nova/doc/api_samples/flavor-manage/v2.61/flavor-create-post-req.json

{
    "flavor": {
        "name": "test_flavor",
        "ram": 1024,
        "vcpus": 2,
        "disk": 10,
        "id": "10",
        "rxtx_factor": 2.0,
        "description": "test description"
    }
}