Migrate correlation and tracing code to LabKitan-use-labkit

This change is a fairly straightforward refactor to extract the tracing
and correlation-id code from the gitlab rails codebase into the new
LabKit-Ruby project.

The corresponding import into LabKit-Ruby was in
https://gitlab.com/gitlab-org/labkit-ruby/merge_requests/1

The code itself remains very similar for now.

Extracting it allows us to reuse it in other projects, such as
Gitaly-Ruby. This will give us the advantages of correlation-ids and
distributed tracing in that project too.

1 files changed, 3 insertions, 6 deletions

diff --git a/Gemfile b/Gemfile
index 50099f5a3b1..eaaf8125009 100644
--- a/Gemfile
+++ b/Gemfile
@@ -274,6 +274,9 @@ gem 'sentry-raven', '~> 2.7'
 
 gem 'premailer-rails', '~> 1.9.7'
 
+# LabKit: Tracing and Correlation
+gem 'gitlab-labkit', '~> 0.1.2'
+
 # I18n
 gem 'ruby_parser', '~> 3.8', require: false
 gem 'rails-i18n', '~> 5.1'
@@ -301,12 +304,6 @@ group :metrics do
   gem 'raindrops', '~> 0.18'
 end
 
-group :tracing do
-  # OpenTracing
-  gem 'opentracing', '~> 0.4.3'
-  gem 'jaeger-client', '~> 0.10.0'
-end
-
 group :development do
   gem 'foreman', '~> 0.84.0'
   gem 'brakeman', '~> 4.2', require: false