Prometheus settings

app/controllers/admin/application_settings_controller.rb

@@ -149,6 +149,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       :version_check_enabled,
       :terminal_max_session_time,
       :polling_interval_multiplier,
+      :prometheus_metrics_enabled,
       :usage_ping_enabled,
 
       disabled_oauth_sign_in_sources: [],

db/schema.rb

@@ -123,6 +123,7 @@ ActiveRecord::Schema.define(version: 20170525174156) do
     t.integer "cached_markdown_version"
     t.boolean "clientside_sentry_enabled", default: false, null: false
     t.string "clientside_sentry_dsn"
+    t.boolean "prometheus_metrics_enabled", default: false, null: false
   end
 
   create_table "audit_events", force: :cascade do |t|

lib/api/settings.rb

@@ -110,6 +110,7 @@ module API
       optional :default_artifacts_expire_in, type: String, desc: "Set the default expiration time for each job's artifacts"
       optional :max_pages_size, type: Integer, desc: 'Maximum size of pages in MB'
       optional :container_registry_token_expire_delay, type: Integer, desc: 'Authorization token duration (minutes)'
+      optional :prometheus_metrics_enabled, type: Boolean, desc: 'Enable Prometheus metrics'
       optional :metrics_enabled, type: Boolean, desc: 'Enable the InfluxDB metrics'
       given metrics_enabled: ->(val) { val } do
         requires :metrics_host, type: String, desc: 'The InfluxDB host'

lib/gitlab/metrics.rb

@@ -10,15 +10,15 @@ module Gitlab
 
     def self.settings
       @settings ||= {
-        enabled:               current_application_settings[:metrics_enabled],
-        prometheus_metrics_enabled: true,
-        pool_size:             current_application_settings[:metrics_pool_size],
-        timeout:               current_application_settings[:metrics_timeout],
-        method_call_threshold: current_application_settings[:metrics_method_call_threshold],
-        host:                  current_application_settings[:metrics_host],
-        port:                  current_application_settings[:metrics_port],
-        sample_interval:       current_application_settings[:metrics_sample_interval] || 15,
-        packet_size:           current_application_settings[:metrics_packet_size] || 1
+        enabled:                    current_application_settings[:metrics_enabled],
+        prometheus_metrics_enabled: current_application_settings[:prometheus_metrics_enabled],
+        pool_size:                  current_application_settings[:metrics_pool_size],
+        timeout:                    current_application_settings[:metrics_timeout],
+        method_call_threshold:      current_application_settings[:metrics_method_call_threshold],
+        host:                       current_application_settings[:metrics_host],
+        port:                       current_application_settings[:metrics_port],
+        sample_interval:            current_application_settings[:metrics_sample_interval] || 15,
+        packet_size:                current_application_settings[:metrics_packet_size] || 1
       }
     end
 
@@ -31,7 +31,7 @@ module Gitlab
     end
 
     def self.enabled?
-      influx_metrics_enabled? || prometheus_metrics_enabled? || false
+      influx_metrics_enabled? || prometheus_metrics_enabled?
     end
 
     def self.mri?