Trigger background verification every minute

The trigger `#trigger_background_verification` will be implemented in
the following commit.

config/initializers/1_settings.rb

@@ -553,6 +553,9 @@ Gitlab.ee do
   Settings.cron_jobs['adjourned_projects_deletion_cron_worker'] ||= Settingslogic.new({})
   Settings.cron_jobs['adjourned_projects_deletion_cron_worker']['cron'] ||= '0 4 * * *'
   Settings.cron_jobs['adjourned_projects_deletion_cron_worker']['job_class'] = 'AdjournedProjectsDeletionCronWorker'
+  Settings.cron_jobs['geo_verification_cron_worker'] ||= Settingslogic.new({})
+  Settings.cron_jobs['geo_verification_cron_worker']['cron'] ||= '* * * * *'
+  Settings.cron_jobs['geo_verification_cron_worker']['job_class'] ||= 'Geo::VerificationCronWorker'
   Settings.cron_jobs['geo_file_download_dispatch_worker'] ||= Settingslogic.new({})
   Settings.cron_jobs['geo_file_download_dispatch_worker']['cron'] ||= '*/1 * * * *'
   Settings.cron_jobs['geo_file_download_dispatch_worker']['job_class'] ||= 'Geo::FileDownloadDispatchWorker'

ee/app/models/concerns/geo/verifiable_replicator.rb

@@ -7,7 +7,10 @@ module Geo
     include Delay
 
     class_methods do
+      extend Gitlab::Utils::Override
+
       # If replication is disabled, then so is verification.
+      override :verification_enabled?
       def verification_enabled?
         enabled? && verification_feature_flag_enabled?
       end
@@ -25,6 +28,13 @@ module Geo
         Feature.enabled?(:geo_framework_verification)
       end
 
+      # Called every minute by VerificationCronWorker
+      def trigger_background_verification
+        return false unless verification_enabled?
+
+        # TODO: ::Geo::VerificationBatchWorker.perform_with_capacity(self)
+      end
+
       def checksummed_count
         # When verification is disabled, this returns nil.
         # Bonus: This causes the progress bar to be hidden.

ee/app/workers/all_queues.yml

@@ -187,6 +187,14 @@
   :weight: 1
   :idempotent:
   :tags: []
+- :name: cronjob:geo_verification_cron
+  :feature_category: :geo_replication
+  :has_external_dependencies:
+  :urgency: :low
+  :resource_boundary: :unknown
+  :weight: 1
+  :idempotent: true
+  :tags: []
 - :name: cronjob:historical_data
   :feature_category: :provision
   :has_external_dependencies:

ee/app/workers/geo/verification_cron_worker.rb

+# frozen_string_literal: true
+
+module Geo
+  # Calls trigger_background_verification on every enabled Replicator class,
+  # every minute.
+  #
+  class VerificationCronWorker
+    include ApplicationWorker
+    include ::Gitlab::Geo::LogHelpers
+
+    # This worker does not perform work scoped to a context
+    include CronjobQueue # rubocop:disable Scalability/CronWorkerContext
+
+    idempotent!
+
+    feature_category :geo_replication
+
+    def perform
+      Gitlab::Geo.verification_enabled_replicator_classes.each do |replicator_class|
+        replicator_class.trigger_background_verification
+      end
+    end
+  end
+end

ee/lib/gitlab/geo.rb

@@ -171,5 +171,9 @@ module Gitlab
     def self.enabled_replicator_classes
       REPLICATOR_CLASSES.select(&:enabled?)
     end
+
+    def self.verification_enabled_replicator_classes
+      REPLICATOR_CLASSES.select(&:verification_enabled?)
+    end
   end
 end

ee/lib/gitlab/geo/replicator.rb

@@ -181,6 +181,11 @@ module Gitlab
         :"geo_#{replicable_name}_replication"
       end
 
+      # Overridden by VerifiableReplicator, if it is included
+      def self.verification_enabled?
+        false
+      end
+
       # @param [ActiveRecord::Base] model_record
       # @param [Integer] model_record_id
       def initialize(model_record: nil, model_record_id: nil)

ee/spec/lib/gitlab/geo_spec.rb

@@ -366,4 +366,33 @@ RSpec.describe Gitlab::Geo, :geo, :request_store do
       end
     end
   end
+
+  describe '.verification_enabled_replicator_classes' do
+    it 'returns an Array of replicator classes' do
+      result = described_class.verification_enabled_replicator_classes
+
+      expect(result).to be_an(Array)
+      expect(result).to include(Geo::PackageFileReplicator)
+    end
+
+    context 'when replication is disabled' do
+      before do
+        stub_feature_flags(geo_package_file_replication: false)
+      end
+
+      it 'does not return the replicator class' do
+        expect(described_class.verification_enabled_replicator_classes).not_to include(Geo::PackageFileReplicator)
+      end
+    end
+
+    context 'when verification is disabled' do
+      before do
+        stub_feature_flags(geo_package_file_verification: false)
+      end
+
+      it 'does not return the replicator class' do
+        expect(described_class.verification_enabled_replicator_classes).not_to include(Geo::PackageFileReplicator)
+      end
+    end
+  end
 end

ee/spec/workers/geo/verification_cron_worker_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Geo::VerificationCronWorker, :geo do
+  describe '#perform' do
+    it 'calls trigger_background_verification on enabled Replicators' do
+      replicator = double('replicator')
+
+      expect(replicator).to receive(:trigger_background_verification)
+      expect(Gitlab::Geo).to receive(:verification_enabled_replicator_classes).and_return([replicator])
+
+      described_class.new.perform
+    end
+  end
+
+  it 'uses a cronjob queue' do
+    expect(subject.sidekiq_options_hash).to include(
+      'queue' => 'cronjob:geo_verification_cron',
+      'queue_namespace' => :cronjob
+    )
+  end
+end