Document feature flag

app/controllers/projects/pipelines_controller.rb

@@ -176,7 +176,7 @@ class Projects::PipelinesController < Projects::ApplicationController
   end
 
   def retry
-    if Feature.enabled?(:background_pipeline_retry_endpoint, @project)
+    if Gitlab::Ci::Features.background_pipeline_retry_endpoint?(@project)
       ::Ci::RetryPipelineWorker.perform_async(pipeline.id, current_user.id) # rubocop:disable CodeReuse/Worker
     else
       pipeline.retry_failed(current_user)

config/feature_flags/development/background_pipeline_retry_endpoint.yml

+---
+name: background_pipeline_retry_endpoint
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/61270
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/330915
+milestone: '13.12'
+type: development
+group: group::pipeline authoring
+default_enabled: false

lib/gitlab/ci/features.rb

@@ -54,6 +54,10 @@ module Gitlab
       def self.gldropdown_tags_enabled?
         ::Feature.enabled?(:gldropdown_tags, default_enabled: :yaml)
       end
+
+      def self.background_pipeline_retry_endpoint?(project)
+        ::Feature.enabled?(:background_pipeline_retry_endpoint, project)
+      end
     end
   end
 end