Rails Controller for Chargify Webhooks

application.rb

# Add to the bottom of your application.rb file:
require 'digest/md5'

chargify_hooks_controller.rb

class Chargify::HooksController < ApplicationController
  protect_from_forgery :except => :handle
  skip_authorization_check # if using CanCan
  before_filter :verify, :only => :handle

  EVENTS = %w[ test signup_success signup_failure renewal_success renewal_failure payment_success
               payment_failure billing_date_change subscription_state_change
               subscription_product_change ].freeze

  def handle
    event = params[:event]

    unless EVENTS.include? event
      head :not_found and return
    end

    begin
      convert_payload
      self.send event
    rescue Exception => e
      Airbrake.notify(e)
      head :unprocessable_entity and return
    end
  end

  def test
    Rails.logger.debug 'Chargify Webhook test worked :)'
    head :ok
  end

  def signup_success
    head :ok
  end

  def signup_failure
    head :ok
  end

  def renewal_success
    head :ok
  end

  def renewal_failure
    head :ok
  end

  def payment_success
    head :ok
  end

  def payment_failure
    head :ok
  end

  def billing_date_change
    head :ok
  end

  def subscription_state_change
    head :ok
  end

  def subscription_product_change
    head :ok
  end

  protected
    def verify
      if params[:signature].blank?
        params[:signature] = request.headers["HTTP_X_CHARGIFY_WEBHOOK_SIGNATURE"]
      end

      unless Digest::MD5.hexdigest(CHARGIFY_CONFIG[:shared_key] + request.raw_post) == params[:signature]
        render :nothing, :status => :forbidden
      end
    end

    def convert_payload
      if params[:payload].has_key? :transaction
        @transaction = Chargify::Transaction.new params[:payload][:transaction]
      end

      if params[:payload].has_key? :subscription
        @subscription = Chargify::Subscription.new params[:payload][:subscription]
      end
    end
end

routes.rb

# Add to your routes.rb file:
match '/chargify/hooks', :to => 'chargify/hooks#handle', :via => :post, :as => 'chargify_hooks'