One should be able to set path_mtu value for neutron

Customer-Found
Change-Id: Ie100e957aeeba3a8e1747513b0793aeee5b7cd76
diff --git a/README.rst b/README.rst
index 416f93b..502d5c5 100644
--- a/README.rst
+++ b/README.rst
@@ -157,6 +157,7 @@
     neutron:
       server:
         version: mitaka
+        path_mtu: 1500
         bind:
           address: 172.20.0.1
           port: 9696
diff --git a/neutron/files/mitaka/ml2_conf.ini b/neutron/files/mitaka/ml2_conf.ini
index 2b8dab3..c148e61 100644
--- a/neutron/files/mitaka/ml2_conf.ini
+++ b/neutron/files/mitaka/ml2_conf.ini
@@ -113,7 +113,7 @@
 # Maximum size of an IP packet (MTU) that can traverse the underlying physical network infrastructure without fragmentation for
 # overlay/tunnel networks. In most cases, use the same value as the global_physnet_mtu option. (integer value)
 #path_mtu = 1500
-path_mtu = {{ server.get('global_physnet_mtu', '1500') }}
+path_mtu = {{ server.get('path_mtu', server.get('global_physnet_mtu', '1500')) }}
 
 # A list of mappings of physical networks to MTU values. The format of the mapping is <physnet>:<mtu val>. This mapping allows specifying a
 # physical network MTU value that differs from the default global_physnet_mtu value. (list value)
diff --git a/neutron/files/newton/ml2_conf.ini b/neutron/files/newton/ml2_conf.ini
index 2b8dab3..c148e61 100644
--- a/neutron/files/newton/ml2_conf.ini
+++ b/neutron/files/newton/ml2_conf.ini
@@ -113,7 +113,7 @@
 # Maximum size of an IP packet (MTU) that can traverse the underlying physical network infrastructure without fragmentation for
 # overlay/tunnel networks. In most cases, use the same value as the global_physnet_mtu option. (integer value)
 #path_mtu = 1500
-path_mtu = {{ server.get('global_physnet_mtu', '1500') }}
+path_mtu = {{ server.get('path_mtu', server.get('global_physnet_mtu', '1500')) }}
 
 # A list of mappings of physical networks to MTU values. The format of the mapping is <physnet>:<mtu val>. This mapping allows specifying a
 # physical network MTU value that differs from the default global_physnet_mtu value. (list value)
diff --git a/neutron/files/ocata/ml2_conf.ini b/neutron/files/ocata/ml2_conf.ini
index b61e313..bc4d811 100644
--- a/neutron/files/ocata/ml2_conf.ini
+++ b/neutron/files/ocata/ml2_conf.ini
@@ -158,7 +158,7 @@
 # protocol. This option allows specifying a physical network MTU value that
 # differs from the default global_physnet_mtu value. (integer value)
 #path_mtu = 0
-path_mtu = {{ server.get('global_physnet_mtu', '1500') }}
+path_mtu = {{ server.get('path_mtu', server.get('global_physnet_mtu', '0')) }}
 
 # A list of mappings of physical networks to MTU values. The format of the
 # mapping is <physnet>:<mtu val>. This mapping allows specifying a physical
diff --git a/tests/pillar/control_cluster.sls b/tests/pillar/control_cluster.sls
index 763b549..bebff8c 100644
--- a/tests/pillar/control_cluster.sls
+++ b/tests/pillar/control_cluster.sls
@@ -2,6 +2,7 @@
   server:
     enabled: true
     fwaas: false
+    path_mtu: 1500
     dns_domain: novalocal
     tunnel_type: vxlan
     version: liberty