Adds support for RabbitMQ Clustering

Prior to this change, only a single RabbitMQ Broker
could be deployed by the nova::rabbitmq class.

This change implements the cluster_disk_nodes parameter
that can enable RabbitMQ clustering.

Defaults to false for backwards compatibility.

Change-Id: Iac2d04e855adb53fbb9fe2a23f8773a692162744

manifests/rabbitmq.pp

@@ -2,12 +2,19 @@
 # class for installing rabbitmq server for nova
 #
 #
+# ==Parameters
+#
+# [cluster_disk_nodes] Enables/disables RabbitMQ clustering.  Specify an array of Rabbit Broker
+#   IP addresses to configure clustering. Optional.
+#   Defaults to false.
+#
 class nova::rabbitmq(
-  $userid       ='guest',
-  $password     ='guest',
-  $port         ='5672',
-  $virtual_host ='/',
-  $enabled      = true
+  $userid             ='guest',
+  $password           ='guest',
+  $port               ='5672',
+  $virtual_host       ='/',
+  $cluster_disk_nodes = false,
+  $enabled            = true
 ) {
 
   # only configure nova after the queue is up
@@ -37,10 +44,21 @@ class nova::rabbitmq(
     $service_ensure = 'stopped'
   }
 
-  class { 'rabbitmq::server':
-    service_ensure    => $service_ensure,
-    port              => $port,
-    delete_guest_user => $delete_guest_user,
+  if $cluster_disk_nodes {
+    class { 'rabbitmq::server':
+      service_ensure           => $service_ensure,
+      port                     => $port,
+      delete_guest_user        => $delete_guest_user,
+      config_cluster           => true,
+      cluster_disk_nodes       => $cluster_disk_nodes,
+      wipe_db_on_cookie_change => true,
+    }
+  } else {
+    class { 'rabbitmq::server':
+      service_ensure    => $service_ensure,
+      port              => $port,
+      delete_guest_user => $delete_guest_user,
+    }
   }
 
   if ($enabled) {

spec/classes/nova_rabbitmq_spec.rb

@@ -75,5 +75,28 @@ describe 'nova::rabbitmq' do
     end
   end
 
+  describe 'with clustering' do
+
+    let :params do
+      {
+        :cluster_disk_nodes => ['rabbit01', 'rabbit02', 'rabbit03']
+      }
+    end
+
+    it 'should contain all the clustering resources' do
+
+      should contain_class('rabbitmq::server').with(
+        :service_ensure           => 'running',
+        :port                     => '5672',
+        :delete_guest_user        => false,
+        :config_cluster           => true,
+        :cluster_disk_nodes       => ['rabbit01', 'rabbit02', 'rabbit03'],
+        :wipe_db_on_cookie_change => true
+      )
+
+    end
+
+  end
+
 
 end