FROM alpine AS mirror

RUN mkdir -p /out/etc/apk && cp -r /etc/apk/* /out/etc/apk/
RUN apk add --no-cache --initdb -p /out \
    dosfstools \
    syslinux \
    grub-bios grub-efi
RUN rm -rf /out/etc/apk /out/lib/apk /out/var/cache

FROM scratch
COPY --from=mirror /out/ /