Refer: https://discuss.linuxcontainers.org/t/backup-the-container-and-install-it-on-another-server/463/4
lxc publish CONTAINER_NAME/SNAPSHOT_NAME --alias my-export
lxc image export my-export .
This will create a new LXD image from your container and export it as a tarball in your current directory. You can then ship that tarball to your target host and do:
lxc image import TARBALL --alias my-export
lxc init my-export NEW-CONTAINER
or
To clone a container, you'd just do "lxc copy SOURCE DESTINATION", but that's on a single local LXD. In your case, it looks like you're trying to test your backup mechanism.
Say you have a container called "blah". For backup as an image tarball, you'd do:
lxc snapshot blah backup
lxc publish blah/backup --alias blah-backup
lxc image export blah-backup .
lxc image delete blah-backup
Which will get you a tarball in your current directory.
To restore and create a container from it, you can then do:
lxc image import TARBALL-NAME --alias blah-backup
lxc launch blah-backup some-container-name
lxc image delete blah-backup