# look for the ID of the `default` VM
vagrant global-status

vagrant ssh <default-id>

# install nsenter
docker run -v /usr/local/bin:/target jpetazzo/nsenter

# get the container id, not the image id
docker ps

PID=$(docker inspect --format {{.State.Pid}} <container-id>)

sudo nsenter --target $PID --mount --uts --ipc --net --pid