After the image runs as a container and then you make a change in etc/cassandra/conf/cassandra.yaml and save/start the container, the changes are overriden from etc/cassandra/default.conf/cassandra.yaml. I am unable to find or figure out where and how this is happening.
As a Docker newbie, posted an issue at https://github.com/docker/docker/issues/19381#issuecomment-172150130 thinking it was a windows docker container issue and assuming this script is used "only once" (correct me if I am wrong) to build https://github.com/pokle/cassandra/blob/f46e178f845994b2466a153c2587577354b495bf/cassandra/src/start.sh#L23-L32 an initial image.
After the image runs as a container and then you make a change in etc/cassandra/conf/cassandra.yaml and save/start the container, the changes are overriden from etc/cassandra/default.conf/cassandra.yaml. I am unable to find or figure out where and how this is happening.