Fix a NoMethodError in Geo::MetricsUpdateService

app/services/geo/metrics_update_service.rb

@@ -23,7 +23,7 @@ module Geo
     end
 
     def fetch_geo_node_metrics(node)
-      return unless node.enabled?
+      return unless node&.enabled?
       return unless Gitlab::Geo.primary? || Gitlab::Metrics.prometheus_metrics_enabled?
 
       status = node_status(node)

changelogs/unreleased-ee/fix-nil-method-error-metrics-update-service.yml

+---
+title: Fix a bug in the Geo metrics update service
+merge_request: 3623
+author:
+type: fixed

spec/services/geo/metrics_update_service_spec.rb

@@ -3,6 +3,10 @@ require 'spec_helper'
 describe Geo::MetricsUpdateService, :geo do
   include ::EE::GeoHelpers
 
+  set(:primary) { create(:geo_node, :primary) }
+  set(:secondary) { create(:geo_node) }
+  set(:another_secondary) { create(:geo_node) }
+
   subject { described_class.new }
 
   let(:event_date) { Time.now.utc }
@@ -38,11 +42,19 @@ describe Geo::MetricsUpdateService, :geo do
       allow(Geo::NodeStatusFetchService).to receive(:get).and_return(request)
     end
 
-    context 'when node is the primary' do
-      set(:primary) { create(:geo_node, :primary) }
-      set(:secondary) { create(:geo_node) }
-      set(:another_secondary) { create(:geo_node) }
+    context 'when current node is nil' do
+      before do
+        stub_current_geo_node(nil)
+      end
+
+      it 'skips fetching the status' do
+        expect(Geo::NodeStatusFetchService).to receive(:get).never
 
+        subject.execute
+      end
+    end
+
+    context 'when node is the primary' do
       before do
         stub_current_geo_node(primary)
       end
@@ -75,8 +87,6 @@ describe Geo::MetricsUpdateService, :geo do
     end
 
     context 'when node is a secondary' do
-      set(:secondary) { create(:geo_node) }
-
       subject { described_class.new }
 
       before do