SparkOS/Dockerfile.image

# Dockerfile for building UEFI-bootable SparkOS image
# Creates a .img file with GPT partition table, ESP, and GRUB

FROM ubuntu:22.04 AS image-builder

# Install required tools
RUN apt-get update && \
    apt-get install -y \
    gcc \
    make \
    dosfstools \
    mtools \
    e2fsprogs \
    parted \
    gdisk \
    grub-efi-amd64-bin \
    grub-common \
    wget \
    busybox-static \
    kmod \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /build

# Copy source files
COPY src/ ./src/
COPY Makefile .
COPY scripts/ ./scripts/
COPY config/ ./config/
COPY rootfs/ ./rootfs/

# Build the init binary
RUN make init

# Download a minimal Linux kernel (using Ubuntu's kernel for now)
RUN mkdir -p /kernel && \
    apt-get update && \
    apt-get download linux-image-generic && \
    dpkg -x linux-image-*.deb /kernel && \
    rm -rf /var/lib/apt/lists/* linux-image-*.deb

# Create UEFI-bootable image with GPT partition table
RUN mkdir -p /output /mnt/esp /mnt/root && \
    echo "=== Creating UEFI-bootable SparkOS image with GRUB ===" && \
    # Create 1GB disk image (larger for kernel + bootloader)
    dd if=/dev/zero of=/output/sparkos.img bs=1M count=1024 && \
    \
    # Create GPT partition table
    echo "Creating GPT partition table..." && \
    parted -s /output/sparkos.img mklabel gpt && \
    \
    # Create EFI System Partition (ESP) - 200MB, FAT32
    echo "Creating EFI System Partition..." && \
    parted -s /output/sparkos.img mkpart ESP fat32 1MiB 201MiB && \
    parted -s /output/sparkos.img set 1 esp on && \
    \
    # Create root partition - remaining space, ext4
    echo "Creating root partition..." && \
    parted -s /output/sparkos.img mkpart primary ext4 201MiB 100% && \
    \
    # Set up loop device for the image
    LOOP_DEV=$(losetup -f) && \
    losetup -P $LOOP_DEV /output/sparkos.img && \
    \
    # Wait for partition devices
    sleep 1 && \
    \
    # Format partitions
    echo "Formatting EFI System Partition (FAT32)..." && \
    mkfs.vfat -F 32 -n "SPARKOSEFI" ${LOOP_DEV}p1 && \
    \
    echo "Formatting root partition (ext4)..." && \
    mkfs.ext4 -L "SparkOS" ${LOOP_DEV}p2 && \
    \
    # Mount ESP
    echo "Mounting partitions..." && \
    mount ${LOOP_DEV}p1 /mnt/esp && \
    mount ${LOOP_DEV}p2 /mnt/root && \
    \
    # Install GRUB to ESP
    echo "Installing GRUB bootloader..." && \
    mkdir -p /mnt/esp/EFI/BOOT && \
    \
    # Create GRUB EFI binary using grub-mkstandalone
    grub-mkstandalone \
        --format=x86_64-efi \
        --output=/mnt/esp/EFI/BOOT/BOOTX64.EFI \
        --locales="" \
        --fonts="" \
        "boot/grub/grub.cfg=/dev/null" && \
    \
    # Find the kernel
    KERNEL_PATH=$(find /kernel/boot -name "vmlinuz-*" | head -1) && \
    KERNEL_VERSION=$(basename $KERNEL_PATH | sed 's/vmlinuz-//') && \
    INITRD_PATH=$(find /kernel/boot -name "initrd.img-*" | head -1) && \
    \
    # Copy kernel and initrd to ESP
    echo "Installing kernel..." && \
    mkdir -p /mnt/esp/boot && \
    cp $KERNEL_PATH /mnt/esp/boot/vmlinuz && \
    if [ -f "$INITRD_PATH" ]; then cp $INITRD_PATH /mnt/esp/boot/initrd.img; fi && \
    \
    # Create GRUB configuration
    mkdir -p /mnt/esp/boot/grub && \
    printf '%s\n' \
        'set timeout=3' \
        'set default=0' \
        '' \
        'menuentry "SparkOS" {' \
        '    linux /boot/vmlinuz root=LABEL=SparkOS rw init=/sbin/init console=tty1 quiet' \
        '}' \
        > /mnt/esp/boot/grub/grub.cfg && \
    \
    # Set up root filesystem
    echo "Setting up root filesystem..." && \
    mkdir -p /mnt/root/{bin,sbin,etc,proc,sys,dev,tmp,usr/{bin,sbin,lib,lib64},var/{log,run},root,home/spark,boot} && \
    \
    # Install SparkOS init
    cp /build/init /mnt/root/sbin/init && \
    chmod 755 /mnt/root/sbin/init && \
    \
    # Install busybox
    echo "Installing busybox..." && \
    cp /bin/busybox /mnt/root/bin/busybox && \
    chmod 755 /mnt/root/bin/busybox && \
    \
    # Create busybox symlinks for essential commands
    for cmd in sh ls cat echo mount umount mkdir rm cp mv chmod chown ln ps kill; do \
        ln -sf busybox /mnt/root/bin/$cmd; \
    done && \
    \
    # Create system configuration files
    echo "sparkos" > /mnt/root/etc/hostname && \
    echo "127.0.0.1   localhost" > /mnt/root/etc/hosts && \
    echo "127.0.1.1   sparkos" >> /mnt/root/etc/hosts && \
    echo "root:x:0:0:root:/root:/bin/sh" > /mnt/root/etc/passwd && \
    echo "spark:x:1000:1000:SparkOS User:/home/spark:/bin/sh" >> /mnt/root/etc/passwd && \
    echo "root:x:0:" > /mnt/root/etc/group && \
    echo "spark:x:1000:" >> /mnt/root/etc/group && \
    \
    # Copy README to root partition
    cp /build/config/image-readme.txt /mnt/root/README.txt && \
    \
    # Sync and unmount
    echo "Finalizing image..." && \
    sync && \
    umount /mnt/esp && \
    umount /mnt/root && \
    losetup -d $LOOP_DEV && \
    \
    # Compress the image
    echo "Compressing image..." && \
    gzip -9 /output/sparkos.img && \
    echo "UEFI-bootable image created: /output/sparkos.img.gz"

# Final stage - export the image
FROM scratch AS export
COPY --from=image-builder /output/sparkos.img.gz /sparkos.img.gz