Introduce a new class to disable the default libvirt network

libvirt by default enables the default network so that it can provide
dhcp for all virtual machines running on that host. However this is not
required in OpenStack deployments and should be removed.

This change introduces a new class to disable the delete network.

Change-Id: Ibc0801694770913d494aa260161fa406689436ad

manifests/compute/libvirt/networks.pp

@@ -0,0 +1,40 @@
+# == Class: nova::compute::libvirt::networks
+#
+# Configures networks managed by libvirt
+#
+# === Parameters:
+#
+# [*disable_default_network*]
+#   (optional) Whether or not delete the default network.
+#   Defaults to true.
+#
+class nova::compute::libvirt::networks(
+  $disable_default_network = true,
+) {
+
+  include nova::deps
+
+  if $disable_default_network {
+    exec { 'libvirt-default-net-disable-autostart':
+      command => 'virsh net-autostart default --disable',
+      path    => ['/bin', '/usr/bin'],
+      onlyif  => [
+        'virsh net-info default 2>/dev/null',
+        'virsh net-info default 2>/dev/null | grep -i "^autostart:\s*yes"'
+      ]
+    }
+    exec { 'libvirt-default-net-destroy':
+      command => 'virsh net-destroy default',
+      path    => ['/bin', '/usr/bin'],
+      onlyif  => [
+        'virsh net-info default 2>/dev/null',
+        'virsh net-info default 2>/dev/null | grep -i "^active:\s*yes"'
+      ]
+    }
+
+    Service<| tag == 'libvirt-service' |>
+      -> Exec['libvirt-default-net-disable-autostart']
+      -> Exec['libvirt-default-net-destroy']
+      -> Service<| tag == 'nova-service' |>
+  }
+}

releasenotes/notes/libvirt-networks-742a45231f4ffdb3.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The new ``nova::compute::libvirt::networks`` class has been added. This
+    class can be used to disable the default libvirt network, which is not used
+    in OpenStack deployments.

spec/classes/nova_compute_libvirt_networks_spec.rb

@@ -0,0 +1,49 @@
+require 'spec_helper'
+
+describe 'nova::compute::libvirt::networks' do
+
+  shared_examples_for 'nova::compute::libvirt::networks' do
+
+    context 'with defaults' do
+      it { is_expected.to contain_exec('libvirt-default-net-disable-autostart').with(
+        :command => 'virsh net-autostart default --disable',
+        :path    => ['/bin', '/usr/bin'],
+        :onlyif  => [
+          'virsh net-info default 2>/dev/null',
+          'virsh net-info default 2>/dev/null | grep -i "^autostart:\s*yes"'
+        ]
+      ) }
+      it { is_expected.to contain_exec('libvirt-default-net-destroy').with(
+        :command => 'virsh net-destroy default',
+        :path    => ['/bin', '/usr/bin'],
+        :onlyif  => [
+          'virsh net-info default 2>/dev/null',
+          'virsh net-info default 2>/dev/null | grep -i "^active:\s*yes"'
+        ]
+      ) }
+    end
+
+    context 'when not disabling the default network' do
+      let :params do
+        {
+          :disable_default_network => false
+        }
+      end
+      it { is_expected.to_not contain_exec('libvirt-default-net-disable-autostart') }
+      it { is_expected.to_not contain_exec('libvirt-default-net-destroy') }
+    end
+  end
+
+  on_supported_os({
+     :supported_os => OSDefaults.get_supported_os
+   }).each do |os,facts|
+     context "on #{os}" do
+       let (:facts) do
+         facts.merge!(OSDefaults.get_facts())
+       end
+
+      it_configures 'nova::compute::libvirt::networks'
+     end
+  end
+
+end