Original function name in callback meta-data

Adds original function name in callback meta-data `X-Function-Name`

Resolves #82

Signed-off-by: Edward Wilde <ewilde@gmail.com>

Author: ewilde

main.go

@@ -111,7 +111,8 @@ func main() {
 					functionResult,
 					req.CallbackURL.String(),
 					xCallID,
-					status)
+					status,
+					req.Function)
 
 				if resultErr != nil {
 					log.Printf("Posted callback to: %s - status %d, error: %s\n", req.CallbackURL.String(), http.StatusServiceUnavailable, resultErr.Error())
@@ -160,7 +161,8 @@ func main() {
 				functionResult,
 				req.CallbackURL.String(),
 				xCallID,
-				res.StatusCode)
+				res.StatusCode,
+				req.Function)
 
 			if resultErr != nil {
 				log.Printf("Error posting to callback-url: %s\n", resultErr)
@@ -252,7 +254,8 @@ func makeClient() http.Client {
 	return proxyClient
 }
 
-func postResult(client *http.Client, functionRes *http.Response, result []byte, callbackURL string, xCallID string, statusCode int) (int, error) {
+func postResult(client *http.Client, functionRes *http.Response, result []byte, callbackURL string, xCallID string,
+	statusCode int, functionName string) (int, error) {
 	var reader io.Reader
 
 	if result != nil {
@@ -270,6 +273,7 @@ func postResult(client *http.Client, functionRes *http.Response, result []byte,
 	}
 
 	request.Header.Set("X-Function-Status", fmt.Sprintf("%d", statusCode))
+	request.Header.Set("X-Function-Name", functionName)
 
 	if len(xCallID) > 0 {
 		request.Header.Set("X-Call-Id", xCallID)