Send 'Retry-After' to comply with RFC6585.

vendor/github.com/vulcand/oxy/forward/headers.go

@@ -1,5 +1,6 @@
 package forward
 
+// Headers
 const (
 	XForwardedProto        = "X-Forwarded-Proto"
 	XForwardedFor          = "X-Forwarded-For"
@@ -22,7 +23,7 @@ const (
 	SecWebsocketAccept     = "Sec-Websocket-Accept"
 )
 
-// Hop-by-hop headers. These are removed when sent to the backend.
+// HopHeaders Hop-by-hop headers. These are removed when sent to the backend.
 // http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html
 // Copied from reverseproxy.go, too bad
 var HopHeaders = []string{
@@ -36,6 +37,7 @@ var HopHeaders = []string{
 	Upgrade,
 }
 
+// WebsocketDialHeaders Websocket dial headers
 var WebsocketDialHeaders = []string{
 	Upgrade,
 	Connection,
@@ -45,6 +47,7 @@ var WebsocketDialHeaders = []string{
 	SecWebsocketAccept,
 }
 
+// WebsocketUpgradeHeaders Websocket upgrade headers
 var WebsocketUpgradeHeaders = []string{
 	Upgrade,
 	Connection,
@@ -52,6 +55,7 @@ var WebsocketUpgradeHeaders = []string{
 	SecWebsocketExtensions,
 }
 
+// XHeaders X-* headers
 var XHeaders = []string{
 	XForwardedProto,
 	XForwardedFor,