Access prometheus via cluster_prometheus_adapter

- Update specs
- Delete unnecessary code

app/models/clusters/cluster.rb

@@ -136,7 +136,6 @@ module Clusters
       conditions = { projects: { alerts_service: [:data] } }
       includes(conditions).joins(conditions).where(projects: { id: project_ids })
     end
-    scope :with_deployment_in_environment, -> (environment) { joins(:deployments).merge(Deployment.for_environment(environment)) }
 
     def self.ancestor_clusters_for_clusterable(clusterable, hierarchy_order: :asc)
       return [] if clusterable.is_a?(Instance)

app/services/prometheus/create_default_alerts_service.rb

@@ -53,14 +53,13 @@ module Prometheus
     end
 
     def schedule_prometheus_update
-      clusters = project.all_clusters
-      clusters = clusters.with_application_prometheus
-      clusters = clusters.with_deployment_in_environment(environment)
+      return unless prometheus_application
 
-      clusters.each do |cluster|
-        application = cluster.application_prometheus
-        ::Clusters::Applications::ScheduleUpdateService.new(application, project).execute
-      end
+      ::Clusters::Applications::ScheduleUpdateService.new(prometheus_application, project).execute
+    end
+
+    def prometheus_application
+      environment.cluster_prometheus_adapter
     end
 
     def metrics_by_identifier

spec/models/clusters/cluster_spec.rb

@@ -207,24 +207,6 @@ describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
     end
   end
 
-  describe '.with_project_alert_service_data' do
-    subject { described_class.with_deployment_in_environment(environment) }
-
-    let(:project) { create(:project, :repository) }
-    let!(:cluster) { create(:cluster, projects: [project]) }
-    let!(:environment) { create(:environment) }
-
-    context 'deployment in environment' do
-      let!(:deployment) { create(:deployment, cluster: cluster, environment: environment, sha: cluster.project.commit.id) }
-
-      it { is_expected.to include(cluster) }
-    end
-
-    context 'no deployment in environment' do
-      it { is_expected.not_to include(cluster) }
-    end
-  end
-
   describe '.for_project_namespace' do
     subject { described_class.for_project_namespace(namespace_id) }
 

spec/services/prometheus/create_default_alerts_service_spec.rb

@@ -51,23 +51,14 @@ describe Prometheus::CreateDefaultAlertsService do
         end
 
         context 'cluster with prometheus exists' do
-          let!(:cluster) { create(:cluster, :with_installed_prometheus, projects: [project]) }
+          let!(:cluster) { create(:cluster, :with_installed_prometheus, :provided_by_user, projects: [project]) }
 
-          it 'does not schedule an update to prometheus' do
-            expect(::Clusters::Applications::ScheduleUpdateService).not_to receive(:new)
-            execute
-          end
-
-          context 'deployment to relevant environment' do
-            let!(:deployment) { create(:deployment, cluster: cluster, environment: environment, sha: project.commit.id) }
-
-            it 'schedules an update to prometheus' do
-              expect_next_instance_of(::Clusters::Applications::ScheduleUpdateService) do |instance|
-                expect(instance).to receive(:execute)
-              end
-
-              execute
+          it 'schedules an update to prometheus' do
+            expect_next_instance_of(::Clusters::Applications::ScheduleUpdateService) do |instance|
+              expect(instance).to receive(:execute)
             end
+
+            execute
           end
         end