Gemfile
gem 'activeadmin', github: 'activeadmin'
gem 'devise'
gem 'inherited_resources', github: 'activeadmin/inherited_resources'
gem 'ransack', github: 'activerecord-hackery/ransack'
gem 'draper', '> 3.x'
bundle install
インストール
rails g active_admin:install
rails db:migrate
rails db:seed
※ 5からは、rakeじゃなくてrails
お試し
rails g model Article title:string sentence:string
rails g active_admin:resource Article