Change how flipping features creates Geo events

To make sure a Geo event is created when a Feature Flag is flipped on
instance level, refactor the code how where the #log_geo_event call is
hooked in the Flipper code.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/247535

ee/changelogs/unreleased/tc-geo-ff.yml

+---
+title: Create a Geo cache invalidation event when toggling feature flags through the
+  API
+merge_request: 42070
+author:
+type: fixed

ee/lib/ee/feature.rb

@@ -2,70 +2,42 @@
 
 module EE
   module Feature
-    module ClassMethods
+    module ActiveSupportCacheStoreAdapter
       extend ::Gitlab::Utils::Override
 
-      override :enable
-      def enable(key, thing = true)
-        super
-        log_geo_event(key)
-      end
-
-      override :disable
-      def disable(key, thing = false)
-        super
-        log_geo_event(key)
-      end
-
-      override :enable_group
-      def enable_group(key, group)
-        super
-        log_geo_event(key)
-      end
-
-      override :disable_group
-      def disable_group(key, group)
-        super
-        log_geo_event(key)
+      override :remove
+      def remove(key)
+        super.tap do |result|
+          log_geo_event(key) if result
+        end
       end
 
-      override :enable_percentage_of_time
-      def enable_percentage_of_time(key, percentage)
-        super
-        log_geo_event(key)
+      override :clear
+      def clear(key)
+        super.tap do |result|
+          log_geo_event(key) if result
+        end
       end
 
-      override :disable_percentage_of_time
-      def disable_percentage_of_time(key)
-        super
-        log_geo_event(key)
-      end
-
-      override :enable_percentage_of_actors
-      def enable_percentage_of_actors(key, percentage)
-        super
-        log_geo_event(key)
+      override :enable
+      def enable(key, *_)
+        super.tap do |result|
+          log_geo_event(key) if result
+        end
       end
 
-      override :disable_percentage_of_actors
-      def disable_percentage_of_actors(key)
-        super
-        log_geo_event(key)
+      override :disable
+      def disable(key, *_)
+        super.tap do |result|
+          log_geo_event(key) if result
+        end
       end
 
       private
 
       def log_geo_event(key)
-        Geo::CacheInvalidationEventStore.new(cache_store.key_for(key)).create!
+        Geo::CacheInvalidationEventStore.new(key_for(key)).create!
       end
-
-      def cache_store
-        Flipper::Adapters::ActiveSupportCacheStore
-      end
-    end
-
-    def self.prepended(base)
-      base.singleton_class.prepend ClassMethods
     end
   end
 end

ee/spec/lib/ee/feature_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Feature do
+RSpec.describe Feature, stub_feature_flags: false do
   include EE::GeoHelpers
 
   describe '.enable' do

ee/spec/requests/api/features_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe API::Features, stub_feature_flags: false do
+  include EE::GeoHelpers
+
+  let_it_be(:admin) { create(:admin) }
+
+  before do
+    Feature.reset
+    Flipper.unregister_groups
+    Flipper.register(:perf_team) do |actor|
+      actor.respond_to?(:admin) && actor.admin?
+    end
+  end
+
+  describe 'POST /feature' do
+    let(:feature_name) { 'my_feature' }
+
+    context 'when running on a Geo primary node' do
+      before do
+        stub_primary_node
+        allow(Gitlab::Geo).to receive(:secondary_nodes) { [double] }
+      end
+
+      it 'creates Geo cache invalidation event' do
+        expect do
+          post api("/features/#{feature_name}", admin), params: { value: 'true' }
+        end.to change(Geo::CacheInvalidationEvent, :count).by(1)
+      end
+    end
+  end
+
+  describe 'DELETE /feature/:name' do
+    let(:feature_name) { 'my_feature' }
+
+    context 'when running on a Geo primary node' do
+      before do
+        stub_primary_node
+        allow(Gitlab::Geo).to receive(:secondary_nodes) { [double] }
+      end
+
+      it 'creates Geo cache invalidation event' do
+        Feature.enable(feature_name)
+
+        expect do
+          delete api("/features/#{feature_name}", admin)
+        end.to change(Geo::CacheInvalidationEvent, :count).by(1)
+      end
+    end
+  end
+end

lib/feature.rb

@@ -18,6 +18,10 @@ class Feature
     superclass.table_name = 'feature_gates'
   end
 
+  class ActiveSupportCacheStoreAdapter < Flipper::Adapters::ActiveSupportCacheStore
+    # overrides methods in EE
+  end
+
   InvalidFeatureFlagError = Class.new(Exception) # rubocop:disable Lint/InheritException
 
   class << self
@@ -160,7 +164,7 @@ class Feature
 
       # Redis L2 cache
       redis_cache_adapter =
-        Flipper::Adapters::ActiveSupportCacheStore.new(
+        ActiveSupportCacheStoreAdapter.new(
           active_record_adapter,
           l2_cache_backend,
           expires_in: 1.hour)
@@ -237,4 +241,4 @@ class Feature
   end
 end
 
-Feature.prepend_if_ee('EE::Feature')
+Feature::ActiveSupportCacheStoreAdapter.prepend_if_ee('EE::Feature::ActiveSupportCacheStoreAdapter')