From 1a9f7002870884779b88e534bc76b2245a57c72d Mon Sep 17 00:00:00 2001
From: Ruben Callewaert <rubencallewaertdev@gmail.com>
Date: Sun, 3 Apr 2016 17:48:53 +0200
Subject: [PATCH] Allow mixed case Upgrade headers

Caddy expects websocket to be completely lowercase.
Some applications send websocket upgrade headers like the following:
`Upgrade: WebSocket`

This change allows all variations of websocket.
---
 middleware/proxy/reverseproxy.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/middleware/proxy/reverseproxy.go b/middleware/proxy/reverseproxy.go
index 7e8815d2e..384ea6cde 100644
--- a/middleware/proxy/reverseproxy.go
+++ b/middleware/proxy/reverseproxy.go
@@ -207,7 +207,7 @@ func (p *ReverseProxy) ServeHTTP(rw http.ResponseWriter, req *http.Request, extr
 		return err
 	}
 
-	if res.StatusCode == http.StatusSwitchingProtocols && res.Header.Get("Upgrade") == "websocket" {
+	if res.StatusCode == http.StatusSwitchingProtocols && strings.ToLower(res.Header.Get("Upgrade")) == "websocket" {
 		res.Body.Close()
 		hj, ok := rw.(http.Hijacker)
 		if !ok {