Have statsd listen on ipv6 by default

By default we're not listening on an ipv6 address; so any stats sent
there just go missing.  Set up by default to listen to '::' (and add
required ipv6 argument) which, thanks to dual-stack, means ipv4 & 6
packets are all accounted for.

Change-Id: I1fec03b32441a1962190f9bd8e24e8bec2318ab5

manifests/init.pp

@@ -22,6 +22,9 @@ class graphite(
     }
   ],
   $vhost_name      = $::fqdn,
+  # Have statsd listen on '::' which, thanks to dual-stack,
+  # gets ipv4 and ipv6 connections.
+  $statsd_ipv6_listen = true,
 ) {
   $packages = [ 'python-django',
                 'python-django-tagging',

spec/acceptance/basic_spec.rb

@@ -80,6 +80,8 @@ describe 'puppet-graphite module', :if => ['debian', 'ubuntu'].include?(os[:fami
       it { should be_owned_by 'statsd' }
       it { should be_grouped_into 'statsd' }
       its(:content) { should include 'graphitePort: 2003' }
+      its(:content) { should include "address: '::'" }
+
     end
 
     describe file('/etc/graphite/carbon.conf') do

templates/config.js.erb

@@ -56,4 +56,8 @@ Optional Variables:
 , port: 8125
 , deleteTimers: true
 , deleteCounters: true
+<% if @statsd_ipv6_listen %>
+, address: '::',
+, address_ipv6: true
+<% end %>
 }