From 85532d490fc113a9a10f030948d93b5cb090926e Mon Sep 17 00:00:00 2001
From: Pawel Chojnacki <pawel@chojnacki.ws>
Date: Thu, 15 Jun 2017 23:41:47 +0200
Subject: [PATCH] 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
---
 app/views/admin/application_settings/_form.html.haml | 4 ++++
 config.ru                                            | 3 ---
 config/boot.rb                                       | 5 +++++
 lib/gitlab/metrics/prometheus.rb                     | 6 +++++-
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/app/views/admin/application_settings/_form.html.haml b/app/views/admin/application_settings/_form.html.haml
index d552704df88056..d30ab0c0eaab6a 100644
--- a/app/views/admin/application_settings/_form.html.haml
+++ b/app/views/admin/application_settings/_form.html.haml
@@ -310,6 +310,10 @@
           = f.label :prometheus_metrics_enabled do
             = f.check_box :prometheus_metrics_enabled
             Enable Prometheus Metrics
+            - if !Gitlab::Metrics.metrics_folder_present?
+              .help-block
+                %strong.cred WARNING:
+                Environment variable `prometheus_multiproc_dir` does not exist or is not pointing to a valid directory.
 
   %fieldset
     %legend Background Jobs
diff --git a/config.ru b/config.ru
index 89aba462f19619..065ce59932f2ff 100644
--- a/config.ru
+++ b/config.ru
@@ -15,9 +15,6 @@ if defined?(Unicorn)
   end
 end
 
-# set default directory for multiproces metrics gathering
-ENV['prometheus_multiproc_dir'] ||= 'tmp/prometheus_multiproc_dir'
-
 require ::File.expand_path('../config/environment',  __FILE__)
 
 map ENV['RAILS_RELATIVE_URL_ROOT'] || "/" do
diff --git a/config/boot.rb b/config/boot.rb
index 17a7114837028a..7e8de3b6da3e7e 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -5,6 +5,11 @@
 
 require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
 
+# set default directory for multiproces metrics gathering
+unless ENV['RAILS_ENV'] == 'production' || ENV['RAILS_ENV'] == 'staging'
+  ENV['prometheus_multiproc_dir'] ||= 'tmp/prometheus_multiproc_dir'
+end
+
 # Default Bootsnap configuration from https://github.com/Shopify/bootsnap#usage
 require 'bootsnap'
 Bootsnap.setup(
diff --git a/lib/gitlab/metrics/prometheus.rb b/lib/gitlab/metrics/prometheus.rb
index 606865093324fe..c7a2ae03508a59 100644
--- a/lib/gitlab/metrics/prometheus.rb
+++ b/lib/gitlab/metrics/prometheus.rb
@@ -5,8 +5,12 @@ module Metrics
     module Prometheus
       include Gitlab::CurrentSettings
 
+      def metrics_folder_present?
+        ENV.has_key?('prometheus_multiproc_dir') && ::Dir.exist?(ENV['prometheus_multiproc_dir'])
+      end
+
       def prometheus_metrics_enabled?
-        @prometheus_metrics_enabled ||= current_application_settings[:prometheus_metrics_enabled] || false
+        @prometheus_metrics_enabled ||= metrics_folder_present? || current_application_settings[:prometheus_metrics_enabled] || false
       end
 
       def registry
-- 
GitLab