Drop using explicit container names Compose will generate names for the containers and containers can connect each other on the network via the service names. This avoids the unnecessary extra "name space" and prepares the application for usage with different project names.

#!/bin/sh
export LC_ALL="de_DE.UTF-8"
export NLS_LANG=".AL32UTF8"
export MS_MAPFILE=/opt/d4e/bin/artifacts-data/mapserver/rivers.map
/opt/mapserver/mapserv