Class: Gitlab::Experiment::Rollout::Feature

Inherits:
Percent
  • Object
show all
Defined in:
lib/gitlab/experiment/rollout/feature.rb

Instance Method Summary collapse

Instance Method Details

#enabled? ⇒ Boolean

For this rollout strategy to consider an experiment as enabled, we must:

  • have a feature flag yaml file that declares it.

  • be in an environment that permits it.

  • not have rolled out the feature flag at all (no percent of actors, no inclusions, etc.)

Returns:

  • (Boolean) 


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# File 'lib/gitlab/experiment/rollout/feature.rb', line 14

def enabled?
  return false unless feature_flag_defined?
  return false unless Gitlab.com?
  return false unless ::Feature.enabled?(:gitlab_experiment, type: :ops)

  feature_flag_instance.state != :off
end

#execute_assignment ⇒ Object

For assignment we first check to see if our feature flag is enabled for “self”. This is done by calling ‘#flipper_id` (used behind the scenes by `Feature`). By default this is our `experiment.id` (or more specifically, the context key, which is an anonymous SHA generated using the details of an experiment.

If the ‘Feature.enabled?` check is false, we return nil implicitly, which will assign the control. Otherwise we call super, which will assign a variant evenly, or based on our provided distribution rules.



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# File 'lib/gitlab/experiment/rollout/feature.rb', line 31

def execute_assignment
  super if ::Feature.enabled?(feature_flag_name, self, type: :experiment)
end

#flipper_id ⇒ Object

This is what’s provided to the ‘Feature.enabled?` call that will be used to determine experiment inclusion. An experiment may provide an override for this method to make the experiment work on user, group, or projects.

For example, when running an experiment on a project, you could make the experiment assignable by project (using chatops) by implementing a ‘flipper_id` method in the experiment:

def flipper_id

context.project.flipper_id

end

Or even cleaner, simply delegate it:

delegate :flipper_id, to: -> { context.project }



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# File 'lib/gitlab/experiment/rollout/feature.rb', line 51

def flipper_id
  return experiment.flipper_id if experiment.respond_to?(:flipper_id)

  "Experiment;#{id}"
end