1 files changed, 41 insertions, 0 deletions
diff --git a/lib/gitlab/metrics/exporter/metrics_middleware.rb b/lib/gitlab/metrics/exporter/metrics_middleware.rb
new file mode 100644
index 00000000000..e17f1c13cf0
--- /dev/null
+++ b/lib/gitlab/metrics/exporter/metrics_middleware.rb
@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Metrics
+    module Exporter
+      class MetricsMiddleware
+        def initialize(app, pid)
+          @app = app
+          default_labels = {
+            pid: pid
+          }
+          @requests_total = Gitlab::Metrics.counter(
+            :exporter_http_requests_total, 'Total number of HTTP requests', default_labels
+          )
+          @request_durations = Gitlab::Metrics.histogram(
+            :exporter_http_request_duration_seconds,
+            'HTTP request duration histogram (seconds)',
+            default_labels,
+            [0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10]
+          )
+        end
+
+        def call(env)
+          start = Gitlab::Metrics::System.monotonic_time
+          @app.call(env).tap do |response|
+            duration = Gitlab::Metrics::System.monotonic_time - start
+
+            labels = {
+              method: env['REQUEST_METHOD'].downcase,
+              path:   env['PATH_INFO'].to_s,
+              code:   response.first.to_s
+            }
+
+            @requests_total.increment(labels)
+            @request_durations.observe(labels, duration)
+          end
+        end
+      end
+    end
+  end
+end