I am not realy sure why you choose to forward packets using your own commands.
Can you elaborate why publishing the container port to a host port when creating the conatiner using the --publish ${host port}:${container port} (or its short form -p instead of --publish) was not a suitable solution for you?
Also, next time please format your post according this topic: How to format your forum posts
I haven’t looked at your screenshot, as I don’t read when people paste screenshot of texts. I just saw that you used iptables and the bullet points at the bottom of your post. Furthermore, I skipped everything else, because it is hard to read without proper formatting.