network/dhcp: templatize dnsmasq configuration

The only way I found to fix the MTU configuration is to use DHCP.
To do that, we need to configure Neutron DHCP Agent and create a
dedicated file. This file has been introduced as a new template.

Close bug #270

Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>

manifests/network/dhcp.pp

@@ -17,7 +17,8 @@
 #
 
 class cloud::network::dhcp(
-  $debug   = $os_params::debug
+  $veth_mtu = $os_params::veth_mtu,
+  $debug    = $os_params::debug
 ) {
 
   include 'cloud::network'
@@ -26,4 +27,16 @@ class cloud::network::dhcp(
     debug   => $debug
   }
 
+  neutron_dhcp_agent_config {
+    'DEFAULT/dnsmasq_config_file': value => '/etc/neutron/dnsmasq-neutron.conf';
+  }
+
+  file { '/etc/neutron/dnsmasq-neutron.conf':
+    content => template('cloud/network/dnsmasq-neutron.conf.erb'),
+    owner   => 'root',
+    mode    => '0755',
+    group   => 'root',
+    notify  => Service['neutron-dhcp-agent']
+  }
+
 }

spec/classes/cloud_network_dhcp_spec.rb

@@ -37,7 +37,8 @@ describe 'cloud::network::dhcp' do
     end
 
     let :params do
-      { :debug => true }
+      { :veth_mtu => '1400',
+        :debug    => true }
     end
 
     it 'configure neutron common' do
@@ -77,6 +78,15 @@ describe 'cloud::network::dhcp' do
       should contain_class('neutron::agents::dhcp').with(
           :debug => true
       )
+
+      should contain_neutron_dhcp_agent_config('DEFAULT/dnsmasq_config_file').with_value('/etc/neutron/dnsmasq-neutron.conf')
+
+      should contain_file('/etc/neutron/dnsmasq-neutron.conf').with(
+        :mode => '0755',
+        :owner => 'root',
+        :group => 'root'
+      )
+      verify_contents(subject, '/etc/neutron/dnsmasq-neutron.conf', ["dhcp-options-force=26,1400"])
     end
   end
 

templates/network/dnsmasq-neutron.conf.erb

@@ -0,0 +1 @@
+dhcp-options-force=26,<%= @veth_mtu %>