Add parameter to specify host_uuid

Currently, the `override_uuid` parameter, if set, will generate a random
uuid to be set in libvirtd.conf. It might be desirable to set a specific
uuid instead of a random one, create a parameter to do so.

Change-Id: I981a80d9767b7eae0854a64df720c23f855ab1be

manifests/migration/libvirt.pp

@@ -79,6 +79,11 @@
 #   (optional) Set uuid not equal to output from dmidecode (boolean)
 #   Defaults to false
 #
+# [*host_uuid*]
+#   (optional) Set host_uuid to this value, instead of generating a random
+#   uuid, if override_uuid is set to true.
+#   Defaults to undef
+#
 # [*configure_libvirt*]
 #   (optional) Whether or not configure libvirt bits.
 #   Defaults to true.
@@ -130,6 +135,7 @@ class nova::migration::libvirt(
   $live_migration_permit_post_copy     = $::os_service_default,
   $live_migration_permit_auto_converge = $::os_service_default,
   $override_uuid                       = false,
+  $host_uuid                           = undef,
   $configure_libvirt                   = true,
   $configure_nova                      = true,
   $client_user                         = undef,
@@ -217,19 +223,21 @@ class nova::migration::libvirt(
 
     if $override_uuid {
       if ! $::libvirt_uuid {
-        $host_uuid = generate('/bin/cat', '/proc/sys/kernel/random/uuid')
+        $host_uuid_real = pick(
+          $host_uuid,
+          generate('/bin/cat', '/proc/sys/kernel/random/uuid'))
         file { '/etc/libvirt/libvirt_uuid':
-          content => $host_uuid,
+          content => $host_uuid_real,
           require => Package['libvirt'],
         }
       } else {
-        $host_uuid = $::libvirt_uuid
+        $host_uuid_real = $::libvirt_uuid
       }
 
       augeas { 'libvirt-conf-uuid':
         context => '/files/etc/libvirt/libvirtd.conf',
         changes => [
-          "set host_uuid ${host_uuid}",
+          "set host_uuid ${host_uuid_real}",
         ],
         notify  => Service['libvirt'],
         require => Package['libvirt'],

releasenotes/notes/add-libvirtd-host_uuid-ff1ab95e4586d176.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Add a new paramter nova::migration::libvirt::host_uuid. Currently, the
+    host_uuid is autogenerated (if override_uuid = true). This means an
+    operator is unable to set a uuid if desired. Add a new parameter to specify
+    host_uuid.

spec/classes/nova_migration_libvirt_spec.rb

@@ -64,6 +64,24 @@ describe 'nova::migration::libvirt' do
       }).that_requires('Package[libvirt]').that_notifies('Service[libvirt]') }
     end
 
+    context 'with override_uuid enabled and host_uuid set' do
+      let :params do
+        {
+          :override_uuid => true,
+          :host_uuid => 'a8debd9d-e359-4bb2-8c77-edee431f94f2',
+        }
+      end
+
+      it { is_expected.to contain_file('/etc/libvirt/libvirt_uuid').with({
+        :content => 'a8debd9d-e359-4bb2-8c77-edee431f94f2',
+      }).that_requires('Package[libvirt]') }
+
+      it { is_expected.to contain_augeas('libvirt-conf-uuid').with({
+        :context => '/files/etc/libvirt/libvirtd.conf',
+        :changes => [ "set host_uuid a8debd9d-e359-4bb2-8c77-edee431f94f2" ],
+      }).that_requires('Package[libvirt]').that_notifies('Service[libvirt]') }
+    end
+
     context 'with tls enabled' do
       let :params do
         {