add health-check endpoint

config/application.rb

@@ -8,6 +8,7 @@ require 'action_controller/railtie'
 require 'action_view/railtie'
 require 'action_mailer/railtie'
 require 'active_job/railtie'
+require 'rails/health_controller'
 
 require_relative '../lib/api_path_consider_json_middleware'
 

config/routes.rb

@@ -6,6 +6,8 @@ Rails.application.routes.draw do
 
   root 'dashboard#index'
 
+  get 'up' => 'rails/health#show'
+
   devise_for :users,
              path: '/', only: %i[sessions passwords omniauth_callbacks],
              controllers: begin