cinder/cinder/tests/functional/api_sample_tests/samples/volume_manage_extensions/volume-manage-request.json.tpl

{
    "volume": {
        "host": "%(host)s",
        "ref": {
            "source-name": "existingLV",
            "source-id": "1234"
        },
        "name": "New Volume",
        "availability_zone": "az2",
        "description": "Volume imported from existingLV",
        "volume_type": null,
        "bootable": true,
        "metadata": {
            "key1": "value1",
            "key2": "value2"
        }
    }
}