Access to an application running in a Docker container that runs inside emulated CoreOS in Ubuntu

Question

My problem: I run an application called Cloud9 inside the container, this application runs by default on localhost: 3131, but it is mutable. This Docker Container runs on VMware CoreOS, and VMware CoreOS runs on Ubuntu 14.04 through VirtualBox.

What I need: from the Ubuntu browser, you can access the Cloud9 application running inside Docker.

I tried several things to work on the Docker network (Pipeworks, Docker0 settings, VirtualBox settings, etc.), but I was completely stuck,

How can I access the application through all these layers: Ubuntu> CoreOS> Docker> Cloud9?

Thank you very much.