Why would you use Docker at all? Just run the application behind a reverse proxy. Docker doesn't get you anything except an extra management headache and an abstraction that happily punches holes in your firewall.
App A requires a version 2 of whatever which conflicts with version 3 of whatever required by app B, and uses same port as app C and doesn’t like the smell of app D. Meanwhile app Z has to be compiled from source with a specific version of python and only installs on Tuesdays, buts it’s Wednesday if mercury is retrograde
