Unpack local image

[Ludea]

Is your feature request related to a problem? Please describe.

I use cos toolkit to build a derivative.
When using arm builder, instead of unpack the built img, it pull and unpack downloaded img

Describe the solution you'd like

I would like to unpack a local image

Describe alternatives you've considered

Additional context

luet/pkg/helpers/docker/docker.go

Line 130 in bb88fe7

func DownloadAndExtractDockerImage(ctx *luettypes.Context, image, dest string, auth *types.AuthConfig, verify bool) (*images.Image, error) {

maybe split this func into 2 func and add an option to luet util unpackto specify local image name

[mudler]

good point, definetly luet util unpack can take an optional --local flag