Implemente Prometheus:AdapterService

app/controllers/projects/prometheus/metrics_controller.rb

 module Projects
   module Prometheus
     class MetricsController < Projects::ApplicationController
-      include PrometheusAdapterLocator
-
       before_action :authorize_admin_project!
       before_action :require_prometheus_metrics!
 
@@ -22,6 +20,10 @@ module Projects
 
       private
 
+      def prometheus_adapter
+        @prometheus_adapter ||= Prometheus::AdapterService.new(project).prometheus_adapter
+      end
+
       def require_prometheus_metrics!
         render_404 unless prometheus_adapter.can_query?
       end

app/models/concerns/prometheus_adapter_locator.rb

-module PrometheusAdapterLocator
-  def deployment_platform
-    project.deployment_platform
-  end
-
-  def prometheus_adapter
-    @prometheus_adapter ||= if service_prometheus_adapter.can_query?
-                              service_prometheus_adapter
-                            else
-                              cluster_prometheus_adapter
-                            end
-  end
-
-  def service_prometheus_adapter
-    project.find_or_initialize_service('prometheus')
-  end
-
-  def cluster_prometheus_adapter
-    return unless deployment_platform.respond_to?(:cluster)
-
-    cluster = deployment_platform.cluster
-    return unless cluster.application_prometheus&.installed?
-
-    cluster.application_prometheus
-  end
-end

app/models/environment.rb

 class Environment < ActiveRecord::Base
-  include PrometheusAdapterLocator
-
   # Used to generate random suffixes for the slug
   LETTERS = 'a'..'z'
   NUMBERS = '0'..'9'
@@ -159,6 +157,10 @@ class Environment < ActiveRecord::Base
     prometheus_adapter.query(:additional_metrics_environment, self) if has_metrics?
   end
 
+  def prometheus_adapter
+    @prometheus_adapter ||= Prometheus::AdapterService.new(project, deployment_platform).prometheus_adapter
+  end
+
   def slug
     super.presence || generate_slug
   end

app/services/prometheus/adapter_service.rb

+module Prometheus
+  class AdapterService
+    def initialize(project, deployment_platform = nil)
+      @project = project
+
+      @deployment_platform = if deployment_platform
+                               deployment_platform
+                             else
+                               project.deployment_platform
+                             end
+    end
+
+    attr_reader :deployment_platform, :project
+
+    def prometheus_adapter
+      @prometheus_adapter ||= if service_prometheus_adapter.can_query?
+                                service_prometheus_adapter
+                              else
+                                cluster_prometheus_adapter
+                              end
+    end
+
+    def service_prometheus_adapter
+      project.find_or_initialize_service('prometheus')
+    end
+
+    def cluster_prometheus_adapter
+      return unless deployment_platform.respond_to?(:cluster)
+
+      cluster = deployment_platform.cluster
+      return unless cluster.application_prometheus&.installed?
+
+      cluster.application_prometheus
+    end
+  end
+end

spec/services/prometheus/adapter_service_spec.rb

+require 'spec_helper'
+
+describe Prometheus::AdapterService do
+  let(:project) { create(:project) }
+  subject { described_class.new(project) }
+
+  describe '#prometheus_adapter' do
+    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) }
+
+      before do
+        allow(project).to receive(:find_or_initialize_service).with('prometheus').and_return prometheus_service
+      end
+
+      it 'return prometheus service as prometheus adapter' do
+        expect(subject.prometheus_adapter).to eq(prometheus_service)
+      end
+    end
+
+    context "prometheus service can't execute queries" do
+      let(:prometheus_service) { double(:prometheus_service, can_query?: false) }
+
+      context 'with cluster with prometheus installed' do
+        let!(:prometheus) { create(:clusters_applications_prometheus, :installed, cluster: cluster) }
+
+        it 'returns application handling all environments' do
+          expect(subject.prometheus_adapter).to eq(prometheus)
+        end
+      end
+
+      context 'with cluster without prometheus installed' do
+        it 'returns nil' do
+          expect(subject.prometheus_adapter).to be_nil
+        end
+      end
+    end
+  end
+end