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/controllers/concerns/multi_tenancy.rb

@@ -0,0 +1,20 @@
+module MultiTenancy
+  extend ActiveSupport::Concern
+
+  included do
+    set_current_tenant_through_filter if respond_to? :set_current_tenant_through_filter
+    before_action :find_shop_by_subdomain_or_frist if respond_to? :before_action
+    helper_method :current_shop if respond_to? :helper_method
+  end
+
+  private
+  def find_shop_by_subdomain_or_frist
+    if request.subdomain.present?
+      shop_code = request.subdomain.partition('-').last
+      shop = Shop.find_by(shop_code: shop_code)
+    else
+      shop = Shop.first
+    end
+    set_current_tenant(shop)
+  end
+end