Allow configuration of url path

[adrianipopescu]

Is your feature request related to a problem? Please describe.
I'd like to host the app on a subpath rather than a specific subdomain when exposing via a proxy.

Describe the solution you'd like
An env var or config file where I can specify where the app is located

Describe alternatives you've considered
Proxying via subdomain or just exposing the ports, but I'd prefer to only expose the bare minimum of each app

Additional context
Right now it's giving an error since it cannot map the routes.

[tpanajott]

Yhea, that sounds reasonable and would also help with hosting the manager as an HA addon using the ingress method instead.