Adding embedded PuSH server

app/workers/pubsubhubbub/confirmation_worker.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class Pubsubhubbub::ConfirmationWorker
+  include Sidekiq::Worker
+  include RoutingHelper
+
+  def perform(subscription_id, mode, secret = nil, lease_seconds = nil)
+    subscription = Subscription.find(subscription_id)
+    challenge    = SecureRandom.hex
+
+    subscription.secret        = secret
+    subscription.lease_seconds = lease_seconds
+
+    response = HTTP.headers(user_agent: 'Mastodon/PubSubHubbub')
+                   .timeout(:per_operation, write: 20, connect: 20, read: 50)
+                   .get(subscription.callback_url, params: {
+                          'hub.topic' => account_url(subscription.account, format: :atom),
+                          'hub.mode'          => mode,
+                          'hub.challenge'     => challenge,
+                          'hub.lease_seconds' => subscription.lease_seconds,
+                        })
+
+    if mode == 'subscribe' && response.body.to_s == challenge
+      subscription.save!
+    elsif (mode == 'unsubscribe' && response.body.to_s == challenge) || !subscription.confirmed?
+      subscription.destroy!
+    end
+  end
+end