purge cache pubsub implementation

app.rb

@@ -545,6 +545,9 @@ post '/change_name' do
     redirect '/settings'
   end
 
+  old_host = current_site.host
+  old_file_paths = current_site.file_list.collect {|f| f.filename}
+
   current_site.username = params[:name]
 
   if current_site.valid?
@@ -553,6 +556,10 @@ post '/change_name' do
       current_site.move_files_from old_username
     }
 
+    old_file_paths.each do |file_path|
+      PurgeCacheWorker.async_queue "#{old_host}/#{file_path}"
+    end
+
     flash[:success] = "Site/user name has been changed. You will need to use this name to login, <b>don't forget it</b>."
     redirect '/settings'
   else

environment.rb

@@ -50,6 +50,14 @@ Sidekiq.configure_client do |config|
   config.redis = sidekiq_redis_config
 end
 
+if $config['pubsub_url']
+  $pubsub = Redis.new url: $config['pubsub_url'] 
+end
+
+if $config['pubsub_url'].nil? && ENV['RACK_ENV'] == 'production'
+  raise 'pubsub_url is missing from config'
+end
+
 require File.join(DIR_ROOT, 'workers', 'thumbnail_worker.rb')
 require File.join(DIR_ROOT, 'workers', 'screenshot_worker.rb')
 require File.join(DIR_ROOT, 'workers', 'email_worker.rb')

models/site.rb

@@ -184,6 +184,7 @@ class Site < Sequel::Model
 
     %w{index not_found}.each do |name|
       File.write file_path("#{name}.html"), render_template("#{name}.erb")
+      PurgeCacheWorker.perform_async "#{host}/#{name}.html"
       ScreenshotWorker.perform_async values[:username], "#{name}.html"
     end
 
@@ -205,6 +206,10 @@ class Site < Sequel::Model
       self.updated_at = Time.now
       save(validate: false)
     }
+
+    site_files.file_list.collect {|f| f.filename}.each do |f|
+      PurgeCacheWorker.async_queue "#{host}/#{f}"
+    end
   end
 
 =begin
@@ -279,6 +284,8 @@ class Site < Sequel::Model
     FileUtils.mv uploaded.path, file_path(filename)
     File.chmod(0640, file_path(filename))
 
+    PurgeCacheWorker.perform_async "#{host}/#{filename}"
+
     ext = File.extname(filename).gsub(/^./, '')
 
     if ext.match HTML_REGEX
@@ -324,6 +331,8 @@ class Site < Sequel::Model
     rescue Errno::ENOENT
     end
 
+    PurgeCacheWorker.perform_async "#{host}/#{filename}"
+
     ext = File.extname(filename).gsub(/^./, '')
 
     screenshots_delete(filename) if ext.match HTML_REGEX
@@ -340,6 +349,7 @@ class Site < Sequel::Model
 
   def install_new_html_file(name)
     File.write file_path(name), render_template('index.erb')
+    PurgeCacheWorker.perform_async "#{host}/#{name}"
   end
 
   def file_exists?(filename)

workers/purge_cache_worker.rb

@@ -0,0 +1,14 @@
+class PurgeCacheWorker
+  include Sidekiq::Worker
+  sidekiq_options queue: :purgecache, retry: 10, backtrace: true
+
+  def perform(url)
+    begin
+      $pubsub.publish 'purge', url
+    rescue Redis::BaseConnectionError => error
+      puts "Pubsub error: #{error}, retrying in 1s"
+      sleep 1
+      retry
+    end
+  end
+end