Merge branch 'sh-move-sidekiq-exporter-logs' into 'master'

Move Sidekiq exporter logs to log/sidekiq_exporter.log

See merge request gitlab-org/gitlab-ce!18127

4 files changed, 25 insertions, 2 deletions

diff --git a/changelogs/unreleased/sh-move-sidekiq-exporter-logs.yml b/changelogs/unreleased/sh-move-sidekiq-exporter-logs.yml
new file mode 100644
index 00000000000..1990f4f6124
--- /dev/null
+++ b/changelogs/unreleased/sh-move-sidekiq-exporter-logs.yml
@@ -0,0 +1,5 @@
+---
+title: Move Sidekiq exporter logs to log/sidekiq_exporter.log
+merge_request:
+author:
+type: other
diff --git a/doc/administration/logs.md b/doc/administration/logs.md
index 00a2f3d01b8..cd107a5b39c 100644
--- a/doc/administration/logs.md
+++ b/doc/administration/logs.md
@@ -206,4 +206,12 @@ is populated whenever `gitlab-ctl reconfigure` is run manually or as part of an
 Reconfigure logs files are named according to the UNIX timestamp of when the reconfigure
 was initiated, such as `1509705644.log`
 
+## `sidekiq_exporter.log`
+
+If Prometheus metrics and the Sidekiq Exporter are both enabled, Sidekiq will
+start a Web server and listen to the defined port (default: 3807). Access logs
+will be generated in `/var/log/gitlab/gitlab-rails/sidekiq_exporter.log` for
+Omnibus GitLab packages or in `/home/git/gitlab/log/sidekiq_exporter.log` for
+installations from source.
+
 [repocheck]: repository_checks.md
diff --git a/lib/gitlab/metrics/sidekiq_metrics_exporter.rb b/lib/gitlab/metrics/sidekiq_metrics_exporter.rb
index db8bdde74b2..47b4af5d649 100644
--- a/lib/gitlab/metrics/sidekiq_metrics_exporter.rb
+++ b/lib/gitlab/metrics/sidekiq_metrics_exporter.rb
@@ -4,6 +4,8 @@ require 'prometheus/client/rack/exporter'
 module Gitlab
   module Metrics
     class SidekiqMetricsExporter < Daemon
+      LOG_FILENAME = File.join(Rails.root, 'log', 'sidekiq_exporter.log')
+
       def enabled?
         Gitlab::Metrics.metrics_folder_present? && settings.enabled
       end
@@ -17,7 +19,13 @@ module Gitlab
       attr_reader :server
 
       def start_working
-        @server = ::WEBrick::HTTPServer.new(Port: settings.port, BindAddress: settings.address)
+        logger = WEBrick::Log.new(LOG_FILENAME)
+        access_log = [
+          [logger, WEBrick::AccessLog::COMBINED_LOG_FORMAT]
+        ]
+
+        @server = ::WEBrick::HTTPServer.new(Port: settings.port, BindAddress: settings.address,
+                                            Logger: logger, AccessLog: access_log)
         server.mount "/", Rack::Handler::WEBrick, rack_app
         server.start
       end
diff --git a/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb b/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb
index 6721e02fb85..61eb059a731 100644
--- a/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb
+++ b/spec/lib/gitlab/metrics/sidekiq_metrics_exporter_spec.rb
@@ -38,7 +38,9 @@ describe Gitlab::Metrics::SidekiqMetricsExporter do
 
             expect(::WEBrick::HTTPServer).to have_received(:new).with(
               Port: port,
-              BindAddress: address
+              BindAddress: address,
+              Logger: anything,
+              AccessLog: anything
             )
           end
         end