#!/bin/sh

burl="http://cloud-images.ubuntu.com/releases/xenial"
goodurl="$burl/release-20161214/ubuntu-16.04-server-cloudimg-amd64-disk1.img"
badurl="$burl/release-20161221/ubuntu-16.04-server-cloudimg-amd64-disk1.img"
good_qcow="good-disk1.qcow"
bad_qcow="bad-disk1.qcow"

fail() { echo "$@" 1>&2; exit 1; }
msg() { echo "$@" 1>&2; }

set -f
for stuff in "good $goodurl" "bad $badurl"; do
    set -- $stuff
    pre="$1"; url="$2"
    qcow="$pre-disk1.qcow"
    img="$pre-disk1.img"
    if [ ! -f "$img" ]; then
        msg "downloading $pre from $url"
        wget "$url" -O "$img.tmp" && mv "$img.tmp" "$img" ||
           fail "failed downlaod $url"
    fi
    if [ ! -f "$qcow" ]; then
        # patch the image to have root:root login and disable cloud-init
        msg "converting $img to qcow (uncompressing)"
        qemu-img convert -O qcow2 "$img" "$qcow.tmp" &&
            msg "disabling cloud-init, setting passwd" &&
            sudo mount-image-callback -vv "$qcow.tmp" -- sh -xc '
                touch $MOUNTPOINT/etc/cloud/cloud-init.disabled
                echo "root:root" | chroot "$MOUNTPOINT" chpasswd
            ' &&
            mv "$qcow.tmp" "$qcow" ||
            fail "failed convert $img to $qcow"
    fi
    if [ ! -f "$pre-kernel" -a ! -f "$pre-initrd" ]; then
        # copy out kernel and initramfs for easier booting
        sudo mount-image-callback --read-only "$qcow" -- sh -c '
            kernel=$1; initrd=$2; info="$3" manif="$4"
            cp -v $MOUNTPOINT/boot/vmlinu?* "$kernel"
            cp -v $MOUNTPOINT/boot/initrd.img-* "$initrd"
            t=$(echo "${MOUNTPOINT}/boot/"vmlinu?*)
            t=${t##*/}
            echo "$t"> $info
            chroot $MOUNTPOINT dpkg-query --show > "$manif"
            chown $SUDO_UID:$SUDO_GID "$kernel" "$initrd" "$info" "$manif"' -- \
            $pre-kernel $pre-initrd $pre-kinfo $pre-manifest || {
                rm -f "$pre-kernel" "$pre-initrd"
                fail "failed copy kernel from $qcow [$pre]"
            }
        msg "wrote $pre-kernel and $pre-initrd"
    fi
done

cat <<EOF
Bug 1651602 http://pad.lv/1651602

System cannot boot off nvme disk with LABEL=cloudimg-rootfs
  
The good-kernel and good-initrd will work, but
bad-kernel and bad-initrd will not.

pre=good; qemu-system-x86_64 -enable-kvm -drive \\
    file=\$pre-disk1.qcow,if=none,format=qcow2,id=nvme0 \\
    -device nvme,drive=nvme0,serial=nvme-0 \\
    -snapshot -nographic -echr 0x05 \\
    -kernel \$pre-kernel -initrd \$pre-initrd \\
    -append "root=LABEL=cloudimg-rootfs console=ttyS0"
EOF