Add CiBuildDistinctCountMetric instrumentation class

ee/config/metrics/counts_28d/20210216175505_user_container_scanning_jobs.yml

@@ -9,6 +9,9 @@ product_category: container_scanning
 value_type: number
 status: active
 time_frame: 28d
+instrumentation_class: CiBuildDistinctCountMetric
+options:
+  secure_type: container_scanning
 data_source: database
 distribution:
 - ee

ee/config/metrics/counts_all/20210216175501_user_container_scanning_jobs.yml

@@ -9,6 +9,9 @@ product_category: container_scanning
 value_type: number
 status: active
 time_frame: all
+instrumentation_class: CiBuildDistinctCountMetric
+options:
+  secure_type: container_scanning
 data_source: database
 distribution:
 - ee

ee/lib/ee/gitlab/usage_data.rb

@@ -19,7 +19,8 @@ module EE
 
       SECURE_PRODUCT_TYPES = {
         container_scanning: {
-          name: :container_scanning_jobs
+          name: :container_scanning_jobs,
+          instrumentation_class_migrated: true
         },
         dast: {
           name: :dast_jobs
@@ -373,11 +374,18 @@ module EE
             user_preferences_group_overview_security_dashboard: count(::User.active.group_view_security_dashboard.where(time_period))
           }
 
+          time_frame = metric_time_period(time_period)
+
           SECURE_PRODUCT_TYPES.each do |secure_type, attribs|
-            results["#{prefix}#{attribs[:name]}".to_sym] = distinct_count(::Ci::Build.where(name: secure_type).where(time_period),
-                                                                          :user_id,
-                                                                          start: minimum_id(::User),
-                                                                          finish: maximum_id(::User))
+            results["#{prefix}#{attribs[:name]}".to_sym] =
+              if attribs[:instrumentation_class_migrated]
+                add_metric('CiBuildDistinctCountMetric', time_frame: time_frame, options: { secure_type: secure_type })
+              else
+                distinct_count(::Ci::Build.where(name: secure_type).where(time_period),
+                                                                              :user_id,
+                                                                              start: minimum_id(::User),
+                                                                              finish: maximum_id(::User))
+              end
           end
 
           results.merge!(count_secure_user_scans)

ee/lib/gitlab/usage/metrics/instrumentations/ci_build_distinct_count_metric.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Usage
+    module Metrics
+      module Instrumentations
+        class CiBuildDistinctCountMetric < DatabaseMetric
+          operation :distinct_count, column: :user_id
+          cache_start_and_finish_as :ci_build_distinct_count_user
+
+          relation { ::Ci::Build }
+
+          start { ::User.minimum(:id) }
+          finish { ::User.maximum(:id) }
+
+          def initialize(time_frame:, options: {})
+            super
+
+            raise ArgumentError, "secure_type options attribute is required" unless secure_type.present?
+            raise ArgumentError, "Attribute: #{secure_type} it not allowed" unless ::EE::Gitlab::UsageData::SECURE_PRODUCT_TYPES.key?(secure_type.to_sym)
+          end
+
+          private
+
+          def relation
+            super.where(name: secure_type) # rubocop: disable CodeReuse/ActiveRecord
+          end
+
+          def secure_type
+            options[:secure_type]
+          end
+        end
+      end
+    end
+  end
+end

ee/spec/lib/gitlab/usage/metrics/instrumentations/ci_build_distinct_count_metric_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Usage::Metrics::Instrumentations::CiBuildDistinctCountMetric do
+  before_all do
+    user = create(:user)
+    create(:ci_build, name: 'dast')
+    create(:ci_build, name: 'container_scanning', user: user)
+    create(:ci_build, name: 'container_scanning', user: user)
+  end
+
+  it_behaves_like 'a correct instrumented metric value', { time_frame: 'all', data_source: 'database', options: { secure_type: 'container_scanning' } } do
+    let(:expected_value) { 1 }
+  end
+
+  it 'raises an exception if secure_type option is not present' do
+    expect { described_class.new }.to raise_error(ArgumentError)
+  end
+
+  it 'raises an exception if secure_type option is invalid' do
+    expect { described_class.new(option: { secure_type: 'invalid_type' }) }.to raise_error(ArgumentError)
+  end
+
+  context 'with cache_start_and_finish_as called' do
+    before do
+      allow_next_instance_of(Gitlab::Database::BatchCounter) do |batch_counter|
+        allow(batch_counter).to receive(:transaction_open?).and_return(false)
+      end
+    end
+
+    it 'caches using the key name passed', :request_store, :use_clean_rails_redis_caching do
+      expect(Gitlab::Cache).to receive(:fetch_once).with('metric_instrumentation/ci_build_distinct_count_user_minimum_id', any_args).and_call_original
+      expect(Gitlab::Cache).to receive(:fetch_once).with('metric_instrumentation/ci_build_distinct_count_user_maximum_id', any_args).and_call_original
+
+      described_class.new(time_frame: 'all', options: { secure_type: 'container_scanning' }).value
+
+      expect(Rails.cache.read('metric_instrumentation/ci_build_distinct_count_user_minimum_id')).to eq(::User.minimum(:id))
+      expect(Rails.cache.read('metric_instrumentation/ci_build_distinct_count_user_maximum_id')).to eq(::User.maximum(:id))
+    end
+  end
+end