Track metrics dashboard panel type

app/services/metrics/dashboard/base_service.rb

@@ -13,6 +13,7 @@ module Metrics
         STAGES::MetricEndpointInserter,
         STAGES::VariableEndpointInserter,
         STAGES::PanelIdsInserter,
+        STAGES::TrackPanelType,
         STAGES::AlertsInserter,
         STAGES::UrlValidator
       ].freeze

lib/gitlab/metrics/dashboard/stages/track_panel_type.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Metrics
+    module Dashboard
+      module Stages
+        class TrackPanelType < BaseStage
+          def transform!
+            for_panel_groups do |panel_group|
+              for_panels_in(panel_group) do |panel|
+                track_panel_type(panel)
+              end
+            end
+          end
+
+          private
+
+          def track_panel_type(panel)
+            panel_type = panel[:type]
+
+            Gitlab::Tracking.event('MetricsDashboard::Chart', 'chart_rendered', label: 'Chart Type', value: panel_type)
+          end
+        end
+      end
+    end
+  end
+end

spec/lib/gitlab/metrics/dashboard/stages/track_panel_type_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Metrics::Dashboard::Stages::TrackPanelType do
+  include MetricsDashboardHelpers
+
+  let(:project) { build_stubbed(:project) }
+  let(:environment) { build_stubbed(:environment, project: project) }
+
+  describe '#transform!' do
+    subject { described_class.new(project, dashboard, environment: environment) }
+
+    let(:dashboard) { load_sample_dashboard.deep_symbolize_keys }
+
+    it 'creates tracking event' do
+      expect(Gitlab::Tracking).to receive(:event).with('MetricsDashboard::Chart', 'chart_rendered',
+        { label: 'Chart Type', value: 'area-chart' }).at_least(:once)
+
+      subject.transform!
+    end
+  end
+end

spec/services/metrics/dashboard/custom_dashboard_service_spec.rb

@@ -57,6 +57,14 @@ RSpec.describe Metrics::Dashboard::CustomDashboardService, :use_clean_rails_memo
         described_class.new(*service_params).get_dashboard
       end
 
+      it 'tracks panel type' do
+        expect(::Gitlab::Tracking).to receive(:event).with(
+          'MetricsDashboard::Chart', 'chart_rendered', { label: 'Chart Type', value: 'area-chart' }
+        ).at_least(:once)
+
+        described_class.new(*service_params).get_dashboard
+      end
+
       context 'and the dashboard is then deleted' do
         it 'does not return the previously cached dashboard' do
           described_class.new(*service_params).get_dashboard