Build
docker build -t dockersample:latest .
Expose internal port 80 to outer 80, mount D:\tmp as /mnt/tmp, use environmnent variable for PATH_TO_FILE and run.
docker run -p 80:80 -v D:\tmp\:/mnt/tmp --env PATH_TO_FILE=/mnt/tmp/routing_response.json dockersample
Open browser localhost/getfile