conf: Deprecate more nova-net options

They're multiplying!

Or not. A few nova-net options were removed in I4a6d534c9. Remove some
that we missed, updating the release note in the process.

Note that the 'auto_assign_floating_ip' is only used in the FloatingIP
mixin, which in turn is only used with various nova-network managers.
This means the option is dependent on the 'use_neutron' configuration
option like mostly ever other option in the file. As such, the help text
for that option is updated accordingly.

Change-Id: If396a7b10562e2fa43cdf4b09e4632cc6e57391a
Implements: bp centralize-config-options-ocata

nova/conf/floating_ips.py

@@ -36,14 +36,28 @@ Possible values:
 """),
     cfg.BoolOpt('auto_assign_floating_ip',
         default=False,
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+nova-network is deprecated, as are any related configuration options.
+""",
         help="""
 Autoassigning floating IP to VM
 
 When set to True, floating IP is auto allocated and associated
 to the VM upon creation.
+
+Related options:
+
+* use_neutron: this options only works with nova-network.
 """),
    cfg.StrOpt('floating_ip_dns_manager',
         default='nova.network.noop_dns_driver.NoopDNSDriver',
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+nova-network is deprecated, as are any related configuration options.
+""",
         help="""
 Full class name for the DNS Manager for floating IPs.
 
@@ -64,6 +78,11 @@ Related options:
 """),
     cfg.StrOpt('instance_dns_manager',
         default='nova.network.noop_dns_driver.NoopDNSDriver',
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+nova-network is deprecated, as are any related configuration options.
+""",
         help="""
 Full class name for the DNS Manager for instance IPs.
 
@@ -84,6 +103,11 @@ Related options:
 """),
     cfg.StrOpt('instance_dns_domain',
         default='',
+        deprecated_for_removal=True,
+        deprecated_since='15.0.0',
+        deprecated_reason="""
+nova-network is deprecated, as are any related configuration options.
+""",
         help="""
 If specified, Nova checks if the availability_zone of every instance matches
 what the database says the availability_zone should be for the specified

releasenotes/notes/deprecate-nova-network-opts-b6da6af4497ef4ca.yaml

@@ -28,3 +28,7 @@ deprecations:
     - ``dns_update_periodic_interval``
     - ``dhcp_domain``
     - ``use_neutron``
+    - ``auto_assign_floating_ip``
+    - ``floating_ip_dns_manager``
+    - ``instance_dns_manager``
+    - ``instance_dns_domain``