Include external network bridge for vpn agent

fix to make external network bridge configurable
in the vpn_agent.ini config file. Defaults to
nil.

Change-Id: Iddb6ff6296b8f2d42d97fdcb36a9819a4a995034
(cherry-picked from 3356503)

Author: Pradeep Kilambi

manifests/agents/vpnaas.pp

@@ -33,6 +33,9 @@
 # [*interface_driver*]
 #  (optional) Defaults to 'neutron.agent.linux.interface.OVSInterfaceDriver'.
 #
+# [*external_network_bridge]
+#  (optional) Defaults to undef
+#
 # [*ipsec_status_check_interval*]
 #   (optional) Status check interval. Defaults to '60'.
 #
@@ -41,6 +44,7 @@
   $enabled                     = true,
   $vpn_device_driver           = 'neutron.services.vpn.device_drivers.ipsec.OpenSwanDriver',
   $interface_driver            = 'neutron.agent.linux.interface.OVSInterfaceDriver',
+  $external_network_bridge     = undef,
   $ipsec_status_check_interval = '60'
 ) {
 
@@ -71,6 +75,16 @@
     'DEFAULT/interface_driver':          value => $interface_driver;
   }
 
+  if ($external_network_bridge) {
+    neutron_vpnaas_agent_config {
+      'DEFAULT/external_network_bridge': value => $external_network_bridge;
+    }
+  } else {
+    neutron_vpnaas_agent_config {
+      'DEFAULT/external_network_bridge': ensure => absent;
+    }
+  }
+
   if $::neutron::params::vpnaas_agent_package {
     Package['neutron']            -> Package['neutron-vpnaas-agent']
     Package['neutron-vpnaas-agent'] -> Neutron_vpnaas_agent_config<||>

spec/classes/neutron_agents_vpnaas_spec.rb

@@ -53,6 +53,19 @@
       should contain_neutron_vpnaas_agent_config('vpnagent/vpn_device_driver').with_value(p[:vpn_device_driver]);
       should contain_neutron_vpnaas_agent_config('ipsec/ipsec_status_check_interval').with_value(p[:ipsec_status_check_interval]);
       should contain_neutron_vpnaas_agent_config('DEFAULT/interface_driver').with_value(p[:interface_driver]);
+      should contain_neutron_vpnaas_agent_config('DEFAULT/external_network_bridge').with_ensure('absent');
+    end
+
+    context 'with external_network_bridge as br-ex' do
+      before do
+      params.merge!(
+        :external_network_bridge => 'br-ex'
+      )
+      end
+
+      it 'configures vpnaas_agent.ini' do
+        should contain_neutron_vpnaas_agent_config('DEFAULT/external_network_bridge').with_value(p[:external_network_bridge]);
+      end
     end
 
     it 'installs neutron vpnaas agent package' do