retain body for requests (#2182)

Retain request body for requests with application/x-www-form-urlencoded as it is drained when ParseForm

middleware.go

@@ -1,7 +1,10 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
+	"io"
+	"io/ioutil"
 	"net/http"
 	"strconv"
 	"time"
@@ -427,3 +430,20 @@ func handleResponseChain(chain []TykResponseHandler, rw http.ResponseWriter, res
 	}
 	return nil
 }
+
+func parseForm(r *http.Request) {
+	// https://golang.org/pkg/net/http/#Request.ParseForm
+	// ParseForm drains the request body for a request with Content-Type of
+	// application/x-www-form-urlencoded
+	if r.Header.Get("Content-Type") == "application/x-www-form-urlencoded" {
+		var b bytes.Buffer
+		r.Body = ioutil.NopCloser(io.TeeReader(r.Body, &b))
+
+		r.ParseForm()
+
+		r.Body = ioutil.NopCloser(&b)
+		return
+	}
+
+	r.ParseForm()
+}

mw_context_vars.go

@@ -23,7 +23,8 @@ func (m *MiddlewareContextVars) EnabledForSpec() bool {
 
 // ProcessRequest will run any checks on the request on the way through the system, return an error to have the chain fail
 func (m *MiddlewareContextVars) ProcessRequest(w http.ResponseWriter, r *http.Request, _ interface{}) (error, int) {
-	r.ParseForm()
+
+	parseForm(r)
 
 	contextDataObject := map[string]interface{}{
 		"request_data": r.Form, // Form params (map[string][]string)

mw_rate_check.go

@@ -1,6 +1,8 @@
 package main
 
-import "net/http"
+import (
+	"net/http"
+)
 
 type RateCheckMW struct {
 	BaseMiddleware

mw_virtual_endpoint.go

@@ -139,7 +139,7 @@ func (d *VirtualEndpoint) ServeHTTPForCache(w http.ResponseWriter, r *http.Reque
 
 	// We need to copy the body _back_ for the decode
 	r.Body = ioutil.NopCloser(bytes.NewReader(originalBody))
-	r.ParseForm()
+	parseForm(r)
 	requestData.Params = r.Form
 
 	requestAsJson, err := json.Marshal(requestData)