Remove Golang reverseproxy and use http Client

Signed-off-by: Alex Ellis <alexellis2@gmail.com>

gateway/handlers/forwarding_proxy.go

@@ -1,9 +1,9 @@
 package handlers
 
 import (
+	"io"
 	"log"
 	"net/http"
-	"net/http/httputil"
 	"strconv"
 	"strings"
 	"time"
@@ -14,36 +14,66 @@ import (
 )
 
 // MakeForwardingProxyHandler create a handler which forwards HTTP requests
-func MakeForwardingProxyHandler(proxy *httputil.ReverseProxy, metrics *metrics.MetricOptions) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		uri := r.URL.String()
+func MakeForwardingProxyHandler(proxy *types.HttpClientReverseProxy, metrics *metrics.MetricOptions) http.HandlerFunc {
+	baseURL := proxy.BaseURL.String()
+	if strings.HasSuffix(baseURL, "/") {
+		baseURL = baseURL[0 : len(baseURL)-1]
+	}
 
-		log.Printf("> Forwarding [%s] to %s", r.Method, r.URL.String())
+	return func(w http.ResponseWriter, r *http.Request) {
+
+		requestURL := r.URL.String()
+
+		log.Printf("> Forwarding [%s] to %s", r.Method, requestURL)
 		start := time.Now()
 
-		writeAdapter := types.NewWriteAdapter(w)
-		proxy.ServeHTTP(writeAdapter, r)
+		upstreamReq, _ := http.NewRequest(r.Method, baseURL+requestURL, nil)
+
+		upstreamReq.Header["X-Forwarded-For"] = []string{r.RequestURI}
+
+		if r.Body != nil {
+			defer r.Body.Close()
+			upstreamReq.Body = r.Body
+
+		}
+
+		res, resErr := proxy.Client.Do(upstreamReq)
+		if resErr != nil {
+			log.Printf("upstream client error: %s\n", resErr)
+			return
+		}
+
+		if res.Body != nil {
+			defer res.Body.Close()
+		}
+
+		for k, v := range res.Header {
+			w.Header()[k] = v
+		}
+
+		io.CopyBuffer(w, res.Body, nil)
 
 		seconds := time.Since(start).Seconds()
 		log.Printf("< [%s] - %d took %f seconds\n", r.URL.String(),
-			writeAdapter.GetHeaderCode(), seconds)
+			res.StatusCode, seconds)
 
 		forward := "/function/"
-		if startsWith(uri, forward) {
+		if startsWith(requestURL, forward) {
 			// log.Printf("function=%s", uri[len(forward):])
 
-			service := uri[len(forward):]
+			service := requestURL[len(forward):]
 
 			metrics.GatewayFunctionsHistogram.
 				WithLabelValues(service).
 				Observe(seconds)
 
-			code := strconv.Itoa(writeAdapter.GetHeaderCode())
+			code := strconv.Itoa(res.StatusCode)
 
 			metrics.GatewayFunctionInvocation.
 				With(prometheus.Labels{"function_name": service, "code": code}).
 				Inc()
 		}
+
 	}
 }