first-boot

[leifliddy]

In this script, it might a good idea to verify that $root_dev and $efi_dev both have value before changing any of the UUIDs If the efi partition wasn't mount for whatever reason, but root was -- then the UUID of the root partition would be modified, but /etc/fstab wouldn't be modified.

I actually ran into this issue when building my own image (and incorporating your scripts). For some reason the efi partition wasn't mounted when the first-boot.service ran....

root_dev=$(findmnt -n -o SOURCE /)
efi_dev=$(findmnt -n -o SOURCE /boot/efi)

if [ -e "$root_dev" ]; then
    echo 'Randomizing root filesystem UUID...'
    tune2fs -U random "$root_dev"

    root_uuid=$(blkid -c /dev/null "$root_dev" -o export | grep '^UUID=')
    echo "Root filesystem: $root_uuid"
    echo
fi

if [ -e "$efi_dev" ] && \
    blkid "$efi_dev" | grep -q 'TYPE="vfat"'; then

    echo Randomizing EFI system partition UUID...'
    # Ugly... why isn't there a command to do this?
    ssize=$(blockdev --getss "$efi_dev")
    dd bs=1 seek=67 count=4 conv=notrunc if=/dev/urandom of="$efi_dev"
    dd bs=1 skip=67 seek=$((67+6*$ssize)) count=4 conv=notrunc if="$efi_dev" of="$efi_dev"

    efi_uuid=$(blkid -c /dev/null "$efi_dev" -o export | grep '^UUID=')
    echo "EFI partition: $efi_uuid"
    echo
fi

if [ ! -z "$root_uuid" ] && [ ! -z "$efi_uuid" ]; then

[leifliddy]

something like this should work....

root_dev=$(findmnt -n -o SOURCE /)
efi_dev=$(findmnt -n -o SOURCE /boot/efi)

if [ -n "$root_dev" ] && [ -n "$efi_dev" ]; then
    if [ "$(blkid "$efi_dev" | tr -d '"' | grep 'TYPE=vfat')" ]; then
        echo "Randomizing root filesystem UUID..."
        tune2fs -U random "$root_dev"

        root_uuid="$(blkid -c /dev/null "$root_dev" -o export | grep '^UUID=')"
        echo "Root filesystem: $root_uuid"

        echo -e '\nRandomizing EFI system partition UUID...'
        # Ugly... why isn't there a command to do this?
        ssize="$(blockdev --getss "$efi_dev")"
        dd bs=1 seek=67 count=4 conv=notrunc if=/dev/urandom of="$efi_dev"
        dd bs=1 skip=67 seek=$((67+6*$ssize)) count=4 conv=notrunc if="$efi_dev" of="$efi_dev"

        efi_uuid=$(blkid -c /dev/null "$efi_dev" -o export | grep '^UUID=')
        echo -e "EFI partition: $efi_uuid\n"
    fi
fi

if [ -n "$root_uuid" ] && [ -n "$efi_uuid" ]; then
....