Add plugin config file to /etc/default/neutron-server

Debian platforms uses /etc/default/neutron-server to tell
neutron-server service which plugin configuration file to load.

Configure it.

Change-Id: I0638d2584ad327ae1ed77f672d5efb1c28064aa2
Closes-bug: #1357431
(cherry picked from commit c848aff)

manifests/plugins/ml2.pp

@@ -112,6 +112,17 @@
     warning('Without networking mechanism driver, ml2 will not communicate with L2 agents')
   }
 
+  if $::osfamily == 'Debian' {
+    file_line { '/etc/default/neutron-server:NEUTRON_PLUGIN_CONFIG':
+      path    => '/etc/default/neutron-server',
+      match   => '^NEUTRON_PLUGIN_CONFIG=(.*)$',
+      line    => 'NEUTRON_PLUGIN_CONFIG=/etc/neutron/plugin.ini',
+      require => File['/etc/neutron/plugin.ini'],
+    }
+    File_line['/etc/default/neutron-server:NEUTRON_PLUGIN_CONFIG']
+    ~> Service<| title == 'neutron-server' |>
+  }
+
   # In RH, the link is used to start Neutron process but in Debian, it's used only
   # to manage database synchronization.
   file {'/etc/neutron/plugin.ini':

spec/classes/neutron_plugins_ml2_spec.rb

@@ -178,6 +178,15 @@
       {}
     end
 
+    it 'configures /etc/default/neutron-server' do
+      should contain_file_line('/etc/default/neutron-server:NEUTRON_PLUGIN_CONFIG').with(
+        :path    => '/etc/default/neutron-server',
+        :match   => '^NEUTRON_PLUGIN_CONFIG=(.*)$',
+        :line    => 'NEUTRON_PLUGIN_CONFIG=/etc/neutron/plugin.ini',
+        :require => ['File[/etc/neutron/plugin.ini]']
+      )
+    end
+
     context 'on Ubuntu operating systems' do
       before do
         facts.merge!({:operatingsystem => 'Ubuntu'})