connect to a host service (Rails) from Voodoo

gistfile1.txt

start Rails with the option to listen to any IP, for instance:
bundle exec rails s -b 0.0.0.0

use the https://github.com/gliderlabs/hostlocal tool to create a new "loopback interface":
docker run --rm --privileged --net=host gliderlabs/hostlocal

start Voodoo

inside Voodoo, your host is accessible with the same ports (port 3000 for Rails dev for instance) but the host is now called;
hostlocal.io

so for instance you can connect to Rails inside Voodoo with
wget http://hostlocal.io:3000

So if you are trying to reach that host service from Odoo, for instance if you use the connector_devise connector. you should
set the backend to http://hostlocal.io:3000

CQFD