Adds Support for Separating Memcached from Horizon

Previously, memcached would always be included in the
openstack::horizon class.  Additionally, the cache_server_ip
parameter was used concurrently by memcached and horizon classes.
This prevented users from 1. Using an existing memcached deployment
2. Binding memcached to a local address and having
Horizon use an external memcached server.

This change implements the configure_memcached and memcached_listen_ip
parameters.  configure_memcached allows users to enable/disable
the memcached class on an as-needed basis.  memcached_listen_ip allows
users to seperate the IP address used for binding memcached from the
address used by Horizon to access memcached.

configure_memcached defaults to 'true' and memcached_listen_ip
defaults to undef for backwards compatibility and to enable memcached
and have memcached use cache_server_ip for binding an IP.

Change-Id: I5e4f4b5786d5ce7da59004a6a55b675a6dd32541

manifests/horizon.pp

@@ -14,6 +14,14 @@
 #   (required) A secret key for a particular Django installation. This is used to provide cryptographic signing,
 #   and should be set to a unique, unpredictable value.
 #
+# [*configure_memcached*]
+#   (optional) Enable/disable the use of memcached with Horizon.
+#   Defaults to true.
+#
+# [*memcached_listen_ip*]
+#   (optional) The IP address for binding memcached.
+#   Defaults to undef.
+#
 # [*cache_server_ip*]
 #   (optional) Ip address where the memcache server is listening.
 #   Defaults to '127.0.0.1'.
@@ -55,6 +63,8 @@
 
 class openstack::horizon (
   $secret_key,
+  $configure_memcached   = true,
+  $memcached_listen_ip   = undef,
   $cache_server_ip       = '127.0.0.1',
   $cache_server_port     = '11211',
   $horizon_app_links     = undef,
@@ -65,10 +75,18 @@ class openstack::horizon (
   $api_result_limit      = 1000
 ) {
 
-  class { 'memcached':
+  if $configure_memcached {
-    listen_ip => $cache_server_ip,
+    if $memcached_listen_ip {
-    tcp_port  => $cache_server_port,
+      $cache_server_ip_real = $memcached_listen_ip
-    udp_port  => $cache_server_port,
+    } else {
+      warning('The cache_server_ip parameter is deprecated. Use memcached_listen_ip instead.')
+      $cache_server_ip_real = $cache_server_ip
+    }
+    class { 'memcached':
+      listen_ip => $cache_server_ip_real,
+      tcp_port  => $cache_server_port,
+      udp_port  => $cache_server_port,
+    }
   }
 
   class { '::horizon':

spec/classes/openstack_horizon_spec.rb

@@ -39,4 +39,39 @@ describe 'openstack::horizon' do
     )
   end
 
+  context 'when memcached is disabled' do
+    let :params do
+      required_params.merge(
+        :configure_memcached => false
+      )
+    end
+    it 'should configure horizon without memcached using default parameters and secret key' do
+      should_not contain_class('memcached')
+      should contain_class('horizon').with(
+        :cache_server_ip       => '127.0.0.1',
+        :cache_server_port     => '11211',
+        :secret_key            => 'super_secret',
+        :horizon_app_links     => false,
+        :keystone_host         => '127.0.0.1',
+        :keystone_scheme       => 'http',
+        :keystone_default_role => 'Member',
+        :django_debug          => 'False',
+        :api_result_limit      => 1000
+      )
+    end
+  end
+
+  context 'when memcached listen ip is overridden' do
+    let :params do
+      required_params.merge(
+        :configure_memcached => true,
+        :memcached_listen_ip => '10.10.10.10'
+      )
+    end
+    it 'should override params for memcached' do
+      should contain_class('memcached').with(
+        :listen_ip => '10.10.10.10'
+      )
+    end
+  end
 end