Defend against dashboard errors, rework sequence

1 files changed, 20 insertions, 0 deletions

diff --git a/lib/gitlab/metrics_dashboard/stages/base_stage.rb b/lib/gitlab/metrics_dashboard/stages/base_stage.rb
index bdbf0c196cc..df49126a07b 100644
--- a/lib/gitlab/metrics_dashboard/stages/base_stage.rb
+++ b/lib/gitlab/metrics_dashboard/stages/base_stage.rb
@@ -4,6 +4,8 @@ module Gitlab
   module MetricsDashboard
     module Stages
       class BaseStage
+        DashboardLayoutError = Class.new(StandardError)
+
         DEFAULT_PANEL_TYPE = 'area-chart'
 
         attr_reader :project, :environment
@@ -23,9 +25,27 @@ module Gitlab
 
         protected
 
+        def missing_panel_groups!
+          raise DashboardLayoutError.new('Top-level key :panel_groups must be an array')
+        end
+
+        def missing_panels!
+          raise DashboardLayoutError.new('Each "panel_group" must define an array :panels')
+        end
+
+        def missing_metrics!
+          raise DashboardLayoutError.new('Each "panel" must define an array :metrics')
+        end
+
         def for_metrics(dashboard)
+          missing_panel_groups! unless dashboard[:panel_groups].is_a?(Array)
+
           dashboard[:panel_groups].each do |panel_group|
+            missing_panels! unless panel_group[:panels].is_a?(Array)
+
             panel_group[:panels].each do |panel|
+              missing_metrics! unless panel[:metrics].is_a?(Array)
+
               panel[:metrics].each do |metric|
                 yield metric
               end