1 files changed, 45 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/connection_rack_middleware.rb b/lib/gitlab/metrics/connection_rack_middleware.rb
new file mode 100644
index 00000000000..b3da360be8f
--- /dev/null
+++ b/lib/gitlab/metrics/connection_rack_middleware.rb
@@ -0,0 +1,45 @@
+module Gitlab
+  module Metrics
+    class ConnectionRackMiddleware
+      def initialize(app)
+        @app = app
+      end
+
+      def self.rack_request_count
+        @rack_request_count ||= Gitlab::Metrics.counter(:rack_request, 'Rack request count')
+      end
+
+      def self.rack_response_count
+        @rack_response_count ||= Gitlab::Metrics.counter(:rack_response, 'Rack response count')
+      end
+
+      def self.rack_uncaught_errors_count
+        @rack_uncaught_errors_count ||= Gitlab::Metrics.counter(:rack_uncaught_errors, 'Rack connections handling uncaught errors count')
+      end
+
+      def self.rack_execution_time
+        @rack_execution_time ||= Gitlab::Metrics.histogram(:rack_execution_time, 'Rack connection handling execution time',
+                                                           {}, [0.05, 0.1, 0.25, 0.5, 0.7, 1, 1.5, 2, 2.5, 3, 5, 7, 10])
+      end
+
+      def call(env)
+        method = env['REQUEST_METHOD'].downcase
+        started = Time.now.to_f
+        begin
+          ConnectionRackMiddleware.rack_request_count.increment(method: method)
+
+          status, headers, body = @app.call(env)
+
+          ConnectionRackMiddleware.rack_response_count.increment(method: method, status: status)
+          [status, headers, body]
+        rescue
+          ConnectionRackMiddleware.rack_uncaught_errors_count.increment
+          raise
+        ensure
+          elapsed = Time.now.to_f - started
+          ConnectionRackMiddleware.rack_execution_time.observe({}, elapsed)
+        end
+      end
+    end
+  end
+end