Read request body and see if it's not empty then decide whether write it or not

api/agent/protocol/json.go

@@ -37,19 +37,19 @@ func (h *JSONProtocol) DumpJSON(w io.Writer, req *http.Request) error {
 		return err
 	}
 
-	if req.ContentLength != 0 {
-		_, err := io.WriteString(h.in, `"body": `)
-		if err != nil {
-			// this shouldn't happen
-			return err
-		}
 	bb := new(bytes.Buffer)
 	_, err = bb.ReadFrom(req.Body)
 	if err != nil {
 		return err
 	}
-
-		err = stdin.Encode(bb.String())
+	reqData := bb.String()
+	if reqData != "" {
+		_, err := io.WriteString(h.in, `"body": `)
+		if err != nil {
+			// this shouldn't happen
+			return err
+		}
+		err = stdin.Encode(reqData)
 		if err != nil {
 			return err
 		}