Add dangerbot for Deprecated Redis, RedisHLL and Snowplow tracking

danger/analytics_instrumentation/Dangerfile

@@ -7,3 +7,5 @@ analytics_instrumentation.check!
 analytics_instrumentation.check_affected_scopes!
 
 analytics_instrumentation.check_usage_data_insertions!
+
+analytics_instrumentation.check_deprecated_data_sources!

spec/tooling/danger/analytics_instrumentation_spec.rb

@@ -231,4 +231,64 @@
       end
     end
   end
+
+  describe '#check_deprecated_data_sources!' do
+    let(:fake_project_helper) { instance_double(Tooling::Danger::ProjectHelper) }
+
+    subject(:check_data_source) { analytics_instrumentation.check_deprecated_data_sources! }
+
+    before do
+      allow(fake_helper).to receive(:added_files).and_return([added_file])
+      allow(fake_helper).to receive(:changed_lines).with(added_file).and_return(changed_lines)
+      allow(analytics_instrumentation).to receive(:project_helper).and_return(fake_project_helper)
+      allow(analytics_instrumentation.project_helper).to receive(:file_lines).and_return(changed_lines.map { |line| line.delete_prefix('+') })
+    end
+
+    context 'when no metric definitions were modified' do
+      let(:added_file) { 'app/models/user.rb' }
+      let(:changed_lines) { ['+ data_source: redis,'] }
+
+      it 'does not trigger warning' do
+        expect(analytics_instrumentation).not_to receive(:markdown)
+
+        check_data_source
+      end
+    end
+
+    context 'when metrics fields were modified' do
+      let(:added_file) { 'config/metrics/count7_d/example_metric.yml' }
+
+      [:redis, :redis_hll].each do |source|
+        context "when source is #{source}" do
+          let(:changed_lines) { ["+ data_source: #{source}"] }
+          let(:template) do
+            <<~SUGGEST_COMMENT
+              ```suggestion
+              data_source: internal_events
+              ```
+
+              %<message>s
+            SUGGEST_COMMENT
+          end
+
+          it 'issues a warning' do
+            expected_comment = format(template, message: Tooling::Danger::AnalyticsInstrumentation::CHANGE_DEPRECATED_DATA_SOURCE_MESSAGE)
+            expect(analytics_instrumentation).to receive(:markdown).with(expected_comment.strip, file: added_file, line: 1)
+
+            check_data_source
+          end
+        end
+      end
+
+      context 'when neither redis nor redis_hll used as a data_source' do
+        let(:changed_lines) { ['+ data_source: database,'] }
+
+        it 'does not issue a warning' do
+          expect(analytics_instrumentation).not_to receive(:markdown)
+
+          check_data_source
+        end
+      end
+    end
+  end
 end

tooling/danger/analytics_instrumentation.rb

 # frozen_string_literal: true
 
+require_relative 'suggestor'
+
 module Tooling
   module Danger
     module AnalyticsInstrumentation
+      include ::Tooling::Danger::Suggestor
+
       METRIC_DIRS = %w[lib/gitlab/usage/metrics/instrumentations ee/lib/gitlab/usage/metrics/instrumentations].freeze
       APPROVED_LABEL = 'analytics instrumentation::approved'
       REVIEW_LABEL = 'analytics instrumentation::review pending'
@@ -26,6 +30,10 @@ module AnalyticsInstrumentation
         Please use [Instrumentation Classes](https://docs.gitlab.com/ee/development/service_ping/metrics_instrumentation.html) instead.
       MSG
 
+      CHANGE_DEPRECATED_DATA_SOURCE_MESSAGE = <<~MSG
+        Redis and RedisHLL tracking is deprecated, consider using Internal Events tracking instead https://docs.gitlab.com/ee/development/internal_analytics/internal_event_instrumentation/quick_start.html#defining-event-and-metrics
+      MSG
+
       WORKFLOW_LABELS = [
         APPROVED_LABEL,
         REVIEW_LABEL
@@ -58,6 +66,17 @@ def check_usage_data_insertions!
         warn format(CHANGED_USAGE_DATA_MESSAGE)
       end
 
+      def check_deprecated_data_sources!
+        new_metric_files.each do |filename|
+          add_suggestion(
+            filename: filename,
+            regex: /^\+?\s+data_source: redis\w*/,
+            replacement: 'data_source: internal_events',
+            comment_text: CHANGE_DEPRECATED_DATA_SOURCE_MESSAGE
+          )
+        end
+      end
+
       private
 
       def convert_to_table(items)
@@ -99,6 +118,10 @@ def select_models(files)
         end
       end
 
+      def new_metric_files
+        helper.added_files.select { |f| f.include?('config/metrics') && f.end_with?('.yml') }
+      end
+
       def each_metric(&block)
         METRIC_DIRS.each do |dir|
           Dir.glob(File.join(dir, '*.rb')).each(&block)