---
fixes:
  - |
    Fixes `bug 1662699`_ which was a regression in the v2.1 API from the
    ``block_device_mapping_v2.boot_index`` validation that was performed in the
    legacy v2 API. With this fix, requests to create a server with
    ``boot_index=None`` will be treated as if ``boot_index`` was not specified,
    which defaults to meaning a non-bootable block device.

    .. _bug 1662699: https://bugs.launchpad.net/nova/+bug/1662699