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.. _datasource_nocloud:
NoCloud
*******
The data source ``NoCloud`` allows the user to provide user data and metadata
to the instance without running a network service (or even without having a
network at all).
You can provide metadata and user data to a local VM boot via files on a
`vfat`_ or `iso9660`_ filesystem. The filesystem volume label must be
``cidata`` or ``CIDATA``.
Alternatively, you can provide metadata via the kernel command line or SMBIOS
"serial number" option. The data must be passed in the form of a string: ::
ds=nocloud[;key=val;key=val]
or, ::
ds=nocloud-net[;key=val;key=val]
Permitted keys
==============
The permitted keys are:
* ``h`` or ``local-hostname``
* ``i`` or ``instance-id``
* ``s`` or ``seedfrom``
With ``ds=nocloud``, the ``seedfrom`` value must start with ``/`` or
``file://``. With ``ds=nocloud-net``, the ``seedfrom`` value must start
with ``http://`` or ``https://`` and end with a trailing ``/``.
Cloud-init performs variable expansion of the ``seedfrom`` URL for any DMI
kernel variables present in :file:`/sys/class/dmi/id` (kenv on FreeBSD).
Your ``seedfrom`` URL can contain variable names of the format
``__dmi.varname__`` to indicate to the ``cloud-init`` NoCloud datasource that
``dmi.varname`` should be expanded to the value of the DMI system attribute
wanted.
.. list-table:: Available DMI variables for expansion in ``seedfrom`` URL
:widths: 35 35 30
:header-rows: 0
* - ``dmi.baseboard-asset-tag``
- ``dmi.baseboard-manufacturer``
- ``dmi.baseboard-version``
* - ``dmi.bios-release-date``
- ``dmi.bios-vendor``
- ``dmi.bios-version``
* - ``dmi.chassis-asset-tag``
- ``dmi.chassis-manufacturer``
- ``dmi.chassis-serial-number``
* - ``dmi.chassis-version``
- ``dmi.system-manufacturer``
- ``dmi.system-product-name``
* - ``dmi.system-serial-number``
- ``dmi.system-uuid``
- ``dmi.system-version``
For example, you can pass this option to QEMU: ::
-smbios type=1,serial=ds=nocloud-net;s=http://10.10.0.1:8000/__dmi.chassis-serial-number__/
This will cause NoCloud to fetch the full metadata from a URL based on
YOUR_SERIAL_NUMBER as seen in :file:`/sys/class/dmi/id/chassis_serial_number`
(kenv on FreeBSD) from http://10.10.0.1:8000/YOUR_SERIAL_NUMBER/meta-data after
the network initialisation is complete.
File formats
============
These user data and metadata files are required as separate files at the
same base URL: ::
/user-data
/meta-data
Both files must be present for it to be considered a valid seed ISO.
Basically, ``user-data`` is simply :ref:`user data<user_data_formats>` and
``meta-data`` is a YAML-formatted file representing what you'd find in the EC2
metadata service.
You may also optionally provide a vendor data file adhering to
:ref:`user data formats<user_data_formats>` at the same base URL: ::
/vendor-data
Creating a disk
===============
Given a disk Ubuntu cloud image in :file:`disk.img`, you can create a
sufficient disk by following the following example.
1. Create the :file:`user-data` and :file:`meta-data` files that will be used
to modify the image on first boot.
.. code-block:: sh
$ echo -e "instance-id: iid-local01\nlocal-hostname: cloudimg" > meta-data
$ echo -e "#cloud-config\npassword: passw0rd\nchpasswd: { expire: False }\nssh_pwauth: True\n" > user-data
2. At this stage you have three options:
a. Create a disk to attach with some user data and metadata:
.. code-block:: sh
$ genisoimage -output seed.iso -volid cidata -joliet -rock user-data meta-data
b. Alternatively, create a ``vfat`` filesystem with the same files:
.. code-block:: sh
$ truncate --size 2M seed.iso
$ mkfs.vfat -n cidata seed.iso
* 2b) Option 1: mount and copy files:
.. code-block:: sh
$ sudo mount -t vfat seed.iso /mnt
$ sudo cp user-data meta-data /mnt
$ sudo umount /mnt
* 2b) Option 2: the ``mtools`` package provides ``mcopy``, which can
access ``vfat`` filesystems without mounting them:
.. code-block::
$ mcopy -oi seed.iso user-data meta-data
3. Create a new qcow image to boot, backed by your original image:
.. code-block:: sh
$ qemu-img create -f qcow2 -b disk.img -F qcow2 boot-disk.img
4. Boot the image and log in as "Ubuntu" with password "passw0rd":
.. code-block:: sh
$ kvm -m 256 \
-net nic -net user,hostfwd=tcp::2222-:22 \
-drive file=boot-disk.img,if=virtio \
-drive driver=raw,file=seed.iso,if=virtio
.. note::
Note that "passw0rd" was set as password through the user data above. There
is no password set on these images.
.. note::
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 the ``instance-id``, or start the
disk fresh.
Also, you can inject an :file:`/etc/network/interfaces` file by providing the
content for that file in the ``network-interfaces`` field of
:file:`meta-data`.
Example ``meta-data``
---------------------
::
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
Network configuration can also be provided to ``cloud-init`` in either
:ref:`network_config_v1` or :ref:`network_config_v2` by providing that
YAML formatted data in a file named :file:`network-config`. If found,
this file will override a :file:`network-interfaces` file.
See an example below. Note specifically that this file does not
have a top level ``network`` key as it is already assumed to
be network configuration based on the filename.
Example config
--------------
.. code-block:: yaml
version: 1
config:
- type: physical
name: interface0
mac_address: "52:54:00:12:34:00"
subnets:
- type: static
address: 192.168.1.10
netmask: 255.255.255.0
gateway: 192.168.1.254
.. code-block:: yaml
version: 2
ethernets:
interface0:
match:
macaddress: "52:54:00:12:34:00"
set-name: interface0
addresses:
- 192.168.1.10/255.255.255.0
gateway4: 192.168.1.254
.. _iso9660: https://en.wikipedia.org/wiki/ISO_9660
.. _vfat: https://en.wikipedia.org/wiki/File_Allocation_Table
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