Add latest changes from gitlab-org/gitlab@13-9-stable-eev13.9.0-rc42

4 files changed, 181 insertions, 5 deletions

diff --git a/app/experiments/application_experiment.rb b/app/experiments/application_experiment.rb
index 7a8851d11ce..317514d088b 100644
--- a/app/experiments/application_experiment.rb
+++ b/app/experiments/application_experiment.rb
@@ -1,13 +1,20 @@
 # frozen_string_literal: true
 
-class ApplicationExperiment < Gitlab::Experiment
+class ApplicationExperiment < Gitlab::Experiment # rubocop:disable Gitlab/NamespacedClass
+  def enabled?
+    return false if Feature::Definition.get(feature_flag_name).nil? # there has to be a feature flag yaml file
+    return false unless Gitlab.dev_env_or_com? # we're in an environment that allows experiments
+
+    Feature.get(feature_flag_name).state != :off # rubocop:disable Gitlab/AvoidFeatureGet
+  end
+
   def publish(_result)
     track(:assignment) # track that we've assigned a variant for this context
     Gon.global.push({ experiment: { name => signature } }, true) # push to client
   end
 
   def track(action, **event_args)
-    return if excluded? # no events for opted out actors or excluded subjects
+    return unless should_track? # no events for opted out actors or excluded subjects
 
     Gitlab::Tracking.event(name, action.to_s, **event_args.merge(
       context: (event_args[:context] || []) << SnowplowTracker::SelfDescribingJson.new(
@@ -16,10 +23,39 @@ class ApplicationExperiment < Gitlab::Experiment
     ))
   end
 
+  def rollout_strategy
+    # no-op override in inherited class as desired
+  end
+
+  def variants
+    # override as desired in inherited class with all variants + control
+    # %i[variant1 variant2 control]
+    #
+    # this will make sure we supply variants as these go together - rollout_strategy of :round_robin must have variants
+    raise NotImplementedError, "Inheriting class must supply variants as an array if :round_robin strategy is used" if rollout_strategy == :round_robin
+  end
+
   private
 
+  def feature_flag_name
+    name.tr('/', '_')
+  end
+
   def resolve_variant_name
-    return variant_names.first if Feature.enabled?(name, self, type: :experiment)
+    case rollout_strategy
+    when :round_robin
+      round_robin_rollout
+    else
+      percentage_rollout
+    end
+  end
+
+  def round_robin_rollout
+    Strategy::RoundRobin.new(feature_flag_name, variants).execute
+  end
+
+  def percentage_rollout
+    return variant_names.first if Feature.enabled?(feature_flag_name, self, type: :experiment, default_enabled: :yaml)
 
     nil # Returning nil vs. :control is important for not caching and rollouts.
   end
@@ -41,7 +77,7 @@ class ApplicationExperiment < Gitlab::Experiment
   # default cache key strategy. So running `cache.fetch("foo:bar", "value")`
   # would create/update a hash with the key of "foo", with a field named
   # "bar" that has "value" assigned to it.
-  class Cache < ActiveSupport::Cache::Store
+  class Cache < ActiveSupport::Cache::Store # rubocop:disable Gitlab/NamespacedClass
     # Clears the entire cache for a given experiment. Be careful with this
     # since it would reset all resolved variants for the entire experiment.
     def clear(key:)
@@ -72,7 +108,6 @@ class ApplicationExperiment < Gitlab::Experiment
     end
 
     def write_entry(key, entry, **options)
-      return false unless Feature.enabled?(:caching_experiments)
       return false if entry.value.blank? # don't cache any empty values
 
