The official docker image drupal:8.3.5-apache needs a few updates to work correctly with a reverse proxy or load balancer in a bridged network.  The main issue is REMOTE_ADDR will always be the docker gateway IP and REQUEST_SCHEME will be http when seen from inside the Apache docker container on port 80.

Option 1: Application level configuration (Drupal example)

Most apps allow configuring the public URL and/or reverse proxy settings.