Handle ovs_use_veth option

Change-Id: I3331ddae9840d9b1ae3dc07e4065684fbb1ab15f
Closes-Bug: PROD-21373
diff --git a/README.rst b/README.rst
index 7e63a20..34d660e 100644
--- a/README.rst
+++ b/README.rst
@@ -211,6 +211,7 @@
         version: mitaka
         dhcp_lease_duration: 600
         firewall_driver: iptables_hybrid
+        ovs_use_veth: False
         message_queue:
           engine: rabbitmq
           host: 127.0.0.1
diff --git a/neutron/files/pike/dhcp_agent.ini b/neutron/files/pike/dhcp_agent.ini
index 0b2c60f..437d3d1 100644
--- a/neutron/files/pike/dhcp_agent.ini
+++ b/neutron/files/pike/dhcp_agent.ini
@@ -15,6 +15,9 @@
 # Uses veth for an OVS interface or not. Support kernels with limited namespace support (e.g. RHEL 6.5) so long as ovs_use_veth is set to
 # True. (boolean value)
 #ovs_use_veth = false
+{%- if neutron.ovs_use_veth is defined %}
+ovs_use_veth = {{ neutron.ovs_use_veth }}
+{%- endif %}
 
 # MTU setting for device. This option will be removed in Newton. Please use the system-wide global_physnet_mtu setting which the agents will
 # take into account when wiring VIFs. (integer value)
diff --git a/neutron/files/pike/l3_agent.ini b/neutron/files/pike/l3_agent.ini
index 7b386a5..85ca1a9 100644
--- a/neutron/files/pike/l3_agent.ini
+++ b/neutron/files/pike/l3_agent.ini
@@ -18,6 +18,9 @@
 # support (e.g. RHEL 6.5) so long as ovs_use_veth is set to True. (boolean
 # value)
 #ovs_use_veth = false
+{%- if neutron.ovs_use_veth is defined %}
+ovs_use_veth = {{ neutron.ovs_use_veth }}
+{%- endif %}
 
 # The driver used to manage the virtual interface. (string value)
 #interface_driver = <None>
diff --git a/neutron/files/queens/dhcp_agent.ini b/neutron/files/queens/dhcp_agent.ini
index ec530ed..b16e956 100644
--- a/neutron/files/queens/dhcp_agent.ini
+++ b/neutron/files/queens/dhcp_agent.ini
@@ -16,6 +16,9 @@
 # support (e.g. RHEL 6.5) and rate limiting on router's gateway port so long as
 # ovs_use_veth is set to True. (boolean value)
 #ovs_use_veth = false
+{%- if neutron.ovs_use_veth is defined %}
+ovs_use_veth = {{ neutron.ovs_use_veth }}
+{%- endif %}
 
 # The driver used to manage the virtual interface. (string value)
 #interface_driver = <None>
diff --git a/neutron/files/queens/l3_agent.ini b/neutron/files/queens/l3_agent.ini
index 69e97be..b3fcdfa 100644
--- a/neutron/files/queens/l3_agent.ini
+++ b/neutron/files/queens/l3_agent.ini
@@ -18,6 +18,9 @@
 # support (e.g. RHEL 6.5) and rate limiting on router's gateway port so long as
 # ovs_use_veth is set to True. (boolean value)
 #ovs_use_veth = false
+{%- if neutron.ovs_use_veth is defined %}
+ovs_use_veth = {{ neutron.ovs_use_veth }}
+{%- endif %}
 
 # The driver used to manage the virtual interface. (string value)
 #interface_driver = <None>
diff --git a/tests/pillar/gateway_legacy.sls b/tests/pillar/gateway_legacy.sls
index c67c80b..c2606f3 100644
--- a/tests/pillar/gateway_legacy.sls
+++ b/tests/pillar/gateway_legacy.sls
@@ -3,6 +3,7 @@
     agent_mode: legacy
     dhcp_lease_duration: 86400
     firewall_driver: noop
+    ovs_use_veth: True
     backend:
       engine: ml2
       tenant_network_types: "flat,vxlan"