> you can run the Docker daemon itself under any combination of cgroup+namespace restrictions Not really though. The docker daemon needs access to the mount c

> you can run the Docker daemon itself under any combination of cgroup+namespace restrictions Not really though. The docker daemon needs access to the mount call, so it either must be root or root within its namespace. It's incredibly difficult to remove any meaningful permissions from the docker daemon. This is true to run any container, not just one that has bindmounts. The docker daemon was not built to be anything but root, and running it as "docker in docker" only works with "--privileged", which is to say, with no security restrictions.