Single database for multiple shops

Use ActsAsTenant as Multi-tenancy for shops

See below files:
- app/controllers/concern/multi_tenancy.rb
- app/models/application_record.rb
- app/models/shop.rb

An initializer can be created to control option in ActsAsTenant.
config/initializers/acts_as_tenant.rb
require 'acts_as_tenant/sidekiq'
ActsAsTenant.configure do |config|
  config.require_tenant = false # true
end

more details: https://github.com/ErwinM/acts_as_tenant

app/models/printer/order_queue_printer.rb

@@ -38,7 +38,7 @@ class Printer::OrderQueuePrinter < Printer::PrinterWorker
       end
     # end
 
-    shop = Shop.first
+    shop = Shop.current_shop
     directory_name = 'public/orders_'+shop.shop_code
     Dir.mkdir(directory_name) unless File.exists?(directory_name)
 
@@ -80,7 +80,7 @@ class Printer::OrderQueuePrinter < Printer::PrinterWorker
     print_setting = PrintSetting.all.order("id ASC")
     order=print_query('order_summary', order_id)
 
-    shop = Shop.first
+    shop = Shop.current_shop
     directory_name = 'public/orders_'+shop.shop_code
     Dir.mkdir(directory_name) unless File.exists?(directory_name)
 
@@ -192,7 +192,7 @@ class Printer::OrderQueuePrinter < Printer::PrinterWorker
 
     order=print_query('booking_summary', booking_id)
 
-    shop = Shop.first
+    shop = Shop.current_shop
     directory_name = 'public/orders_'+shop.shop_code
     Dir.mkdir(directory_name) unless File.exists?(directory_name)