FROM alpine:3.22@sha256:4b7ce07002c69e8f3d704a9c5d6fd3053be500b7f1c69fc0d80990c2ad8dd412 AS rootfs
RUN apk --no-cache add alpine-base tzdata ifupdown-ng agetty
RUN rc-update add devfs sysinit && \
    rc-update add dmesg sysinit && \
    rc-update add mdev sysinit && \
    rc-update add cgroups sysinit && \
    rc-update add sysctl boot && \
    rc-update add hostname boot && \
    rc-update add bootmisc boot && \
    rc-update add networking boot && \
    rc-update add syslog boot && \
    rc-update add mount-ro shutdown && \
    rc-update add killprocs shutdown && \
    rc-update add savecache shutdown && \
    ln -s /sbin/init /init && \
    echo 'root:root' | chpasswd && \
    echo 'sprout' > /etc/hostname && \
    rm /etc/motd && \
    ln -s /usr/share/zoneinfo/UTC /etc/localtime && \
    echo 'hvc0::respawn:/sbin/agetty --autologin root -L hvc0 115200 vt100' >> /etc/inittab
COPY files/interfaces /etc/network/interfaces

FROM alpine:3.22@sha256:4b7ce07002c69e8f3d704a9c5d6fd3053be500b7f1c69fc0d80990c2ad8dd412 AS build
COPY --from=rootfs / /rootfs
WORKDIR /rootfs
RUN find . | cpio -R 0:0 --ignore-devno --renumber-inodes -o -H newc --quiet > /initramfs

FROM scratch AS final
COPY --from=build /initramfs /initramfs