ArRollout is the ActiveRecord version of (Rollout)[], written after the wonderful Railscast (315-rollout-and-degrade)[] by Ryan Bates (thank you). Originally released as but now maintained at

This project rocks and uses MIT-LICENSE.


To use this gem, add on your gemfile

gem 'ar_rollout'

and run the generator:

rails generate ar_rollout

This will create for you the initializer and the migration.

The migration looks like this:

class CreateRollout < ActiveRecord::Migration
  def up
    create_table :rollouts do |t|
      t.string :name
      t.string :group
      t.integer :user_id
      t.integer :percentage
      t.integer :failure_count

  def down
    drop_table :rollouts

The initializer like this:

ArRollout.configure do |configure|
  # # Here you can define the logic for your own groups
  # # For example, if you have a admin? method for your User class
  # # you can define an :admin group:

  configure.define_group(:all) do |user|

  # configure.define_group :admin do |user|
  #   user.admin?
  # end

  # What if you want to add your 3 developers using email to a :dev group?
  # configure.define_group :devs do |user|
  #   ["[email protected]", "[email protected]"].include?
  # end

You have to run the migration to have the table rollouts created in database:

rake db:migrate

And that's it. You're now ready to use ArRollout.

If you want to add a feature to a group you define in config/initializer/ar_rollout.rb, in your rails console you can do:

ArRollout.activate_group  :my_new_amazing_feature, :tester
ArRollout.activate_user   :my_new_amazing_feature, current_user

Or via rake with:

rake rollout:activate_group[my_new_amazing_feature,all]

So, in your controller/view you can use the helper method rollout? :my_new_amazing_feature, which will test if the current_user is enabled to that feature.

In your *_controller.rb:

before_filter :rollout
around_filter :degrade


def rollout
  redirect_to root_url, alert: "Feature unavailable" unless rollout? :phone

def degrade
  degrade_feature(:phone) { yield }

List known features with:


Versions and ToDo


  • Optimize user lookup
  • Optimize database structure
  • Merge ArRollout and Rollout class methods
  • Autodetection of new features from code, before rollout begins

Version 0.0.20 - 04 Dec 2012

  • Add Group, Membership, OptOut

Version 0.0.17 - 29 Nov 2012

  • ArRollout caches groups

Version 0.0.16 - 29 Nov 2012

  • Add rake task 'rollout:summary'

Version 0.0.14 - 28 Nov 2012

  • Add rake task 'rollout:list'

Version 0.0.7 - 16 Aug 2012

  • Add

Version 0.0.4 - 16 Aug 2012

  • Add percentage support
  • Add feature list with ArRollout.features

Version 0.0.3 - 16 Aug 2012

  • Add ArRollout.deactivate_all method and rake task

Version 0.0.2 - 16 Aug 2012

  • Add :all to default initializer

Version 0.0.1 - 13 Jan 2012

  • Generator which create both migration and initializer
  • activate_group and deactivate_group methods are available
  • activate_user_ and deactivate_user methods are available