def ansible_inventory(<EOL>self,<EOL>keys=['<STR_LIT>', '<STR_LIT>', '<STR_LIT>'],<EOL>):
lansible = LagoAnsible(self._prefix)<EOL>return lansible.get_inventory_str(keys=keys)<EOL>
Get an Ansible inventory as a string, ``keys`` should be list on which
to group the hosts by. You can use any key defined in LagoInitFile.

Examples of possible `keys`:

    `keys=['disks/0/metadata/arch']`, would group the hosts by the
    architecture.

    `keys=['/disks/0/metadata/distro', 'disks/0/metadata/arch']`,
        would create groups by architecture and also by distro.

    `keys=['groups']` - would group hosts by the groups defined for
        each VM in the LagoInitFile, i.e.:

            domains:

                vm-01:
                    ...
                    groups: web-server
                    ..
                vm-02:
                    ..
                    groups: db-server


Args:
    keys (list of str): Path to the keys that will be used to
        create groups.

Returns:
    str: INI-like Ansible inventory