful payment. I would like to see the callback JSON so I know which field to capture and compare with. I have found sample code, but the IPN callback doesn't seem to be called in the Sandbox. I've tried to output the params like so (also the puts statement isn't called):

****backers_controller.rb
class BackersController < ApplicationController    
include ActiveMerchant::Billing::Integrations

  def callback_ipn
    puts "callback: ipn"
    notify = PaypalAdaptivePayment::Notification.new(request.raw_post)
    puts notify.to_yaml
  end

  def callback_return
    puts "callback: return"
    @backer = Backer.find(params[:id])
    @reward = @project.rewards.find_by_id(@backer.reward_id)
    @backer.callback

    respond_to do |format|
      format.html { render :layout => 'application_proj_back_blog' }
      format.json { render json: @backer }
    end
  end

(The 'callback_return' action is working)

****backer.rb
class Backer < ActiveRecord::Base
  include ActionDispatch::Routing::UrlFor
  include Rails.application.routes.url_helpers

def purchase
  project = Project.find(self.project_id)
  default_url_options[:host] = 'localhost:3000'
  proj_owner_email = User.find(project.user_id).email
  recipients = [{:email => PRIMARY_EMAIL,
               :amount => total_pledge,
               :primary => true},
              {:email => project.paypal_email,
               :amount => project_owner_cut,
               :primary => false}
  ]
  response = GATEWAY.setup_purchase(
    :action_type => "PAY_PRIMARY",
    :return_url => callback_return_project_backer_url(project, self),
    :cancel_url => callback_cancel_project_backer_url(project, self),
    :ipn_notification_url => callback_ipn_project_backer_url(project, self),
    :currency_code =>"USD",
    :receiver_list => recipients
  )
  puts response.to_yaml
  pay_key = response["payKey"]

  pledge_transactions.create!(:action => "purchase", :amount => total_pledge, :response => response)
  return response["payKey"]
end

Back in backers_controller.rb, 'def purchase' calls the purchase:

****backers_controller.rb
class BackersController < ApplicationController

  def purchase
    @backer = Backer.find(params[:id])
    @backer.purchase

    redirect_to (GATEWAY.redirect_url_for(@backer.purchase))
  end

Answer 1

It turns out my authentication was preventing paypal from calling my ipn listener.