1 files changed, 83 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/dashboard/stages/cluster_endpoint_inserter.rb b/lib/gitlab/metrics/dashboard/stages/cluster_endpoint_inserter.rb
new file mode 100644
index 00000000000..a12082b704c
--- /dev/null
+++ b/lib/gitlab/metrics/dashboard/stages/cluster_endpoint_inserter.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Metrics
+    module Dashboard
+      module Stages
+        class ClusterEndpointInserter < BaseStage
+          def transform!
+            verify_params
+
+            for_metrics do |metric|
+              metric[:prometheus_endpoint_path] = endpoint_for_metric(metric)
+            end
+          end
+
+          private
+
+          def admin_url(metric)
+            Gitlab::Routing.url_helpers.prometheus_api_admin_cluster_path(
+              params[:cluster],
+              proxy_path: query_type(metric),
+              query: query_for_metric(metric)
+            )
+          end
+
+          def endpoint_for_metric(metric)
+            case params[:cluster_type]
+            when :admin
+              admin_url(metric)
+            when :group
+              error!(_('Group is required when cluster_type is :group')) unless params[:group]
+              group_url(metric)
+            when :project
+              error!(_('Project is required when cluster_type is :project')) unless project
+              project_url(metric)
+            else
+              error!(_('Unrecognized cluster type'))
+            end
+          end
+
+          def error!(message)
+            raise Errors::DashboardProcessingError.new(message)
+          end
+
+          def group_url(metric)
+            Gitlab::Routing.url_helpers.prometheus_api_group_cluster_path(
+              params[:group],
+              params[:cluster],
+              proxy_path: query_type(metric),
+              query: query_for_metric(metric)
+            )
+          end
+
+          def project_url(metric)
+            Gitlab::Routing.url_helpers.prometheus_api_project_cluster_path(
+              project,
+              params[:cluster],
+              proxy_path: query_type(metric),
+              query: query_for_metric(metric)
+            )
+          end
+
+          def query_type(metric)
+            metric[:query] ? :query : :query_range
+          end
+
+          def query_for_metric(metric)
+            query = metric[query_type(metric)]
+
+            raise Errors::MissingQueryError.new('Each "metric" must define one of :query or :query_range') unless query
+
+            query
+          end
+
+          def verify_params
+            raise Errors::DashboardProcessingError.new(_('Cluster is required for Stages::ClusterEndpointInserter')) unless params[:cluster]
+            raise Errors::DashboardProcessingError.new(_('Cluster type must be specificed for Stages::ClusterEndpointInserter')) unless params[:cluster_type]
+          end
+        end
+      end
+    end
+  end
+end