Make EE interactions and transformations cleaner

app/controllers/projects/environments_controller.rb

@@ -10,7 +10,7 @@ class Projects::EnvironmentsController < Projects::ApplicationController
   before_action :environment, only: [:show, :edit, :update, :stop, :terminal, :terminal_websocket_authorize, :metrics]
   before_action :verify_api_request!, only: :terminal_websocket_authorize
   before_action :expire_etag_cache, only: [:index]
-  before_action only: [:metrics, :additional_metrics] do
+  before_action only: [:metrics, :additional_metrics, :metrics_dashboard] do
     push_frontend_feature_flag(:metrics_time_window)
     push_frontend_feature_flag(:environment_metrics_use_prometheus_endpoint)
   end

lib/gitlab/metrics_dashboard/processor.rb

@@ -2,26 +2,33 @@
 
 module Gitlab
   module MetricsDashboard
+    # Responsible for processesing a dashboard hash, inserting
+    # relevantDB records & sorting for proper rendering in
+    # the UI. These includes shared metric info, custom metrics
+    # info, and alerts (only in EE).
     class Processor
-      def initialize(dashboard, project, environment)
-        @dashboard = dashboard.deep_transform_keys(&:to_sym)
+      def initialize(project, environment)
         @project = project
         @environment = environment
       end
 
-      def stages
-        @stages ||= [
+      def sequence
+        [
           Stages::CommonMetricsInserter,
           Stages::ProjectMetricsInserter,
           Stages::Sorter
-        ].freeze
+        ]
       end
 
-      def process
-        stage_params = [@dashboard, @project, @environment]
-        stages.each { |stage| stage.new(*stage_params).transform! }
+      # Returns a new dashboard hash with the results of
+      # running transforms on the dashboard.
+      def process(dashboard)
+        dashboard = dashboard.deep_transform_keys(&:to_sym)
 
-        @dashboard
+        stage_params = [@project, @environment]
+        sequence.each { |stage| stage.new(*stage_params).transform!(dashboard) }
+
+        dashboard
       end
     end
   end

lib/gitlab/metrics_dashboard/service.rb

@@ -28,7 +28,7 @@ module Gitlab
       end
 
       def process_dashboard(dashboard)
-        Processor.new(dashboard, project, params[:environment]).process
+        Processor.new(project, params[:environment]).process(dashboard)
       end
     end
   end

lib/gitlab/metrics_dashboard/stages/base_stage.rb

@@ -6,10 +6,9 @@ module Gitlab
       class BaseStage
         DEFAULT_PANEL_TYPE = 'area-chart'
 
-        attr_reader :dashboard, :project, :environment
+        attr_reader :project, :environment
 
-        def initialize(dashboard, project, environment)
-          @dashboard = dashboard
+        def initialize(project, environment)
           @project = project
           @environment = environment
         end
@@ -18,13 +17,13 @@ module Gitlab
         # @param dashboard [Hash]
         # @param project [Project]
         # @param environment [Environment]
-        def transform!
+        def transform!(_dashboard)
           raise NotImplementedError
         end
 
         protected
 
-        def for_metrics
+        def for_metrics(dashboard)
           dashboard[:panel_groups].each do |panel_group|
             panel_group[:panels].each do |panel|
               panel[:metrics].each do |metric|

lib/gitlab/metrics_dashboard/stages/common_metrics_inserter.rb

@@ -7,10 +7,10 @@ module Gitlab
         # For each metric in the dashboard config, attempts to
         # find a corresponding database record. If found,
         # includes the record's id in the dashboard config.
-        def transform!
+        def transform!(dashboard)
           common_metrics = ::PrometheusMetric.common
 
-          for_metrics do |metric|
+          for_metrics(dashboard) do |metric|
             metric_record = common_metrics.find { |m| m.identifier == metric[:id] }
             metric[:metric_id] = metric_record.id if metric_record
           end

lib/gitlab/metrics_dashboard/stages/project_metrics_inserter.rb

@@ -7,7 +7,7 @@ module Gitlab
         # Inserts project-specific metrics into the dashboard
         # config. If there are no project-specific metrics,
         # this will have no effect.
-        def transform!
+        def transform!(dashboard)
           project.prometheus_metrics.each do |project_metric|
             group = find_or_create_panel_group(dashboard[:panel_groups], project_metric)
             panel = find_or_create_panel(group[:panels], project_metric)

lib/gitlab/metrics_dashboard/stages/sorter.rb

@@ -4,20 +4,20 @@ module Gitlab
   module MetricsDashboard
     module Stages
       class Sorter < BaseStage
-        def transform!
-          sort_groups!
-          sort_panels!
+        def transform!(dashboard)
+          sort_groups!(dashboard)
+          sort_panels!(dashboard)
         end
 
         private
 
         # Sorts the groups in the dashboard by the :priority key
-        def sort_groups!
+        def sort_groups!(dashboard)
           dashboard[:panel_groups] = dashboard[:panel_groups].sort_by { |group| -group[:priority].to_i }
         end
 
         # Sorts the panels in the dashboard by the :weight key
-        def sort_panels!
+        def sort_panels!(dashboard)
           dashboard[:panel_groups].each do |group|
             group[:panels] = group[:panels].sort_by { |panel| -panel[:weight].to_i }
           end

spec/lib/gitlab/metrics_dashboard/processor_spec.rb

@@ -8,8 +8,8 @@ describe Gitlab::MetricsDashboard::Processor do
   let(:dashboard_yml) { YAML.load_file('spec/fixtures/lib/gitlab/metrics_dashboard/sample_dashboard.yml') }
 
   describe 'process' do
-    let(:process_params) { [dashboard_yml, project, environment] }
-    let(:dashboard) { described_class.new(*process_params).process }
+    let(:process_params) { [project, environment] }
+    let(:dashboard) { described_class.new(*process_params).process(dashboard_yml) }
 
     context 'when dashboard config corresponds to common metrics' do
       let!(:common_metric) { create(:prometheus_metric, :common, identifier: 'metric_a1') }