Updated Docker images (9.18, 9.20, 9.21) - now based on Alpine Linux

[Marc]

> 
> > On 27. 8. 2024, at 18:57, Marc <Marc at f1-outsourcing.eu> wrote:
> >
> > Afaik  apk del \ does not free up space still.
> 
> Right. That was not really my intention though. I wanted to reduce
> the amount of cruft installed in the image.  The less binary stuff
> around, the less possible attack surface.
> 
> But apk --no-cache should work I guess.
> 
> > If you work with builder phase, you can probably shave of some MB's
> 
> 
> I think that's too complicated to use two phases, but I think the next
> update
> should reduce the image size a little bit.  It was ~170 MB before and the
> reduced (compressed) size is 130 MB.
> 
> But I get it - the base alpine:latest is only 3 MB, that's quite a
> difference.
> 

yes I would not be surprised if you can get a <50MB tar