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

Gemfile.lock

@@ -46,6 +46,9 @@ GEM
       i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
+    acts_as_tenant (0.4.4)
+      rails (>= 4.0)
+      request_store (>= 1.0.5)
     aescrypt (1.0.0)
     airbrussh (1.4.0)
       sshkit (>= 1.6.1, != 1.7.0)
@@ -219,6 +222,8 @@ GEM
     rb-inotify (0.10.0)
       ffi (~> 1.0)
     redis (3.3.5)
+    request_store (1.4.1)
+      rack (>= 1.4)
     roo (1.13.2)
       nokogiri
       rubyzip
@@ -315,6 +320,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  acts_as_tenant
   aescrypt
   axlsx (= 2.0.1)
   axlsx_rails
@@ -374,10 +380,8 @@ DEPENDENCIES
   web-console (>= 3.3.0)
   whenever
 
-
 RUBY VERSION
    ruby 2.4.1p111
 
-
 BUNDLED WITH
    2.0.2