Make ES Heap Size configurable.

wiki.o.o is much smaller than our typical elasticsearch nodes. For it to
use elasticsearch it needs to allocate a much smaller heap. Make the
heap size configurable (keep the 16g default) and set the heap size to
1g for wiki.o.o.

Change-Id: I0c5fb4865eb07c0fa5bbe4cf698a9f0e9ea9f2fc

modules/elasticsearch/manifests/init.pp

@@ -16,7 +16,8 @@
 #
 class elasticsearch (
   $discover_nodes = ['localhost'],
-  $version = '0.20.5'
+  $version = '0.20.5',
+  $heap_size = '16g'
 ) {
   # install java runtime
   package { 'java7-runtime-headless':
@@ -96,7 +97,7 @@ class elasticsearch (
 
   file { '/etc/default/elasticsearch':
     ensure  => present,
-    source  => 'puppet:///modules/elasticsearch/elasticsearch.default',
+    content => template('elasticsearch/elasticsearch.default.erb'),
     replace => true,
     owner   => 'root',
     group   => 'root',

modules/elasticsearch/templates/elasticsearch.default.erb

@@ -3,7 +3,7 @@
 #ES_GROUP=elasticsearch
 
 # Heap Size (defaults to 256m min, 1g max)
-ES_HEAP_SIZE=16g
+ES_HEAP_SIZE=<%= heap_size %>
 
 # Heap new generation
 #ES_HEAP_NEWSIZE=

modules/openstack_project/manifests/wiki.pp

@@ -60,6 +60,7 @@ class openstack_project::wiki (
   class { '::elasticsearch':
     discover_nodes => ['localhost'],
     version        => '0.90.5',
+    heap_size      => '1g',
   }
 
 }