Configure for ngrok

config/environments/development.rb

@@ -1,5 +1,6 @@
 Rails.application.configure do
     # Settings specified here will take precedence over those in config/application.rb.
+    config.hosts << "grid-api.ngrok.io"
 
     # In the development environment your application's code is reloaded on
     # every request. This slows down response time but is perfect for development

config/initializers/cors.rb

@@ -7,7 +7,7 @@
 
 Rails.application.config.middleware.insert_before 0, Rack::Cors do
   allow do
-    origins '127.0.0.1:1234'
+    origins ['127.0.0.1:1234', 'grid.ngrok.io', 'grid-api.ngrok.io']
 
     resource '*',
       headers: :any,