FEATURE: AWS SNS bounce notifications webhooks

Gemfile

@@ -65,6 +65,7 @@ gem 'fast_xor', platform: :mri
 gem 'fastimage'
 
 gem 'aws-sdk-s3', require: false
+gem 'aws-sdk-sns', require: false
 gem 'excon', require: false
 gem 'unf', require: false
 

Gemfile.lock

@@ -57,6 +57,9 @@ GEM
       aws-sdk-core (~> 3, >= 3.26.0)
       aws-sdk-kms (~> 1)
       aws-sigv4 (~> 1.0)
+    aws-sdk-sns (1.2.0)
+      aws-sdk-core (~> 3)
+      aws-sigv4 (~> 1.0)
     aws-sigv4 (1.0.3)
     barber (0.12.0)
       ember-source (>= 1.0, < 3.1)
@@ -452,6 +455,7 @@ DEPENDENCIES
   activesupport (= 5.2.2)
   annotate
   aws-sdk-s3
+  aws-sdk-sns
   barber
   better_errors
   binding_of_caller

app/controllers/webhooks_controller.rb

@@ -24,7 +24,7 @@ class WebhooksController < ActionController::Base
       end
     end
 
-    render body: nil, status: 200
+    success
   end
 
   def mailjet
@@ -41,7 +41,7 @@ class WebhooksController < ActionController::Base
       end
     end
 
-    render body: nil, status: 200
+    success
   end
 
   def mandrill
@@ -58,7 +58,7 @@ class WebhooksController < ActionController::Base
       end
     end
 
-    render body: nil, status: 200
+    success
   end
 
   def sparkpost
@@ -84,7 +84,21 @@ class WebhooksController < ActionController::Base
       end
     end
 
-    render body: nil, status: 200
+    success
+  end
+
+  def aws
+    raw  = request.raw_post
+    json = JSON.parse(raw)
+
+    case json["Type"]
+    when "SubscriptionConfirmation"
+      Jobs.enqueue(:confirm_sns_subscription, raw: raw, json: json)
+    when "Notification"
+      Jobs.enqueue(:process_sns_notification, raw: raw, json: json)
+    end
+
+    success
   end
 
   private
@@ -93,7 +107,7 @@ class WebhooksController < ActionController::Base
     render body: nil, status: 406
   end
 
-  def mailgun_success
+  def success
     render body: nil, status: 200
   end
 
@@ -129,7 +143,7 @@ class WebhooksController < ActionController::Base
       process_bounce(message_id, to_address, SiteSetting.hard_bounce_score)
     end
 
-    mailgun_success
+    success
   end
 
   def handle_mailgun_new(params)
@@ -149,7 +163,7 @@ class WebhooksController < ActionController::Base
       end
     end
 
-    mailgun_success
+    success
   end
 
   def process_bounce(message_id, to_address, bounce_score)

app/jobs/regular/confirm_sns_subscription.rb

@@ -0,0 +1,21 @@
+require "aws-sdk-sns"
+
+module Jobs
+
+  class ConfirmSnsSubscription < Jobs::Base
+    sidekiq_options retry: false
+
+    def execute(args)
+      return unless raw  = args[:raw].presence
+      return unless json = args[:json].presence
+
+      return unless subscribe_url = json["SubscribeURL"].presence
+      return unless Aws::SNS::MessageVerifier.new.authentic?(raw)
+
+      # confirm subscription by visiting the URL
+      open(subscribe_url)
+    end
+
+  end
+
+end

app/jobs/regular/process_sns_notification.rb

@@ -0,0 +1,36 @@
+require "aws-sdk-sns"
+
+module Jobs
+
+  class ProcessSnsNotification < Jobs::Base
+    sidekiq_options retry: false
+
+    def execute(args)
+      return unless raw  = args[:raw].presence
+      return unless json = args[:json].presence
+
+      return unless message = json["Message"].presence
+      return unless message["notificationType"] == "Bounce"
+      return unless message_id = message.dig("mail", "messageId").presence
+      return unless bounce_type = message.dig("bounce", "bounceType").presence
+
+      return unless Aws::SNS::MessageVerifier.new.authentic?(raw)
+
+      message.dig("bounce", "bouncedRecipients").each do |r|
+        if email_log = EmailLog.find_by(message_id: message_id, to_address: r["emailAddress"])
+          email_log.update_columns(bounced: true)
+
+          if email_log.user&.email.present?
+            if r["status"]&.start_with?["4."] || bounce_type == "Transient"
+              Email::Receiver.update_bounce_score(email_log.user.email, SiteSetting.soft_bounce_score)
+            else
+              Email::Receiver.update_bounce_score(email_log.user.email, SiteSetting.hard_bounce_score)
+            end
+          end
+        end
+      end
+    end
+
+  end
+
+end

config/routes.rb

@@ -15,10 +15,11 @@ Discourse::Application.routes.draw do
   match "/404", to: "exceptions#not_found", via: [:get, :post]
   get "/404-body" => "exceptions#not_found_body"
 
+  post "webhooks/aws" => "webhooks#aws"
   post "webhooks/mailgun"  => "webhooks#mailgun"
-  post "webhooks/sendgrid" => "webhooks#sendgrid"
   post "webhooks/mailjet"  => "webhooks#mailjet"
   post "webhooks/mandrill" => "webhooks#mandrill"
+  post "webhooks/sendgrid" => "webhooks#sendgrid"
   post "webhooks/sparkpost" => "webhooks#sparkpost"
 
   if Rails.env.development?