Add usage data collection to geo secondaries

- Add a cron worker to collect and update the secondary usage data table
- Add a placeholder that does the data collection
- Add a new cron to cron_manager and settings, running weekly on Sunday.

Relates to https://gitlab.com/gitlab-org/gitlab/issues/323220

config/initializers/1_settings.rb

@@ -586,6 +586,9 @@ Gitlab.ee do
   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_secondary_usage_data_cron_worker'] ||= Settingslogic.new({})
+  Settings.cron_jobs['geo_secondary_usage_data_cron_worker']['cron'] ||= '0 0 * * 0'
+  Settings.cron_jobs['geo_secondary_usage_data_cron_worker']['job_class'] ||= 'Geo::SecondaryUsageDataCronWorker'
   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/geo/secondary_usage_data.rb

@@ -23,4 +23,8 @@ class Geo::SecondaryUsageData < Geo::TrackingBase
       end
     end
   end
+
+  def self.update_metrics!
+    # This should go through and collect metrics
+  end
 end

ee/app/workers/all_queues.yml

@@ -195,6 +195,14 @@
   :weight: 1
   :idempotent: true
   :tags: []
+- :name: cronjob:geo_secondary_usage_data_cron
+  :feature_category: :geo_replication
+  :has_external_dependencies:
+  :urgency: :low
+  :resource_boundary: :unknown
+  :weight: 1
+  :idempotent:
+  :tags: []
 - :name: cronjob:geo_sidekiq_cron_config
   :feature_category: :geo_replication
   :has_external_dependencies:

ee/app/workers/geo/secondary_usage_data_cron_worker.rb

+# frozen_string_literal: true
+
+module Geo
+  class SecondaryUsageDataCronWorker # rubocop:disable Scalability/IdempotentWorker
+    LEASE_TIMEOUT = 24.hours.freeze
+
+    include ApplicationWorker
+    include CronjobQueue # rubocop:disable Scalability/CronWorkerContext
+    include ::Gitlab::Geo::LogHelpers
+    include ExclusiveLeaseGuard
+
+    feature_category :geo_replication
+
+    def perform
+      return unless Gitlab::Geo.secondary?
+      return unless Feature.enabled?(:geo_secondary_usage_data_collection)
+
+      try_obtain_lease do
+        SecondaryUsageData.update_metrics!
+      end
+    end
+
+    private
+
+    def lease_timeout
+      LEASE_TIMEOUT
+    end
+
+    def lease_release?
+      false
+    end
+  end
+end

ee/config/feature_flags/development/geo_secondary_usage_data_collection.yml

+---
+name: geo_secondary_usage_data_collection
+introduced_by_url:
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/322628
+milestone: '13.10'
+type: development
+group: group::geo
+default_enabled: false

ee/lib/gitlab/geo/cron_manager.rb

@@ -21,6 +21,7 @@ module Gitlab
         geo_container_repository_sync_worker
         geo_repository_verification_secondary_scheduler_worker
         geo_secondary_registry_consistency_worker
+        geo_secondary_usage_data_cron_worker
       ].freeze
 
       GEO_JOBS = (COMMON_JOBS + PRIMARY_JOBS + SECONDARY_JOBS).freeze

ee/spec/lib/gitlab/geo/cron_manager_spec.rb

@@ -17,6 +17,7 @@ RSpec.describe Gitlab::Geo::CronManager, :geo do
     geo_metrics_update_worker
     geo_prune_event_log_worker
     geo_verification_cron_worker
+    geo_secondary_usage_data_cron_worker
   ].freeze
 
   def job(name)
@@ -39,7 +40,8 @@ RSpec.describe Gitlab::Geo::CronManager, :geo do
         job('geo_registry_sync_worker'),
         job('geo_repository_sync_worker'),
         job('geo_container_repository_sync_worker'),
-        job('geo_repository_verification_secondary_scheduler_worker')
+        job('geo_repository_verification_secondary_scheduler_worker'),
+        job('geo_secondary_usage_data_cron_worker')
       ]
     end
 

ee/spec/workers/geo/secondary_usage_data_cron_worker_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Geo::SecondaryUsageDataCronWorker, :clean_gitlab_redis_shared_state do
+  include ::EE::GeoHelpers
+
+  before do
+    allow(subject).to receive(:try_obtain_lease).and_yield
+    allow(Geo::SecondaryUsageData).to receive(:update_metrics!)
+    stub_secondary_node
+  end
+
+  it 'uses a cronjob queue' do
+    expect(subject.sidekiq_options_hash).to include(
+      'queue' => 'cronjob:geo_secondary_usage_data_cron',
+      'queue_namespace' => :cronjob
+    )
+  end
+
+  it 'does not run for primary nodes' do
+    allow(Gitlab::Geo).to receive(:secondary?).and_return(false)
+    expect(Geo::SecondaryUsageData).not_to receive(:update_metrics!)
+
+    subject.perform
+  end
+
+  it 'calls SecondaryUsageData update metrics when it obtains the lease' do
+    expect(subject).to receive(:try_obtain_lease).and_yield
+    expect(Geo::SecondaryUsageData).to receive(:update_metrics!)
+
+    subject.perform
+  end
+
+  it "does not update metrics if it doesn't obtain the lease" do
+    expect(subject).to receive(:try_obtain_lease).and_return(false)
+    expect(Geo::SecondaryUsageData).not_to receive(:update_metrics!)
+
+    subject.perform
+  end
+end