Docker root dir cannot be found for nodes in Docker for AWS
This is because docker for aws uses a shell container when you ssh with the docker user (https://docs.docker.com/docker-for-aws/faqs/#what-are-the-editions-containers-running-after-deployment), so you don't actually have access to the host where the root dir is.
You can get access to the host through a privileged container, by first sshing with the docker user, then running something like: docker run --rm -it --privileged --pid=host debian nsenter -t 1 -m -u -n -i sh