fix(golang-filter): fix bug of stop and buffer in decode data (#2754)

pkg/ingress/kube/configmap/mcp_server.go

@@ -509,6 +509,11 @@ func (m *McpServerController) constructMcpSessionStruct(mcp *McpServer) string {
 }
 
 func (m *McpServerController) constructMcpServerStruct(mcp *McpServer) string {
+	// if no servers, return empty string
+	if mcp == nil || len(mcp.Servers) == 0 {
+		return ""
+	}
+
 	// Build servers configuration
 	servers := "[]"
 	if len(mcp.Servers) > 0 {

plugins/golang-filter/mcp-server/filter.go

@@ -57,12 +57,12 @@ func (f *filter) DecodeHeaders(header api.RequestHeaderMap, endStream bool) api.
 }
 
 func (f *filter) DecodeData(buffer api.BufferInstance, endStream bool) api.StatusType {
-	if !endStream {
-		return api.StopAndBuffer
-	}
 	if f.message {
 		for _, server := range f.config.servers {
 			if f.path == server.BaseServer.GetMessageEndpoint() {
+				if !endStream {
+					return api.StopAndBuffer
+				}
 				// Create a response recorder to capture the response
 				recorder := httptest.NewRecorder()
 				// Call the handleMessage method of SSEServer with complete body