# list all hosts:
lxc-ls -f -Fname,pid

# or get pid of one host:
lxc-ls -f -Fpid mycontainer
PID
-----
13323

cat /proc/13323/root/etc/hostname
# returns: "mycontainer"

#Non snap location on host:
ls /var/lib/lxd/storage-pools/STORAGE_POOL_NAME/containers/CONTAINER_NAME/rootfs/

#Snap location on host:
ls /var/snap/lxd/common/mntns/var/snap/lxd/common/lxd/storage-pools/STORAGE_POOL_NAME/containers/CONTAINER_NAME/rootfs/