1 files changed, 16 insertions, 6 deletions

diff --git a/app.go b/app.go
index 7c927dfe..f64421a4 100644
--- a/app.go
+++ b/app.go
@@ -61,7 +61,7 @@ func (a *theApp) ServeTLS(ch *tls.ClientHelloInfo) (*tls.Certificate, error) {
 		return nil, nil
 	}
 
-	if domain := a.domain(ch.ServerName); domain != nil {
+	if domain, _ := a.domain(ch.ServerName); domain != nil {
 		tls, _ := domain.EnsureCertificate()
 		return tls, nil
 	}
@@ -86,16 +86,18 @@ func (a *theApp) redirectToHTTPS(w http.ResponseWriter, r *http.Request, statusC
 	http.Redirect(w, r, u.String(), statusCode)
 }
 
-func (a *theApp) getHostAndDomain(r *http.Request) (host string, domain *domain.Domain) {
+func (a *theApp) getHostAndDomain(r *http.Request) (string, *domain.Domain, error) {
 	host, _, err := net.SplitHostPort(r.Host)
 	if err != nil {
 		host = r.Host
 	}
 
-	return host, a.domain(host)
+	domain, err := a.domain(host)
+
+	return host, domain, err
 }
 
-func (a *theApp) domain(host string) *domain.Domain {
+func (a *theApp) domain(host string) (*domain.Domain, error) {
 	return a.domains.GetDomain(host)
 }
 
@@ -163,7 +165,15 @@ func (a *theApp) tryAuxiliaryHandlers(w http.ResponseWriter, r *http.Request, ht
 // downstream middlewares to use
 func (a *theApp) routingMiddleware(handler http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		host, domain := a.getHostAndDomain(r)
+		// if we could not retrieve a domain from domains source we break the
+		// middleware chain and simply respond with 502 after logging this
+		host, domain, err := a.getHostAndDomain(r)
+		if err != nil {
+			log.WithError(err).Error("could not fetch domain information from a source")
+
+			httperrors.Serve502(w)
+			return
+		}
 
 		r = request.WithHostAndDomain(r, host, domain)
 
@@ -289,7 +299,7 @@ func (a *theApp) proxyInitialMiddleware(handler http.Handler) http.Handler {
 }
 
 func (a *theApp) buildHandlerPipeline() (http.Handler, error) {
-	// Handlers should be applied in reverse order
+	// Handlers should be applied in a reverse order
 	handler := a.serveFileOrNotFoundHandler()
 	if !a.DisableCrossOriginRequests {
 		handler = corsHandler.Handler(handler)