Log and pass correlation-id between Unicorn, Sidekiq and Gitaly

The Correlation ID is taken or generated from received X-Request-ID.
Then it is being passed to all executed services (sidekiq workers
or gitaly calls).

The Correlation ID is logged in all structured logs as `correlation_id`.

1 files changed, 35 insertions, 0 deletions

diff --git a/lib/gitlab/middleware/correlation_id.rb b/lib/gitlab/middleware/correlation_id.rb
new file mode 100644
index 00000000000..4eafa09183c
--- /dev/null
+++ b/lib/gitlab/middleware/correlation_id.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+# A dumb middleware that steals correlation id
+# and sets it as a global context for the request
+module Gitlab
+  module Middleware
+    class CorrelationId
+      include ActionView::Helpers::TagHelper
+
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        Gitlab::CorrelationId.use_id(correlation_id(env)) do
+          @app.call(env)
+        end
+      end
+
+      private
+
+      def correlation_id(env)
+        if Gitlab.rails5?
+          request(env).request_id
+        else
+          request(env).uuid
+        end
+      end
+
+      def request(env)
+        ActionDispatch::Request.new(env)
+      end
+    end
+  end
+end