Make package 'bridge-utils' install optional

When using puppet-nova with another big Puppet modules
this package may be defined before.

The solution is to make an installation optional.

Change-Id: I744fe89e8d9dae79a5b822ac1a1ad4cee780bfc4
Closes-Bug: #1445437

manifests/compute.pp

@@ -60,6 +60,11 @@
 #   (optional) Whether to use Neutron for networking of VMs
 #   Defaults to true
 #
+# [*install_bridge_utils*]
+#   (optional) Whether to install the bridge-utils package or not.
+#   Applicable only for cases when Neutron was disabled
+#   Defaults to true
+#
 # [*network_device_mtu*]
 #   (optional) The MTU size for the interfaces managed by nova
 #   Defaults to undef
@@ -120,6 +125,7 @@ class nova::compute (
   $force_config_drive                 = false,
   $virtio_nic                         = false,
   $neutron_enabled                    = true,
+  $install_bridge_utils               = true,
   $network_device_mtu                 = undef,
   $instance_usage_audit               = false,
   $instance_usage_audit_period        = 'month',
@@ -151,7 +157,7 @@ class nova::compute (
     'DEFAULT/vnc_keymap':                    value => $vnc_keymap;
   }
 
-  if $neutron_enabled != true {
+  if $neutron_enabled != true and $install_bridge_utils {
     # Install bridge-utils if we use nova-network
     package { 'bridge-utils':
       ensure => present,

spec/classes/nova_compute_spec.rb

@@ -121,6 +121,21 @@ describe 'nova::compute' do
           :before => 'Nova::Generic_service[compute]'
         )
       end
+
+    end
+
+    context 'with install_bridge_utils set to false' do
+      let :params do
+        { :install_bridge_utils => false }
+      end
+
+      it 'does not install bridge-utils package for nova-network' do
+        is_expected.to_not contain_package('bridge-utils').with(
+          :ensure => 'present',
+          :before => 'Nova::Generic_service[compute]'
+        )
+      end
+
     end
 
     context 'with vnc_enabled set to false' do