Squashed commit of the following:

commit 637c9558
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Mon Feb 26 12:40:40 2018 +0100

    Fix failing test, when deployment platform is not bound to a cluster.

commit 0feeddaa
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Sat Feb 24 01:06:08 2018 +0100

    drop the ! from synchronize_service_state! + remove unused scope

commit 22e2cad9
Author: Pawel Chojnacki <pawel@chojnacki.ws>
Date:   Sat Feb 24 00:56:50 2018 +0100

    Use deployment platform to find cluster with prometheus application

app/models/clusters/cluster.rb

@@ -51,8 +51,6 @@ module Clusters
     scope :enabled, -> { where(enabled: true) }
     scope :disabled, -> { where(enabled: false) }
 
-    scope :for_environment, -> (env) { where(environment_scope: ['*', '', env.slug]) }
-
     def status_name
       if provider
         provider.status_name

app/models/environment.rb

@@ -241,12 +241,12 @@ class Environment < ActiveRecord::Base
   end
 
   def cluster_prometheus_adapter
-    # sort results by descending order based on environment_scope being longer
-    # thus more closely matching environment slug
-    clusters = project.clusters.enabled.for_environment(self).sort_by { |c| c.environment_scope&.length }.reverse!
+    return unless project.deployment_platform.respond_to?(:cluster)
 
-    cluster = clusters&.detect { |cluster| cluster.application_prometheus&.installed? }
-    cluster&.application_prometheus
+    cluster = project.deployment_platform.cluster
+    return unless cluster.application_prometheus&.installed?
+
+    cluster.application_prometheus
   end
 
   private

app/models/project_services/prometheus_service.rb

@@ -9,7 +9,7 @@ class PrometheusService < MonitoringService
     validates :api_url, url: true
   end
 
-  before_save :synchronize_service_state!
+  before_save :synchronize_service_state
 
   after_save :clear_reactive_cache!
 
@@ -82,7 +82,7 @@ class PrometheusService < MonitoringService
 
   private
 
-  def synchronize_service_state!
+  def synchronize_service_state
     self.active = prometheus_installed? || manual_configuration?
 
     true

spec/models/environment_spec.rb

 require 'spec_helper'
 
 describe Environment do
-  set(:project) { create(:project) }
+  let(:project) { create(:project) }
   subject(:environment) { create(:environment, project: project) }
 
   it { is_expected.to belong_to(:project) }
@@ -724,10 +724,7 @@ describe Environment do
   end
 
   describe '#prometheus_adapter' do
-    let!(:cluster_for_all) { create(:cluster, environment_scope: '*', projects: [project]) }
-    let!(:cluster_for_dev) { create(:cluster, environment_scope: 'dev', projects: [project]) }
-
-    let!(:prometheus_for_dev) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_dev) }
+    let(:cluster) { create(:cluster, :provided_by_user, environment_scope: '*', projects: [project]) }
 
     context 'prometheus service can execute queries' do
       let(:prometheus_service) { double(:prometheus_service, can_query?: true) }
@@ -744,53 +741,17 @@ describe Environment do
     context "prometheus service can't execute queries" do
       let(:prometheus_service) { double(:prometheus_service, can_query?: false) }
 
-      context 'with cluster for all environments with prometheus installed' do
-        let!(:prometheus_for_all) { create(:clusters_applications_prometheus, :installed, cluster: cluster_for_all) }
-
-        context 'without environment supplied' do
-          it 'returns application handling all environments' do
-            expect(environment.prometheus_adapter).to eq(prometheus_for_all)
-          end
-        end
-
-        context 'with dev environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'dev') }
+      context 'with cluster with prometheus installed' do
+        let!(:prometheus) { create(:clusters_applications_prometheus, :installed, cluster: cluster) }
 
-          it 'returns dev cluster prometheus application' do
-            expect(environment.prometheus_adapter).to eq(prometheus_for_dev)
-          end
-        end
-
-        context 'with prod environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'prod') }
-
-          it 'returns application handling all environments' do
-            expect(environment.prometheus_adapter).to eq(prometheus_for_all)
-          end
+        it 'returns application handling all environments' do
+          expect(environment.prometheus_adapter).to eq(prometheus)
         end
       end
 
-      context 'with cluster for all environments without prometheus installed' do
-        context 'without environment supplied' do
-          it 'returns nil' do
-            expect(environment.prometheus_adapter).to be_nil
-          end
-        end
-
-        context 'with dev environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'dev') }
-
-          it 'returns dev cluster prometheus application' do
-            expect(environment.prometheus_adapter).to eq(prometheus_for_dev)
-          end
-        end
-
-        context 'with prod environment supplied' do
-          let!(:environment) { create(:environment, project: project, name: 'prod') }
-
-          it 'returns nil' do
-            expect(environment.prometheus_adapter).to be_nil
-          end
+      context 'with cluster without prometheus installed' do
+        it 'returns nil' do
+          expect(environment.prometheus_adapter).to be_nil
         end
       end
     end

spec/models/project_services/prometheus_service_spec.rb

@@ -221,7 +221,7 @@ describe PrometheusService, :use_clean_rails_memory_store_caching do
     end
   end
 
-  describe '#synchronize_service_state! before_save callback' do
+  describe '#synchronize_service_state before_save callback' do
     context 'no clusters with prometheus are installed' do
       context 'when service is inactive' do
         before do