Add reverse proxy

[fritterhoff]

To reduce the huge amount of required ports add a reverse proxy in front of the web applications.

[fritterhoff]

I had a quick look on that topic the last days. From my point of view, the best solution would be treafik in front of all services and select the individual service on the path. (e.g. localhost/extractor get's bound to the extractor service)

The first hacky tests didn't work fine because the flask apps don't recognize that they're behind the proxy and e.g. try to load the static components from the root (localhost/static instead of localhost/extractor/static). The common approaches for Flask like setting the SCRIPT_NAME env var did not work 😞