add oauth with google

config/application.rb

@@ -18,6 +18,10 @@ require "action_cable/engine"
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
+if ['development', 'test'].include? ENV['RAILS_ENV']
+  Dotenv::Railtie.load
+end
+
 module ProgressTest
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.

config/initializers/devise.rb

@@ -271,7 +271,12 @@ Devise.setup do |config|
   # ==> OmniAuth
   # Add a new OmniAuth provider. Check the wiki for more information on setting
   # up on your models and hooks.
-  # config.omniauth :github, 'APP_ID', 'APP_SECRET', scope: 'user,public_repo'
+  config.omniauth(
+    :google_oauth2,
+    ENV['GOOGLE_OAUTH_CLIENT_ID'],
+    ENV['GOOGLE_OAUTH_CLIENT_SECRET'],
+    {}
+  )
 
   # ==> Warden configuration
   # If you want to use other strategies, that are not supported by Devise, or

config/routes.rb

@@ -1,5 +1,5 @@
 Rails.application.routes.draw do
-  devise_for :users
+  devise_for :users, controllers: { omniauth_callbacks: 'users/omniauth_callbacks' }
   # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html
 
   # Defines the root path route ("/")