containers-storage copy - Copy content into a layer
containers-storage copy [--chown UID[:GID]] [sourceLayerNameOrID:]/path [...] targetLayerNameOrID:/path
Copies contents from a layer, or outside of layers, into a layer, performing ID mapping as appropriate.
Set owners for the new copies to the specified UID/GID pair. If the GID is not specified, the UID is used. The owner IDs are mapped as appropriate for the target layer.
containers-storage copy layer-with-mapping:/root/config.txt layer-with-different-mapping:/root/config.txt