Merge branch 'mwaw/product_analytics_aggregated_metrics_with_feature_flags' into 'master'

Add feature flag mechanism to aggregated metrics

See merge request gitlab-org/gitlab!47534

doc/development/product_analytics/usage_ping.md

@@ -737,13 +737,20 @@ In order to add data for aggregated metrics into Usage Ping payload you should a
 - operator: operator that defines how aggregated metric data will be counted. Available operators are:
   - `ANY`: removes duplicates and counts all entries that triggered any of listed events
 - events: list of events names (from [`known_events.yml`](#known-events-in-usage-data-payload)) to aggregate into metric. All events in this list must have the same `redis_slot` and `aggregation` attributes.
+- feature_flag: name of [development feature flag](../feature_flags/development.md#development-type) that will be checked before
+metrics aggregation is performed. Corresponding feature flag should have `default_enabled` attribute set to `false`. 
+`feature_flag` attribute is **OPTIONAL**  and can be omitted, when `feature_flag` is missing no feature flag will be checked.
 
-Example aggregated metric entry:
+Example aggregated metric entries:
 
 ```yaml
 - name: example_aggregated_metric
+  operator: ANY
+  events: ['i_search_advanced', 'i_search_paid']
+- name: example_aggregated_metric_with_feautre_flag
   operator: ANY
   events: ['i_search_total', 'i_search_advanced', 'i_search_paid']
+  feature_flag: example_aggregated_metric
 ```
 
 Aggregated metrics will be added under `aggregated_metrics` key in both `counts_weekly` and `counts_monthly` top level keys in Usage Ping payload.

lib/gitlab/usage_data_counters/aggregated_metrics/common.yml

@@ -4,10 +4,15 @@
 #             - "ALL": counts unique elements that were observed triggering all of following events
 #  events: list of events names to aggregate into metric. All events in this list must have the same 'redis_slot' and 'aggregation' attributes
 #           see from lib/gitlab/usage_data_counters/known_events/ for the list of valid events.
+#  feature_flag: name of development feature flag that will be checked before metrics aggregation is performed.
+#                Corresponding feature flag should have `default_enabled` attribute set to `false`.
+#                This attribute is OPTIONAL and can be omitted, when `feature_flag` is missing no feature flag will be checked.
 ---
 - name: product_analytics_test_aggregated_metrics
   operator: ANY
   events: ['i_search_total', 'i_search_advanced', 'i_search_paid']
+  feature_flag: product_analytics_aggregated_metrics
 - name: product_analytics_test_combined_events
   operator: ALL
   events: ['i_search_total', 'i_search_advanced', 'i_search_paid']
+  feature_flag: product_analytics_aggregated_metrics

lib/gitlab/usage_data_counters/hll_redis_counter.rb

@@ -97,15 +97,11 @@ module Gitlab
         end
 
         def aggregated_metrics_monthly_data
-          aggregated_metrics.to_h do |aggregation|
-            [aggregation[:name], calculate_count_for_aggregation(aggregation, start_date: 4.weeks.ago.to_date, end_date: Date.current)]
-          end
+          aggregated_metrics_data(4.weeks.ago.to_date)
         end
 
         def aggregated_metrics_weekly_data
-          aggregated_metrics.to_h do |aggregation|
-            [aggregation[:name], calculate_count_for_aggregation(aggregation, start_date: 7.days.ago.to_date, end_date: Date.current)]
-          end
+          aggregated_metrics_data(7.days.ago.to_date)
         end
 
         def known_events
@@ -132,6 +128,14 @@ module Gitlab
           Plan.all_plans
         end
 
+        def aggregated_metrics_data(start_date)
+          aggregated_metrics.each_with_object({}) do |aggregation, weekly_data|
+            next if aggregation[:feature_flag] && Feature.disabled?(aggregation[:feature_flag], default_enabled: false, type: :development)
+
+            weekly_data[aggregation[:name]] = calculate_count_for_aggregation(aggregation, start_date: start_date, end_date: Date.current)
+          end
+        end
+
         def calculate_count_for_aggregation(aggregation, start_date:, end_date:)
           case aggregation[:operator]
           when UNION_OF_AGGREGATED_METRICS

spec/lib/gitlab/usage_data_counters/aggregated_metrics_spec.rb

@@ -33,7 +33,7 @@ RSpec.describe 'aggregated metrics' do
         end
 
         it "has expected structure" do
-          expect(aggregate.keys).to match_array(%w[name operator events])
+          expect(aggregate.keys).to include(*%w[name operator events])
         end
 
         it "uses allowed aggregation operators" do

spec/lib/gitlab/usage_data_counters/hll_redis_counter_spec.rb

@@ -441,6 +441,28 @@ RSpec.describe Gitlab::UsageDataCounters::HLLRedisCounter, :clean_gitlab_redis_s
             expect(aggregated_metrics_data).to eq(results)
           end
         end
+
+        context 'hidden behind feature flag' do
+          let(:enabled_feature_flag) { 'test_ff_enabled' }
+          let(:disabled_feature_flag) { 'test_ff_disabled' }
+          let(:aggregated_metrics) do
+            [
+              # represents stable aggregated metrics that has been fully released
+              { name: 'gmau_without_ff', events: %w[event3_slot event5_slot], operator: "ANY" },
+              # represents new aggregated metric that is under performance testing on gitlab.com
+              { name: 'gmau_enabled', events: %w[event4], operator: "ALL", feature_flag: enabled_feature_flag },
+              # represents aggregated metric that is under development and shouldn't be yet collected even on gitlab.com
+              { name: 'gmau_disabled', events: %w[event4], operator: "ALL", feature_flag: disabled_feature_flag }
+            ].map(&:with_indifferent_access)
+          end
+
+          it 'returns the number of unique events for all known events' do
+            skip_feature_flags_yaml_validation
+            stub_feature_flags(enabled_feature_flag => true, disabled_feature_flag => false)
+
+            expect(aggregated_metrics_data).to eq('gmau_without_ff' => 2, 'gmau_enabled' => 3)
+          end
+        end
       end
     end