From 0520b4cd249a6b5f215d66a252f398be58f0f1b6 Mon Sep 17 00:00:00 2001
From: Ryan Bourgeois <bluedragonx@gmail.com>
Date: Mon, 1 Jun 2015 11:45:23 -0700
Subject: [PATCH] proxy: Reuse a bytes buffer as proxy request body.

The call to transport.RoundTrip closes the request body regardless of
the value of request.Closed. This causes subsequent calls to RoundTrip
using the same request body to fail.

Fixes #2895
---
 proxy/reverse.go | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/proxy/reverse.go b/proxy/reverse.go
index ee0b9cbcd..0db5bd111 100644
--- a/proxy/reverse.go
+++ b/proxy/reverse.go
@@ -15,8 +15,10 @@
 package proxy
 
 import (
+	"bytes"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"log"
 	"net"
 	"net/http"
@@ -55,6 +57,21 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	proxyreq := new(http.Request)
 	*proxyreq = *clientreq
 
+	var (
+		proxybody []byte
+		err       error
+	)
+
+	if clientreq.Body != nil {
+		proxybody, err = ioutil.ReadAll(clientreq.Body)
+		if err != nil {
+			msg := fmt.Sprintf("proxy: failed to read request body: %v", err)
+			e := httptypes.NewHTTPError(http.StatusInternalServerError, msg)
+			e.WriteTo(rw)
+			return
+		}
+	}
+
 	// deep-copy the headers, as these will be modified below
 	proxyreq.Header = make(http.Header)
 	copyHeader(proxyreq.Header, clientreq.Header)
@@ -93,9 +110,11 @@ func (p *reverseProxy) ServeHTTP(rw http.ResponseWriter, clientreq *http.Request
 	}
 
 	var res *http.Response
-	var err error
 
 	for _, ep := range endpoints {
+		if proxybody != nil {
+			proxyreq.Body = ioutil.NopCloser(bytes.NewBuffer(proxybody))
+		}
 		redirectRequest(proxyreq, ep.URL)
 
 		res, err = p.transport.RoundTrip(proxyreq)