---
features:
  - When booting an instance, its sanitized 'hostname' attribute is now used to
    populate the 'dns_name' attribute of the Neutron ports the instance is
    attached to.
    This functionality enables the Neutron internal DNS service to know the
    ports by the instance's hostname. As a consequence, commands like
    'hostname -f' will work as expected when executed in the instance.
    When a port's network has a non-blank 'dns_domain' attribute, the port's
    'dns_name' combined with the network's 'dns_domain' will be published by
    Neutron in an external DNS as a service like Designate. As a consequence,
    the instance's hostname is published in the external DNS as a service.
    This functionality is added to Nova when the 'DNS Integration' extension
    is enabled in Neutron.
    The publication of 'dns_name' and 'dns_domain' combinations to an external
    DNS as a service additionally requires the configuration of the appropriate
    driver in Neutron.
    When the 'Port Binding' extension is also enabled in Neutron, the
    publication of a 'dns_name' and 'dns_domain' combination to the external
    DNS as a service will require one additional update operation when Nova
    allocates the port during the instance boot. This may have a noticeable
    impact on the performance of the boot process.
