Merge branch 'master' into feature/gb/serverless-serving-enable

* master:
  Add prometheus metrics for GitLab API client
  Fix benchmarks
  Freeze tools version
  Add acceptance test for serverless metrics
  Update documentation on using Gorilla ProxyHeaders
  use gorilla/handlers.ProxyHeaders to get the X-Forwarded-* headers and set them in the appropriate http.Request fields
  Apply suggestion to metrics/metrics.go
  Add serverless serving metrics

Conflicts:
	internal/serving/serverless/serverless.go

2 files changed, 9 insertions, 1 deletions

diff --git a/internal/serving/serverless/serverless.go b/internal/serving/serverless/serverless.go
index 3c360054..bec6db16 100644
--- a/internal/serving/serverless/serverless.go
+++ b/internal/serving/serverless/serverless.go
@@ -7,6 +7,7 @@ import (
 	"gitlab.com/gitlab-org/gitlab-pages/internal/httperrors"
 	"gitlab.com/gitlab-org/gitlab-pages/internal/serving"
 	"gitlab.com/gitlab-org/gitlab-pages/internal/source/gitlab/api"
+	"gitlab.com/gitlab-org/gitlab-pages/metrics"
 )
 
 // Serverless is a servering used to proxy requests between a client and
@@ -55,6 +56,8 @@ func New(function Function, cluster Cluster) serving.Serving {
 
 // ServeFileHTTP handle an incoming request and proxies it to Knative cluster
 func (s *Serverless) ServeFileHTTP(h serving.Handler) bool {
+	metrics.ServerlessRequests.Inc()
+
 	s.proxy.ServeHTTP(h.Writer, h.Request)
 
 	return true
diff --git a/internal/serving/serverless/transport.go b/internal/serving/serverless/transport.go
index 5a0f5165..b7fabb13 100644
--- a/internal/serving/serverless/transport.go
+++ b/internal/serving/serverless/transport.go
@@ -5,6 +5,8 @@ import (
 	"net"
 	"net/http"
 	"time"
+
+	"gitlab.com/gitlab-org/gitlab-pages/metrics"
 )
 
 // Transport is a struct that handle the proxy connection round trip to Knative
@@ -39,8 +41,11 @@ func NewTransport(cluster Cluster) *Transport {
 
 // RoundTrip performs a connection to a Knative cluster and returns a response
 func (t *Transport) RoundTrip(request *http.Request) (*http.Response, error) {
+	start := time.Now()
+
 	response, err := t.transport.RoundTrip(request)
 
-	// TODO add prometheus metrics for round trip timing
+	metrics.ServerlessLatency.Observe(time.Since(start).Seconds())
+
 	return response, err
 }