Do not enable prometheus metrics when data folder is not present.

+ Set defaults correctly only for when not in production or staging
+ set ENV['prometheus_multiproc_dir'] in config/boot.rb instead of config.ru

Test prometheus metrics unmemoized

1 files changed, 12 insertions, 1 deletions

diff --git a/lib/gitlab/metrics/prometheus.rb b/lib/gitlab/metrics/prometheus.rb
index 60686509332..25421c0a92f 100644
--- a/lib/gitlab/metrics/prometheus.rb
+++ b/lib/gitlab/metrics/prometheus.rb
@@ -5,8 +5,13 @@ module Gitlab
     module Prometheus
       include Gitlab::CurrentSettings
 
+      def metrics_folder_present?
+        ENV.has_key?('prometheus_multiproc_dir') && ::Dir.exist?(ENV['prometheus_multiproc_dir']) &&
+          ::File.writable?(ENV['prometheus_multiproc_dir'])
+      end
+
       def prometheus_metrics_enabled?
-        @prometheus_metrics_enabled ||= current_application_settings[:prometheus_metrics_enabled] || false
+        @prometheus_metrics_enabled ||= prometheus_metrics_enabled_unmemoized
       end
 
       def registry
@@ -36,6 +41,12 @@ module Gitlab
           NullMetric.new
         end
       end
+
+      private
+
+      def prometheus_metrics_enabled_unmemoized
+        metrics_folder_present? && current_application_settings[:prometheus_metrics_enabled] || false
+      end
     end
   end
 end