Fix neutron issue w/ l2pop

This change resolves an issue where neutron is not able to bind to
a given port because l2 population is disabled and no vxlan multicast
group has been defined. To resolve this the `neutron_l2_population`
variable is being defined and set to "False" in the os_neutron defaults
and the vxlan multicast group will now contain a default value instead
of an empty string.

The change also removes the neutron_l2_population checks in the tasks
and templates because the variable is now being defined.

Change-Id: Ic2973626d88781bfc67a4275afcf9feffeb63f36
Closes-Bug: #1521793
Co-Authored-by: Ville Vuorinen <ville.vuorinen@multim.fi>
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>
(cherry picked from commit 00609ea56e)

playbooks/roles/os_neutron/defaults/main.yml

@@ -237,6 +237,9 @@ neutron_dhcp_config:
 neutron_ml2_drivers_type: "flat,vlan,vxlan,local"
 neutron_ml2_mechanism_drivers: "linuxbridge,l2population"
 
+# Enable or disable L2 Population.
+neutron_l2_population: "False"
+
 ## Set this to configure overlay networks. The default is set as an empty hash.
 # neutron_overlay_network:
 #   address: "172.29.241.248"
@@ -249,7 +252,7 @@ neutron_overlay_network: {}
 ## The neutron multicast group address. This should be set as a host variable if used.
 ## This defaults to an empty string
 # neutron_vxlan_group: 239.1.1.100
-neutron_vxlan_group: ""
+neutron_vxlan_group: "239.1.1.1"
 
 ## Set this variable to configure the provider networks that will be available
 ## When setting up networking in things like the ml2_conf.ini file. Normally

playbooks/roles/os_neutron/tasks/neutron_post_install.yml

@@ -13,26 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Disable L2 population for L3HA support
-  set_fact:
-    neutron_l2_population: "False"
-  when:
-    - neutron_plugin_type == 'ml2'
-    - groups['neutron_agent'] | length >= 2
-    - neutron_services['neutron-linuxbridge-agent']['service_en'] | bool
-    - neutron_l2_population is undefined
-  tags:
-    - neutron-config
-
-- name: Enable L2 population support
-  set_fact:
-    neutron_l2_population: "True"
-  when:
-    - neutron_plugin_type == 'ml2'
-    - neutron_l2_population is undefined
-  tags:
-    - neutron-config
-
 - name: Copy neutron config
   config_template:
     src: "{{ item.src }}"

playbooks/roles/os_neutron/templates/neutron.conf.j2

@@ -55,7 +55,7 @@ agent_down_time = {{ neutron_agent_down_time }}
 
 {% set num_agent = groups['neutron_agent'] | length %}
 {% if neutron_plugin_type == 'ml2' and num_agent >= 2 %}
-{% if neutron_services['neutron-linuxbridge-agent']['service_en'] | bool and not neutron_l2_population | bool %}
+{% if neutron_services['neutron-linuxbridge-agent']['service_en'] | bool %}
 
 {% set max_l3_router = num_agent if num_agent > 2 else 2 %}
 {% set min_l3_router = num_agent if (num_agent > 2 and num_agent < max_l3_router) else 2 %}