=================
Machinery Modules
=================

**Machinery** modules define how CAPE should interact with
your virtualization software (or potentially even with physical disk imaging
solutions).
Since we decided to not enforce any particular vendor, from release 0.4 you
can use your preferred solution and, in case it's not supported by
default, write a custom Python module that defines how to make CAPE use it.

Every machinery module should be located inside
*modules/machinery/*.

A basic machinery module would look like this:

    .. code-block:: python
        :linenos:

        from lib.cuckoo.common.abstracts import Machinery
        from lib.cuckoo.common.exceptions import CuckooMachineError

        class MyMachinery(Machinery):
            def start(self, label):
                try:
                    revert(label)
                    start(label)
                except SomethingBadHappens as e:
                    raise CuckooMachineError("OPS!")

            def stop(self, label):
                try:
                    stop(label)
                except SomethingBadHappens as e:
                    raise CuckooMachineError("OPS!")

The only requirements for Cuckoo are that:

    * The class inherits from ``Machinery``.
    * You have a ``start()`` and ``stop()`` functions.
    * You raise ``CuckooMachineError`` when something fails.

As you understand, the machinery module is a core part of a CAPE setup,
therefore make sure to spend enough time debugging your code and make it
solid and resistant to any unexpected error.

Configuration
=============

Every machinery module should come with a dedicated configuration file
located in *conf/<machinery module name>.conf*.
For example, for *modules/machinery/kvm.py* we have a *conf/kvm.conf*.

The configuration file should follow the default structure::

    [kvm]
    # Specify a comma-separated list of available machines to be used. For each
    # specified ID you have to define a dedicated section containing the details
    # on the respective machine. (E.g. cape1,cape2,cape3)
    machines = cape1

    [cape1]
    # Specify the label name of the current machine as specified in your
    # libvirt configuration.
    label = cape1

    # Specify the operating system platform used by current machine
    # [windows/darwin/linux].
    platform = windows

    # Specify the IP address of the current machine. Make sure that the IP address
    # is valid and that the host machine is able to reach it. If not, the analysis
    # will fail.
    ip = 192.168.122.105

The main section is called ``[<name of the module>]`` with a ``machines`` field
containing a comma-separated list of machines IDs.

For each machine, you should specify a ``label``, a ``platform``, and its
``ip``.

These fields are required by CAPE to use the already embedded ``initialize()``
function that generates the list of available machines.

If you plan to change the configuration structure you should override the ``initialize()``
function (inside your module, no need to modify CAPE's core code).
You can find its original code in the ``Machinery`` abstract inside
*lib/cuckoo/common/abstracts.py*.

LibVirt
=======

Starting with Cuckoo 0.5 developing new machinery modules based on LibVirt is easy.
Inside *lib/cuckoo/common/abstracts.py* you can find ``LibVirtMachinery`` that
already provides all the functionality for a LibVirt module.
Just inherit this base class and specify your connection string, as in
the example below:

    .. code-block:: python
        :linenos:

        from lib.cuckoo.common.abstracts import LibVirtMachinery

        class MyMachinery(LibVirtMachinery):
            # Set connection string.
            dsn = "my:///connection"


This works for all the virtualization technologies supported by LibVirt. Just remember to
check if your LibVirt package (if you are using one, for example from your Linux
distribution) is compiled with the support for the technology you need.

You can check it with the following command::

    $ virsh -V
    Virsh command line tool of libvirt 0.9.13
    See web site at http://libvirt.org/

    Compiled with support for:
     Hypervisors: QEmu/KVM LXC UML Xen OpenVZ VMWare Test
     Networking: Remote Daemon Network Bridging Interface Nwfilter VirtualPort
     Storage: Dir Disk Filesystem SCSI Multipath iSCSI LVM
     Miscellaneous: Nodedev AppArmor Secrets Debug Readline Modular

If you don't find your virtualization technology in the list of ``Hypervisors``, you will
need to recompile LibVirt with the specific support for the missing one.
