Backup a certain Snapshot of an Instance

LXD
1

I saw there are some discussions about lxc export vs. lxc publish container.
lxc export [<remote>:]<instance> [target] [--instance-only] [--optimized-storage] [flags]
lxc publish [<remote>:]<instance>[/<snapshot>] [<remote>:] [flags] [key=value...]

One feature missing in export, is the ability of aiming a specific container/snapshot as source.
lxc backup takes either container as source or container include all of its snapshots.
Is there a way to create a backup from a container/snapshot?
This would produce a downloadable backup tarball from a container/snapshot in one step!
The lxc publish way would be to create an image first, than publish that image.

2

It’s not very practical to implement because backups are tied to instances and so can’t easily be tied to just an instance snapshot. All the export logic also works with a full volume (and possibly its snasphots), doing this with a snapshot alone wouldn’t be trivial.

On the upside, there is an easy workaround you can use, copy the snapshot you want into a new instance, then export that. If you’re using a storage backend that supports copy on write (basically anything but dir), this is pretty much free and very fast.