The data source 'NoCloud' and 'NoCloudNet' allow the user to provide user-data
and meta-data to the instance without running a network service (or even without
having a network at all)

You can provide meta-data and user-data to a local vm boot via files on a vfat
or iso9660 filesystem.  These user-data and meta-data files are expected to be
in the format described in doc/example/seed/README .  Basically, user-data is
simply user-data and meta-data is a yaml formated file representing what you'd
find in the EC2 metadata service.

Given a disk 12.04 cloud image in 'disk.img', you can create a sufficient disk
by following the example below.

## create user-data and meta-data files that will be used
## to modify image on first boot
$ { echo instance-id: iid-local01; echo local-hostname: cloudimg; } > meta-data

$ printf "#cloud-config\npassword: passw0rd\nchpasswd: { expire: False }\nssh_pwauth: True\n" > user-data

## create a disk to attach with some user-data and meta-data
$ genisoimage  -output seed.iso -volid cidata -joliet -rock user-data meta-data

## alternatively, create a vfat filesystem with same files
## $ truncate --size 2M seed.img
## $ mkfs.vfat -n cidata seed.img
## $ mcopy -oi seed.img user-data meta-data ::

## create a new qcow image to boot, backed by your original image
$ qemu-img create -f qcow2 -b disk.img boot-disk.img

## boot the image and login as 'ubuntu' with password 'passw0rd'
## note, passw0rd was set as password through the user-data above,
## there is no password set on these images.
$ kvm -m 256 \
   -net nic -net user,hostfwd=tcp::2222-:22 \
   -drive file=boot-disk.img,if=virtio \
   -drive file=seed.iso,if=virtio

Note, that the instance-id provided ('iid-local01' above) is what is used to
determine if this is "first boot".  So if you are making updates to user-data
you will also have to change that, or start the disk fresh.


Also, you can inject an /etc/network/interfaces file by providing the content
for that file in the 'network-interfaces' field of metadata.  Example metadata:
  instance-id: iid-abcdefg
  network-interfaces: |
    iface eth0 inet static
    address 192.168.1.10
    network 192.168.1.0
    netmask 255.255.255.0
    broadcast 192.168.1.255
    gateway 192.168.1.254
  hostname: myhost