Add new DEFAULT option named "my_ip"

Add a new parameter in config named "my_ip".
The default value for my_ip will be the IPv4 of the interface used for
default gateway.

This new option is not used for now in any neutron code, but may be
used by operators to configure other options (like local_ip,
ovsdb_connection, etc.).

Signed-off-by: Arnaud Morin <arnaud.morin@gmail.com>
Change-Id: Idee31f2c4fed992ed63a51bfbb8d6e2ebb54cf5d

neutron/conf/common.py

@@ -17,6 +17,7 @@ from neutron_lib import constants
 from neutron_lib.utils import net
 from oslo_config import cfg
 from oslo_service import wsgi
+from oslo_utils import netutils
 
 from neutron._i18n import _
 
@@ -151,6 +152,10 @@ core_opts = [
                        '2. DHCP scheduler API extension '
                        '3. Network scheduling mechanism '
                        '4. DHCP RPC/notification')),
+    cfg.StrOpt('my_ip', default=netutils.get_my_ipv4(),
+               help=_('IPv4 address of this host. If no address is provided '
+                      'and one cannot be determined, 127.0.0.1 will be '
+                      'used.')),
 ]
 
 core_cli_opts = [

releasenotes/notes/new-my-ip-config-b8efeb05dd50cfd6.yaml

@@ -0,0 +1,9 @@
+---
+other:
+  - |
+    Add a new config option in DEFAULT section named ``my_ip``.
+    This new config option will be set by default to the local IPv4 configured
+    to reach the default gateway.
+    This new setting might be useful for operators that need to configure this
+    IP in another part of their config (like OVS/local_ip) without relying on
+    any external templating system.