Extract health check in its own middleware

This way we short-circuit health check requests and avoid doing domain
lookup for them. We also do not report them in exported Prometheus
metrics and this way avoid trigger alerts during deploys.

Related to:

* https://gitlab.com/gitlab-org/gitlab-pages/issues/350
* https://gitlab.com/gitlab-com/gl-infra/production/issues/1681

1 files changed, 17 insertions, 4 deletions

diff --git a/internal/logging/logging.go b/internal/logging/logging.go
index 28c43c2e..4ba86985 100644
--- a/internal/logging/logging.go
+++ b/internal/logging/logging.go
@@ -65,20 +65,33 @@ func getExtraLogFields(r *http.Request) log.Fields {
 	}
 }
 
-// AccessLogger configures the GitLab pages HTTP access logger middleware
-func AccessLogger(handler http.Handler, format string) (http.Handler, error) {
-
+// BasicAccessLogger configures the GitLab pages basic HTTP access logger middleware
+func BasicAccessLogger(handler http.Handler, format string, extraFields log.ExtraFieldsGeneratorFunc) (http.Handler, error) {
 	accessLogger, err := getAccessLogger(format)
 	if err != nil {
 		return nil, err
 	}
 
+	if extraFields == nil {
+		extraFields = func(r *http.Request) log.Fields {
+			return log.Fields{
+				"pages_https": request.IsHTTPS(r),
+				"pages_host":  r.Host,
+			}
+		}
+	}
+
 	return log.AccessLogger(handler,
-		log.WithExtraFields(getExtraLogFields),
+		log.WithExtraFields(extraFields),
 		log.WithAccessLogger(accessLogger),
 	), nil
 }
 
+// AccessLogger configures the GitLab pages HTTP access logger middleware with extra log fields
+func AccessLogger(handler http.Handler, format string) (http.Handler, error) {
+	return BasicAccessLogger(handler, format, getExtraLogFields)
+}
+
 // LogRequest will inject request host and path to the logged messages
 func LogRequest(r *http.Request) *logrus.Entry {
 	return log.WithFields(log.Fields{