I have a golang backend, node frontend. And it worked both on windows and ubuntu without docker. Now I am trying to dockerize everything. I put both backend and frontend in the same docker container. I can establish initial connection but later the backend kept throwing error like this: 
I have exposed port 8000 to 8004, the ws port is 8000 and frontend port is 8004. I have tried both --net=host as well as exposing everything as host ip address 192.168.1.4. Non of them worked.
On the browser side, the websocket client always get 101 response like this:
I think it could be a config problem on docker. But I have no lead right now on how to deal with this. The browser tested is Chrome 55 on windows 10. Docker, golang and node are of the latest. The host machine is on Ubuntu 16.10 as well as container os.
