Adding metrics for MRs with CODEOWNER approvals

This is pretty similar to the code for counting
projects with code owners, but the merge request
model needs the `UsageStatistics` module.

ee/app/models/approval_merge_request_rule.rb

@@ -3,6 +3,7 @@
 class ApprovalMergeRequestRule < ApplicationRecord
   include Gitlab::Utils::StrongMemoize
   include ApprovalRuleLike
+  include EE::UsageStatistics # rubocop: disable Cop/InjectEnterpriseEditionModule
 
   scope :not_matching_pattern, -> (pattern) { code_owner.where.not(name: pattern) }
   scope :matching_pattern, -> (pattern) { code_owner.where(name: pattern) }
@@ -22,6 +23,8 @@ class ApprovalMergeRequestRule < ApplicationRecord
       query
     end
   end
+  scope :code_owner_approval_optional, -> { code_owner.where(approvals_required: 0) }
+  scope :code_owner_approval_required, -> { code_owner.where('approvals_required > 0') }
 
   validates :name, uniqueness: { scope: [:merge_request_id, :rule_type] }
   validates :rule_type, uniqueness: { scope: :merge_request_id, message: proc { _('any-approver for the merge request already exists') } }, if: :any_approver?

ee/changelogs/unreleased/13064-add-count-of-projects-with-codeowners-file-to-usage-ping.yml

+---
+title: Adding CODEOWNER approval metrics for merge requests
+merge_request: 25386
+author:
+type: added

ee/lib/ee/gitlab/usage_data.rb

@@ -147,6 +147,8 @@ module EE
                                          ldap_users: count(::User.ldap, 'users.id'),
                                          pod_logs_usages_total: ::Gitlab::UsageCounters::PodLogs.usage_totals[:total],
                                          projects_enforcing_code_owner_approval: count(::Project.without_deleted.non_archived.requiring_code_owner_approval, batch: false),
+                                         merge_requests_with_optional_codeowners: distinct_count(::ApprovalMergeRequestRule.code_owner_approval_optional, :merge_request_id),
+                                         merge_requests_with_required_codeowners: distinct_count(::ApprovalMergeRequestRule.code_owner_approval_required, :merge_request_id),
                                          projects_mirrored_with_pipelines_enabled: count(::Project.mirrored_with_enabled_pipelines, batch: false),
                                          projects_reporting_ci_cd_back_to_github: count(::GithubService.without_defaults.active, batch: false),
                                          projects_with_packages: count(::Packages::Package.select('distinct project_id'), batch: false),
@@ -221,6 +223,8 @@ module EE
             keys: distinct_count(::Key.regular_keys.where(time_period), :user_id),
             merge_requests: distinct_count(::MergeRequest.where(time_period), :author_id),
             projects_enforcing_code_owner_approval: distinct_count(::Project.requiring_code_owner_approval.where(time_period), :creator_id),
+            merge_requests_with_optional_codeowners: distinct_count(::ApprovalMergeRequestRule.code_owner_approval_optional.where(time_period), :merge_request_id),
+            merge_requests_with_required_codeowners: distinct_count(::ApprovalMergeRequestRule.code_owner_approval_required.where(time_period), :merge_request_id),
             projects_imported_from_github: distinct_count(::Project.github_imported.where(time_period), :creator_id),
             projects_with_repositories_enabled: distinct_count(::Project.with_repositories_enabled.where(time_period), :creator_id),
             protected_branches: distinct_count(::Project.with_protected_branches.where(time_period), :creator_id),

ee/spec/lib/ee/gitlab/usage_data_spec.rb

@@ -132,24 +132,30 @@ describe Gitlab::UsageData do
                   user = create(:user)
                   project = create(:project, :repository_private, :github_imported,
                                    :test_repo, :remote_mirror, creator: user)
+                  merge_request = create(:merge_request, source_project: project)
                   create(:deploy_key, user: user)
                   create(:key, user: user)
-                  create(:merge_request, source_project: project)
                   create(:project, creator: user)
                   create(:protected_branch, project: project)
                   create(:remote_mirror, project: project)
                   create(:snippet, author: user)
                   create(:suggestion, note: create(:note, project: project))
+                  create(:code_owner_rule, merge_request: merge_request, approvals_required: 3)
+                  create(:code_owner_rule, merge_request: merge_request, approvals_required: 7)
+                  create_list(:code_owner_rule, 3, approvals_required: 2)
+                  create_list(:code_owner_rule, 2)
                 end
               end
 
               expect(described_class.uncached_data[:usage_activity_by_stage][:create]).to eq(
                 deploy_keys: 2,
                 keys: 2,
-                merge_requests: 2,
+                merge_requests: 12,
                 projects_enforcing_code_owner_approval: 0,
+                merge_requests_with_optional_codeowners: 4,
+                merge_requests_with_required_codeowners: 8,
                 projects_imported_from_github: 2,
-                projects_with_repositories_enabled: 2,
+                projects_with_repositories_enabled: 12,
                 protected_branches: 2,
                 remote_mirrors: 2,
                 snippets: 2,
@@ -158,10 +164,12 @@ describe Gitlab::UsageData do
               expect(described_class.uncached_data[:usage_activity_by_stage_monthly][:create]).to eq(
                 deploy_keys: 1,
                 keys: 1,
-                merge_requests: 1,
+                merge_requests: 6,
                 projects_enforcing_code_owner_approval: 0,
+                merge_requests_with_optional_codeowners: 2,
+                merge_requests_with_required_codeowners: 4,
                 projects_imported_from_github: 1,
-                projects_with_repositories_enabled: 1,
+                projects_with_repositories_enabled: 6,
                 protected_branches: 1,
                 remote_mirrors: 1,
                 snippets: 1,