#!/bin/sh
set -eux

OUTPUT="$1"

curl https://download.cirros-cloud.net/0.4.0/cirros-0.4.0-i386-disk.img > "$OUTPUT"

# prepare a cloud-init iso for disabling network source, to avoid a 90s timeout at boot
WORKDIR=$(mktemp -d)
trap "rm -rf '$WORKDIR'" EXIT INT QUIT PIPE
cd "$WORKDIR"

cat > meta-data <<EOF
{ "instance-id": "nocloud" }
EOF

cat > user-data <<EOF
#!/bin/sh
set -ex
sed -i 's/configdrive *//; s/ec2 *//' /etc/cirros-init/config
(sleep 1; poweroff) &
EOF

genisoimage -input-charset utf-8 -output cloud-init.iso -volid cidata -joliet -rock user-data meta-data

# boot it once with the cloud-init ISO
qemu-system-x86_64 -enable-kvm -nographic -net none \
    -drive file="$OUTPUT",if=virtio -cdrom cloud-init.iso