Upgrading server dependancies (#4566)

vendor/github.com/gorilla/handlers/proxy_headers.go

@@ -8,9 +8,11 @@ import (
 
 var (
 	// De-facto standard header keys.
-	xForwardedFor   = http.CanonicalHeaderKey("X-Forwarded-For")
-	xRealIP         = http.CanonicalHeaderKey("X-Real-IP")
-	xForwardedProto = http.CanonicalHeaderKey("X-Forwarded-Scheme")
+	xForwardedFor    = http.CanonicalHeaderKey("X-Forwarded-For")
+	xForwardedHost   = http.CanonicalHeaderKey("X-Forwarded-Host")
+	xForwardedProto  = http.CanonicalHeaderKey("X-Forwarded-Proto")
+	xForwardedScheme = http.CanonicalHeaderKey("X-Forwarded-Scheme")
+	xRealIP          = http.CanonicalHeaderKey("X-Real-IP")
 )
 
 var (
@@ -28,9 +30,9 @@ var (
 
 // ProxyHeaders inspects common reverse proxy headers and sets the corresponding
 // fields in the HTTP request struct. These are X-Forwarded-For and X-Real-IP
-// for the remote (client) IP address, X-Forwarded-Proto for the scheme
-// (http|https) and the RFC7239 Forwarded header, which may include both client
-// IPs and schemes.
+// for the remote (client) IP address, X-Forwarded-Proto or X-Forwarded-Scheme
+// for the scheme (http|https) and the RFC7239 Forwarded header, which may
+// include both client IPs and schemes.
 //
 // NOTE: This middleware should only be used when behind a reverse
 // proxy like nginx, HAProxy or Apache. Reverse proxies that don't (or are
@@ -49,7 +51,10 @@ func ProxyHeaders(h http.Handler) http.Handler {
 		if scheme := getScheme(r); scheme != "" {
 			r.URL.Scheme = scheme
 		}
-
+		// Set the host with the value passed by the proxy
+		if r.Header.Get(xForwardedHost) != "" {
+			r.Host = r.Header.Get(xForwardedHost)
+		}
 		// Call the next handler in the chain.
 		h.ServeHTTP(w, r)
 	}
@@ -99,7 +104,9 @@ func getScheme(r *http.Request) string {
 	// Retrieve the scheme from X-Forwarded-Proto.
 	if proto := r.Header.Get(xForwardedProto); proto != "" {
 		scheme = strings.ToLower(proto)
-	} else if proto := r.Header.Get(forwarded); proto != "" {
+	} else if proto = r.Header.Get(xForwardedScheme); proto != "" {
+		scheme = strings.ToLower(proto)
+	} else if proto = r.Header.Get(forwarded); proto != "" {
 		// match should contain at least two elements if the protocol was
 		// specified in the Forwarded header. The first element will always be
 		// the 'proto=' capture, which we ignore. In the case of multiple proto