SplitHTTP server: Add noSSEHeader

#3603 (comment)

infra/conf/transport_internet.go

@@ -232,6 +232,7 @@ type SplitHTTPConfig struct {
 	MaxConcurrentUploads Int32Range        `json:"maxConcurrentUploads"`
 	MaxUploadSize        Int32Range        `json:"maxUploadSize"`
 	MinUploadIntervalMs  Int32Range        `json:"minUploadIntervalMs"`
+	NoSSEHeader          bool              `json:"noSSEHeader"`
 }
 
 // Build implements Buildable.
@@ -260,6 +261,7 @@ func (c *SplitHTTPConfig) Build() (proto.Message, error) {
 			From: c.MinUploadIntervalMs.From,
 			To:   c.MinUploadIntervalMs.To,
 		},
+		NoSSEHeader: c.NoSSEHeader,
 	}
 	return config, nil
 }

transport/internet/splithttp/config.proto

@@ -13,6 +13,7 @@ message Config {
   RandRangeConfig maxConcurrentUploads = 4;
   RandRangeConfig maxUploadSize = 5;
   RandRangeConfig minUploadIntervalMs = 6;
+  bool noSSEHeader = 7;
 }
 
 message RandRangeConfig {

transport/internet/splithttp/hub.go

@@ -26,6 +26,7 @@ import (
 )
 
 type requestHandler struct {
+	config    *Config
 	host      string
 	path      string
 	ln        *Listener
@@ -182,8 +183,10 @@ func (h *requestHandler) ServeHTTP(writer http.ResponseWriter, request *http.Req
 
 		// magic header instructs nginx + apache to not buffer response body
 		writer.Header().Set("X-Accel-Buffering", "no")
-		// magic header to make the HTTP middle box consider this as SSE to disable buffer
-		writer.Header().Set("Content-Type", "text/event-stream")
+		if !h.config.NoSSEHeader {
+			// magic header to make the HTTP middle box consider this as SSE to disable buffer
+			writer.Header().Set("Content-Type", "text/event-stream")
+		}
 
 		writer.WriteHeader(http.StatusOK)
 		// send a chunk immediately to enable CDN streaming.
@@ -267,6 +270,7 @@ func ListenSH(ctx context.Context, address net.Address, port net.Port, streamSet
 	var err error
 	var localAddr = gonet.TCPAddr{}
 	handler := &requestHandler{
+		config:    shSettings,
 		host:      shSettings.Host,
 		path:      shSettings.GetNormalizedPath("", false),
 		ln:        l,