Add support for configuring coordination/backend_url

If 'coordination_url' argument and value is provided to the central agent
or alarm evaluator classes, they will try to set 'backend_url' in the
'[coordination]' section of the ceilometer_config. This allows group
membership handling coordinated by tooz.

ensure_resource is used to avoid duplicate resources while still allowing
the central agent and alarm evaluator to be configured separately if
on different machines.

Note that this change does not include support for enabling coordination
of the compute agent.

Change-Id: I707a8b70ad742cc9f8fdc62c196d0e75574a50b2
(cherry picked from commit fade72d)

manifests/agent/central.pp

@@ -13,11 +13,16 @@
 #    (optional) ensure state for package.
 #    Defaults to 'present'
 #
+#  [*coordination_url*]
+#    (optional) The url to use for distributed group membership coordination.
+#    Defaults to undef.
+#
 
 class ceilometer::agent::central (
   $manage_service   = true,
   $enabled          = true,
   $package_ensure   = 'present',
+  $coordination_url = undef,
 ) {
 
   include ceilometer::params
@@ -47,4 +52,8 @@
     hasrestart => true,
   }
 
+  if $coordination_url {
+    ensure_resource('ceilometer_config', 'coordination/backend_url',
+      {'value' => $coordination_url})
+  }
 }

manifests/alarm/evaluator.pp

@@ -25,13 +25,18 @@
 #    (optional) Record alarm change events
 #    Defaults to true.
 #
+#  [*coordination_url*]
+#    (optional) The url to use for distributed group membership coordination.
+#    Defaults to undef.
+#
 class ceilometer::alarm::evaluator (
   $manage_service      = true,
   $enabled             = true,
   $evaluation_interval = 60,
   $evaluation_service  = 'ceilometer.alarm.service.SingletonAlarmService',
   $partition_rpc_topic = 'alarm_partition_coordination',
   $record_history      = true,
+  $coordination_url    = undef,
 ) {
 
   include ceilometer::params
@@ -67,5 +72,10 @@
     'alarm/evaluation_service'  :  value => $evaluation_service;
     'alarm/partition_rpc_topic' :  value => $partition_rpc_topic;
     'alarm/record_history'      :  value => $record_history;
-    }
+  }
+
+  if $coordination_url {
+    ensure_resource('ceilometer_config', 'coordination/backend_url',
+      {'value' => $coordination_url})
+  }
 }

spec/classes/ceilometer_agent_central_spec.rb

@@ -7,9 +7,11 @@
   end
 
   let :params do
-    { :enabled        => true,
-      :manage_service => true,
-      :package_ensure => 'latest' }
+    { :enabled          => true,
+      :manage_service   => true,
+      :package_ensure   => 'latest',
+      :coordination_url => 'redis://localhost:6379'
+    }
   end
 
   shared_examples_for 'ceilometer-agent-central' do
@@ -48,6 +50,10 @@
       end
     end
 
+    it 'configures central agent' do
+      should contain_ceilometer_config('coordination/backend_url').with_value( params[:coordination_url] )
+    end
+
     context 'with disabled service managing' do
       before do
         params.merge!({

spec/classes/ceilometer_alarm_evaluator_spec.rb

@@ -38,19 +38,22 @@
       should contain_ceilometer_config('alarm/evaluation_service').with_value( params[:evaluation_service] )
       should contain_ceilometer_config('alarm/partition_rpc_topic').with_value( params[:partition_rpc_topic] )
       should contain_ceilometer_config('alarm/record_history').with_value( params[:record_history] )
+      should_not contain_ceilometer_config('coordination/backend_url')
     end
 
     context 'when overriding parameters' do
       before do
         params.merge!(:evaluation_interval => 80,
                       :partition_rpc_topic => 'alarm_partition_coordination',
                       :record_history      => false,
-                      :evaluation_service  => 'ceilometer.alarm.service.SingletonTestAlarmService')
+                      :evaluation_service  => 'ceilometer.alarm.service.SingletonTestAlarmService',
+                      :coordination_url     => 'redis://localhost:6379')
       end
       it { should contain_ceilometer_config('alarm/evaluation_interval').with_value(params[:evaluation_interval]) }
       it { should contain_ceilometer_config('alarm/evaluation_service').with_value(params[:evaluation_service]) }
       it { should contain_ceilometer_config('alarm/record_history').with_value(params[:record_history]) }
       it { should contain_ceilometer_config('alarm/partition_rpc_topic').with_value(params[:partition_rpc_topic])  }
+      it { should contain_ceilometer_config('coordination/backend_url').with_value( params[:coordination_url]) }
     end
 
     context 'when override the evaluation interval with a non numeric value' do