Add path to edit custom metrics

This adds a path to edit custom metrics in prometheus dashboard
response. It also adds a boolean to indicate if a panel group contains
custom metrics.

app/services/metrics/dashboard/system_dashboard_service.rb

@@ -11,6 +11,7 @@ module Metrics
       SEQUENCE = [
         STAGES::CommonMetricsInserter,
         STAGES::ProjectMetricsInserter,
+        STAGES::ProjectMetricsDetailsInserter,
         STAGES::EndpointInserter,
         STAGES::Sorter
       ].freeze

changelogs/unreleased/35968-add_path_to_edit_custom_metrics.yml

+---
+title: Adds path to edit custom metrics in dashboard response
+merge_request: 24645
+author:
+type: added

lib/gitlab/metrics/dashboard/stages/project_metrics_details_inserter.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Metrics
+    module Dashboard
+      module Stages
+        class ProjectMetricsDetailsInserter < BaseStage
+          def transform!
+            dashboard[:panel_groups].each do |panel_group|
+              next unless panel_group
+
+              has_custom_metrics = custom_group_titles.include?(panel_group[:group])
+              panel_group[:has_custom_metrics] = has_custom_metrics
+
+              panel_group[:panels].each do |panel|
+                next unless panel
+
+                panel[:metrics].each do |metric|
+                  next unless metric
+
+                  metric[:edit_path] = has_custom_metrics ? edit_path(metric) : nil
+                end
+              end
+            end
+          end
+
+          private
+
+          def custom_group_titles
+            @custom_group_titles ||= PrometheusMetricEnums.custom_group_details.values.map { |group_details| group_details[:group_title] }
+          end
+
+          def edit_path(metric)
+            Gitlab::Routing.url_helpers.edit_project_prometheus_metric_path(project, metric[:metric_id])
+          end
+        end
+      end
+    end
+  end
+end

spec/fixtures/lib/gitlab/metrics/dashboard/schemas/metrics.json

@@ -16,7 +16,8 @@
     "label": { "type": "string" },
     "track": { "type": "string" },
     "prometheus_endpoint_path": { "type": "string" },
-    "metric_id": { "type": "number" }
+    "metric_id": { "type": "number" },
+    "edit_path": { "type": ["string", "null"] }
   },
   "additionalProperties": false
 }

spec/fixtures/lib/gitlab/metrics/dashboard/schemas/panel_groups.json

@@ -10,7 +10,8 @@
     "panels": {
       "type": "array",
       "items": { "$ref": "panels.json" }
-    }
+    },
+    "has_custom_metrics": { "type": "boolean" }
   },
   "additionalProperties": false
 }

spec/lib/gitlab/metrics/dashboard/processor_spec.rb

@@ -12,6 +12,7 @@ describe Gitlab::Metrics::Dashboard::Processor do
       [
         Gitlab::Metrics::Dashboard::Stages::CommonMetricsInserter,
         Gitlab::Metrics::Dashboard::Stages::ProjectMetricsInserter,
+        Gitlab::Metrics::Dashboard::Stages::ProjectMetricsDetailsInserter,
         Gitlab::Metrics::Dashboard::Stages::EndpointInserter,
         Gitlab::Metrics::Dashboard::Stages::Sorter
       ]
@@ -25,6 +26,10 @@ describe Gitlab::Metrics::Dashboard::Processor do
       end
     end
 
+    it 'includes boolean to indicate if panel group has custom metrics' do
+      expect(dashboard[:panel_groups]).to all(include( { has_custom_metrics: boolean } ))
+    end
+
     context 'when the dashboard is not present' do
       let(:dashboard_yml) { nil }
 
@@ -145,7 +150,8 @@ describe Gitlab::Metrics::Dashboard::Processor do
       unit: metric.unit,
       label: metric.legend,
       metric_id: metric.id,
-      prometheus_endpoint_path: prometheus_path(metric.query)
+      prometheus_endpoint_path: prometheus_path(metric.query),
+      edit_path: edit_metric_path(metric)
     }
   end
 
@@ -165,4 +171,11 @@ describe Gitlab::Metrics::Dashboard::Processor do
       identifier: metric
     )
   end
+
+  def edit_metric_path(metric)
+    Gitlab::Routing.url_helpers.edit_project_prometheus_metric_path(
+      project,
+      metric.id
+    )
+  end
 end