       pool { |redis| redis.hset(*hkey(key), entry.value) }
diff --git a/app/experiments/members/invite_email_experiment.rb b/app/experiments/members/invite_email_experiment.rb
new file mode 100644
index 00000000000..4a03ebb7726
--- /dev/null
+++ b/app/experiments/members/invite_email_experiment.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module Members
+  class InviteEmailExperiment < ApplicationExperiment
+    exclude { context.actor.created_by.blank? }
+    exclude { context.actor.created_by.avatar_url.nil? }
+
+    INVITE_TYPE = 'initial_email'
+
+    def rollout_strategy
+      :round_robin
+    end
+
+    def variants
+      %i[avatar permission_info control]
+    end
+  end
+end
diff --git a/app/experiments/new_project_readme_experiment.rb b/app/experiments/new_project_readme_experiment.rb
new file mode 100644
index 00000000000..8f88ad2adc1
--- /dev/null
+++ b/app/experiments/new_project_readme_experiment.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class NewProjectReadmeExperiment < ApplicationExperiment # rubocop:disable Gitlab/NamespacedClass
+  include Gitlab::Git::WrapsGitalyErrors
+
+  INITIAL_WRITE_LIMIT = 3
+  EXPERIMENT_START_DATE = DateTime.parse('2021/1/20')
+  MAX_ACCOUNT_AGE = 7.days
+
+  exclude { context.value[:actor].nil? }
+  exclude { context.actor.created_at < MAX_ACCOUNT_AGE.ago }
+
+  def control_behavior
+    false # we don't want the checkbox to be checked
+  end
+
+  def candidate_behavior
+    true # check the checkbox by default
+  end
+
+  def track_initial_writes(project)
+    return unless should_track? # early return if we don't need to ask for commit counts
+    return unless project.created_at > EXPERIMENT_START_DATE # early return for older projects
+    return unless (commit_count = commit_count_for(project)) < INITIAL_WRITE_LIMIT
+
+    track(:write, property: project.created_at.to_s, value: commit_count)
+  end
+
+  private
+
+  def commit_count_for(project)
+    raw_repo = project.repository&.raw_repository
+    return INITIAL_WRITE_LIMIT unless raw_repo&.root_ref
+
+    begin
+      Gitlab::GitalyClient::CommitService.new(raw_repo).commit_count(raw_repo.root_ref, {
+        all: true, # include all branches
+        max_count: INITIAL_WRITE_LIMIT # limit as an optimization
+      })
+    rescue StandardError => e
+      Gitlab::ErrorTracking.track_exception(e, experiment: name)
+      INITIAL_WRITE_LIMIT
+    end
+  end
+end
diff --git a/app/experiments/strategy/round_robin.rb b/app/experiments/strategy/round_robin.rb
new file mode 100644
index 00000000000..7b80c0e984d
--- /dev/null
+++ b/app/experiments/strategy/round_robin.rb
@@ -0,0 +1,78 @@
+# frozen_string_literal: true
+
+module Strategy
+  class RoundRobin
+    CacheError = Class.new(StandardError)
+
+    COUNTER_EXPIRE_TIME = 86400 # one day
+
+    def initialize(key, variants)
+      @key = key
+      @variants = variants
+    end
+
+    def execute
+      increment_counter
+      resolve_variant_name
+    end
+
+    # When the counter would expire
+    #
+    # @api private Used internally by SRE and debugging purpose
+    # @return [Integer] Number in seconds until expiration or false if never
+    def counter_expires_in
+      Gitlab::Redis::SharedState.with do |redis|
+        redis.ttl(key)
+      end
+    end
+
+    # Return the actual counter value
+    #
+    # @return [Integer] value
+    def counter_value
+      Gitlab::Redis::SharedState.with do |redis|
+        (redis.get(key) || 0).to_i
+      end
+    end
+
+    # Reset the counter
+    #
+    # @private Used internally by SRE and debugging purpose
+    # @return [Boolean] whether reset was a success
+    def reset!
+      redis_cmd do |redis|
+        redis.del(key)
+      end
+    end
+
+    private
+
+    attr_reader :key, :variants
+
+    # Increase the counter
+    #
+    # @return [Boolean] whether operation was a success
+    def increment_counter
+      redis_cmd do |redis|
+        redis.incr(key)
+        redis.expire(key, COUNTER_EXPIRE_TIME)
+      end
+    end
+
+    def resolve_variant_name
+      remainder = counter_value % variants.size
+
+      variants[remainder]
+    end
+
+    def redis_cmd
+      Gitlab::Redis::SharedState.with { |redis| yield(redis) }
+
+      true
+    rescue CacheError => e
+      Gitlab::AppLogger.warn("GitLab: An unexpected error occurred in writing to Redis: #{e}")
+
+      false
+    end
+  end
+end