Bind to a hosts local interface

I have projects that I'd like to run inside Oniux, which use web interface that binds on localhost. It would be great if I could connect to that interface on http://127.0.0.1:1234 while the rest of the connectivity would stay isolated. I'm not sure about the details of network namespace based isolation used by Oniux, so I'm not sure how to accomplish this, but I thought it might be worth to ask.