Refactor Prometheus Adapter to take in cluster

This allows us the choice not to call project.deployment_platform which
could be incorrect if that is called after the deployment has been done.

app/controllers/projects/prometheus/metrics_controller.rb

@@ -23,7 +23,7 @@ module Projects
       private
 
       def prometheus_adapter
-        @prometheus_adapter ||= ::Prometheus::AdapterService.new(project).prometheus_adapter
+        @prometheus_adapter ||= ::Prometheus::AdapterService.new(project, project.deployment_platform&.cluster).prometheus_adapter
       end
 
       def require_prometheus_metrics!

app/models/environment.rb

@@ -223,7 +223,7 @@ class Environment < ApplicationRecord
 
   # rubocop: disable CodeReuse/ServiceClass
   def prometheus_adapter
-    @prometheus_adapter ||= Prometheus::AdapterService.new(project, deployment_platform).prometheus_adapter
+    @prometheus_adapter ||= Prometheus::AdapterService.new(project, deployment_platform&.cluster).prometheus_adapter
   end
   # rubocop: enable CodeReuse/ServiceClass
 

app/services/prometheus/adapter_service.rb

@@ -2,18 +2,13 @@
 
 module Prometheus
   class AdapterService
-    def initialize(project, deployment_platform = nil)
-      @project = project
+    attr_reader :project, :cluster
 
-      @deployment_platform = if deployment_platform
-                               deployment_platform
-                             else
-                               project.deployment_platform
-                             end
+    def initialize(project, cluster)
+      @project = project
+      @cluster = cluster
     end
 
-    attr_reader :deployment_platform, :project
-
     def prometheus_adapter
       @prometheus_adapter ||= if service_prometheus_adapter.can_query?
                                 service_prometheus_adapter
@@ -27,7 +22,7 @@ module Prometheus
     end
 
     def cluster_prometheus_adapter
-      application = deployment_platform&.cluster&.application_prometheus
+      application = cluster&.application_prometheus
 
       application if application&.available?
     end

ee/app/models/ee/environment.rb

@@ -81,7 +81,7 @@ module EE
     end
 
     def cluster_prometheus_adapter
-      @cluster_prometheus_adapter ||= Prometheus::AdapterService.new(project, deployment_platform).cluster_prometheus_adapter
+      @cluster_prometheus_adapter ||= Prometheus::AdapterService.new(project, deployment_platform&.cluster).cluster_prometheus_adapter
     end
 
     def protected?

spec/services/prometheus/adapter_service_spec.rb

@@ -3,13 +3,12 @@
 require 'spec_helper'
 
 describe Prometheus::AdapterService do
-  let(:project) { create(:project) }
+  let_it_be(:project) { create(:project) }
+  let_it_be(:cluster, reload: true) { create(:cluster, :provided_by_user, environment_scope: '*', projects: [project]) }
 
-  subject { described_class.new(project) }
+  subject { described_class.new(project, cluster) }
 
   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) }