SNS in Rails

example_notification.json

{
     "Type" : "SubscriptionConfirmation",
     "MessageId" : "0941b7b3-4797-44e5-8079-dbf8ef09793f",
     "Token" : "2336412f37fb687f5d51e6e241d164b0533302ec696efc8f113cd2252ce8a925c1e44a3c4ca2984675da85b9bd8c05da85337beb1f24a9c659b22ed3a8cc682f3457c4ead28d392a40e5c35c0e9>
     "TopicArn" : "arn:aws:sns:us-west-2:164053224164:email-list",
     "Message" : "You have chosen to subscribe to the topic arn:aws:sns:us-west-2:164053224164:email-list.\nTo confirm the subscription, visit the SubscribeURL included in this message",
     "SubscribeURL" : "https://sns.us-west-2.amazonaws.com/?Action=ConfirmSubscription&TopicArn=arn:aws:sns:us-west-2:164053224164:email-list&Token=REDACTED",
     "Timestamp" : "2013-10-05T17:00:04.135Z",
     "SignatureVersion" : "1",
     "Signature" : "<REDACTED>"
     "SigningCertURL" : "https://sns.us-west-2.amazonaws.com/SimpleNotificationService-e372f8ca30337fdb084e8ac449342c77.pem"
 }

notification.rb

#  id                :integer          not null, primary key
#  raw               :text
#  created_at        :datetime         not null
#  updated_at        :datetime         not null
#  type              :string(255)
#  message_id        :string(255)
#  topic_arn         :string(255)
#  message           :text
#  subscribe_url     :text
#  subscribed        :boolean
#  notification_type :string(255)
#

require 'uri'
require 'net/http'
 
# http://docs.aws.amazon.com/ses/latest/DeveloperGuide/notification-contents.html#complaint-object
# http://docs.aws.amazon.com/ses/latest/DeveloperGuide/notification-contents.html#bounce-object
# http://docs.aws.amazon.com/ses/latest/DeveloperGuide/notification-contents.html#mail-object
#
class Notification < ActiveRecord::Base
  self.inheritance_column = nil 

  scope :subscriptions, where(type: "SubscriptionConfirmation")
  scope :notifications, where(type: "Notification")

  attr_accessible :raw

  before_create :extract_data

  def data
    @data ||= JSON.parse(raw)
  end 

  def message_data
    @message_data ||= JSON.parse(message)
  end

  def extract_data
    self.type          ||= data["Type"]
    self.message_id    ||= data["MessageId"]
    self.topic_arn     ||= data["TopicArn"]
    self.subscribe_url ||= data["SubscribeURL"]

    self.message       ||= data["Message"]

    self
  end

  # Types of notifications

  def confirmation?() type == "SubscriptionConfirmation" end
  def notification?() type == "Notification"             end

  # Confirms subscription.
  def confirm!
    uri = URI.parse(subscribe_url)
    res = ::Net::HTTP.start(uri.host, uri.port, :use_ssl => uri.scheme == 'https', :verify_mode => OpenSSL::SSL::VERIFY_NONE) do |https|
      https.request(Net::HTTP::Get.new(uri.request_uri))
    end 

    self.subscribed = res.is_a?(Net::HTTPOK)
  end
end

notifications_controller.rb

# routes.rb:
#
#   resources :notifications, only: [:create]
#
class NotificationsController < ApplicationController
  # POST /notifications
  # POST /notifications.json
  def create
    @notification = Notification.new(raw: request.raw_post)

    @notification.extract_data
    @notification.process!

    respond_to do |format|
      if @notification.save
        format.html { render text: "Notification received!", layout: false }
        format.json { render json: @notification, status: :created, location: @notification }
      else
        format.html { render text: "Cannot process notification", status: :unprocessable_entity, layout: false }
        format.json { render json: @notification.errors, status: :unprocessable_entity }
      end 
    end 
  end 
end