New created projects could inherit services from groups

We can now save integrations that belongs to a group
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/39959.

When creating a new project, the precedence to create new integrations
is: closest integration from ancestors to the project, instance-level
integration or template service.

app/models/service.rb

@@ -8,6 +8,7 @@ class Service < ApplicationRecord
   include ProjectServicesLoggable
   include DataFields
   include IgnorableColumns
+  include FromUnion
 
   ignore_columns %i[default], remove_with: '13.5', remove_after: '2020-10-22'
 
@@ -227,7 +228,8 @@ class Service < ApplicationRecord
 
     service.template = false
     service.instance = false
-    service.inherit_from_id = integration.id if integration.instance?
+    service.group = nil
+    service.inherit_from_id = integration.id if integration.instance? || integration.group
     service.project_id = project_id
     service.active = false if service.invalid?
     service

app/services/projects/create_service.rb

@@ -162,7 +162,7 @@ module Projects
 
         if @project.save
           unless @project.gitlab_project_import?
-            create_services_from_active_instances_or_templates(@project)
+            create_services_from_active_default_integrations_or_templates(@project)
             @project.create_labels
           end
 
@@ -229,14 +229,25 @@ module Projects
     private
 
     # rubocop: disable CodeReuse/ActiveRecord
-    def create_services_from_active_instances_or_templates(project)
-      Service.active.where(instance: true).or(Service.active.where(template: true)).group_by(&:type).each do |type, records|
-        service = records.find(&:instance?) || records.find(&:template?)
-        Service.build_from_integration(project.id, service).save!
+    def create_services_from_active_default_integrations_or_templates(project)
+      group_ids = project.ancestors.select(:id)
+
+      Service.from_union([
+        Service.active.where(instance: true),
+        Service.active.where(template: true),
+        Service.active.where(group_id: group_ids)
+      ]).order(by_type_group_ids_and_instance(group_ids)).group_by(&:type).each do |type, records|
+        Service.build_from_integration(project.id, records.first).save!
       end
     end
     # rubocop: enable CodeReuse/ActiveRecord
 
+    def by_type_group_ids_and_instance(group_ids)
+      array = group_ids.to_sql.present? ? "array(#{group_ids.to_sql})" : 'ARRAY[]'
+
+      Arel.sql("type ASC, array_position(#{array}::bigint[], services.group_id), instance DESC")
+    end
+
     def project_namespace
       @project_namespace ||= Namespace.find_by_id(@params[:namespace_id]) || current_user.namespace
     end

spec/models/service_spec.rb

@@ -327,7 +327,7 @@ RSpec.describe Service do
         end
       end
 
-      context 'when integration is an instance' do
+      context 'when integration is an instance-level integration' do
         let(:integration) { create(:jira_service, :instance) }
 
         it 'sets inherit_from_id from integration' do
@@ -337,6 +337,16 @@ RSpec.describe Service do
         end
       end
 
+      context 'when integration is a group-level integration' do
+        let(:integration) { create(:jira_service, group: group, project: nil) }
+
+        it 'sets inherit_from_id from integration' do
+          service = described_class.build_from_integration(project.id, integration)
+
+          expect(service.inherit_from_id).to eq(integration.id)
+        end
+      end
+
       describe 'build issue tracker from an integration' do
         let(:url) { 'http://jira.example.com' }
         let(:api_url) { 'http://api-jira.example.com' }
@@ -360,6 +370,8 @@ RSpec.describe Service do
             expect(service.password).to eq(password)
             expect(service.template).to eq(false)
             expect(service.instance).to eq(false)
+            expect(service.project).to eq(project)
+            expect(service.group).to eq(nil)
           end
         end
 

spec/services/projects/create_service_spec.rb

@@ -487,18 +487,7 @@ RSpec.describe Projects::CreateService, '#execute' do
   describe 'create service for the project' do
     subject(:project) { create_project(user, opts) }
 
-    context 'when there is an active instance-level and an active template integration' do
-      let!(:template_integration) { create(:prometheus_service, :template, api_url: 'https://prometheus.template.com/') }
-      let!(:instance_integration) { create(:prometheus_service, :instance, api_url: 'https://prometheus.instance.com/') }
-
-      it 'creates a service from the instance-level integration' do
-        expect(project.services.count).to eq(1)
-        expect(project.services.first.api_url).to eq(instance_integration.api_url)
-        expect(project.services.first.inherit_from_id).to eq(instance_integration.id)
-      end
-    end
-
-    context 'when there is an active service template' do
+    context 'with an active service template' do
       let!(:template_integration) { create(:prometheus_service, :template, api_url: 'https://prometheus.template.com/') }
 
       it 'creates a service from the template' do
@@ -506,6 +495,60 @@ RSpec.describe Projects::CreateService, '#execute' do
         expect(project.services.first.api_url).to eq(template_integration.api_url)
         expect(project.services.first.inherit_from_id).to be_nil
       end
+
+      context 'with an active instance-level integration' do
+        let!(:instance_integration) { create(:prometheus_service, :instance, api_url: 'https://prometheus.instance.com/') }
+
+        it 'creates a service from the instance-level integration' do
+          expect(project.services.count).to eq(1)
+          expect(project.services.first.api_url).to eq(instance_integration.api_url)
+          expect(project.services.first.inherit_from_id).to eq(instance_integration.id)
+        end
+
+        context 'with an active group-level integration' do
+          let!(:group_integration) { create(:prometheus_service, group: group, project: nil, api_url: 'https://prometheus.group.com/') }
+          let!(:group) do
+            create(:group).tap do |group|
+              group.add_owner(user)
+            end
+          end
+
+          let(:opts) do
+            {
+              name: 'GitLab',
+              namespace_id: group.id
+            }
+          end
+
+          it 'creates a service from the group-level integration' do
+            expect(project.services.count).to eq(1)
+            expect(project.services.first.api_url).to eq(group_integration.api_url)
+            expect(project.services.first.inherit_from_id).to eq(group_integration.id)
+          end
+
+          context 'with an active subgroup' do
+            let!(:subgroup_integration) { create(:prometheus_service, group: subgroup, project: nil, api_url: 'https://prometheus.subgroup.com/') }
+            let!(:subgroup) do
+              create(:group, parent: group).tap do |subgroup|
+                subgroup.add_owner(user)
+              end
+            end
+
+            let(:opts) do
+              {
+                name: 'GitLab',
+                namespace_id: subgroup.id
+              }
+            end
+
+            it 'creates a service from the group-level integration' do
+              expect(project.services.count).to eq(1)
+              expect(project.services.first.api_url).to eq(subgroup_integration.api_url)
+              expect(project.services.first.inherit_from_id).to eq(subgroup_integration.id)
+            end
+          end
+        end
+      end
     end
 
     context 'when there is an invalid integration' do