Deprecate memcached_servers parameter

It is 'memcache_servers' in group [cache], not 'memcached_servers'.
For better understanding, deprecate memcached_servers option and
use memcahce_servers instead.

Change-Id: I57d7b45438904387176200c0062b7f33f4268006
Closes-Bug: #1690981

manifests/init.pp

@@ -138,7 +138,7 @@
 #   (string value)
 #   Defaults to $::os_service_default
 #
-# [*memcached_servers*]
+# [*memcache_servers*]
 #   (Optional) A list of memcached server(s) to use for caching. (list value)
 #   Defaults to $::os_service_default
 #
@@ -253,6 +253,10 @@
 #   (Optional) The RabbitMQ virtual host. (string value)
 #   Defaults to $::os_service_default
 #
+# [*memcached_servers*]
+#   (Optional) A list of memcached server(s) to use for caching. (list value)
+#   Defaults to $::os_service_default
+#
 class ceilometer(
   $http_timeout                       = '600',
   $event_time_to_live                 = '-1',
@@ -282,7 +286,7 @@ class ceilometer(
   $kombu_ssl_version                  = $::os_service_default,
   $kombu_reconnect_delay              = $::os_service_default,
   $kombu_compression                  = $::os_service_default,
-  $memcached_servers                  = $::os_service_default,
+  $memcache_servers                   = $::os_service_default,
   $amqp_server_request_prefix         = $::os_service_default,
   $amqp_broadcast_prefix              = $::os_service_default,
   $amqp_group_request_prefix          = $::os_service_default,
@@ -311,6 +315,7 @@ class ceilometer(
   $rabbit_userid                      = $::os_service_default,
   $rabbit_password                    = $::os_service_default,
   $rabbit_virtual_host                = $::os_service_default,
+  $memcached_servers                  = undef,
 ) {
 
   include ::ceilometer::deps
@@ -346,6 +351,15 @@ ceilometer::rabbit_port, ceilometer::rabbit_userid and ceilometer::rabbit_virtua
 deprecated. Please use ceilometer::default_transport_url instead.")
   }
 
+  if $memcached_servers {
+    warning("memcached_servers parameter is deprecated and will be removed in the future release, \
+please use memcache_servers instead.")
+    $memcache_servers_real = $memcached_servers
+  }
+  else {
+    $memcache_servers_real = $memcache_servers
+  }
+
   group { 'ceilometer':
     name    => 'ceilometer',
     require => Anchor['ceilometer::install::end'],
@@ -435,6 +449,6 @@ deprecated. Please use ceilometer::default_transport_url instead.")
   }
 
   oslo::cache { 'ceilometer_config':
-    memcache_servers => $memcached_servers,
+    memcache_servers => $memcache_servers_real,
   }
 }

releasenotes/notes/deprecate_memcached_servers-819a35d8991621f7.yaml

@@ -0,0 +1,4 @@
+---
+deprecations:
+  - memcached_servers option is now deprecated and will be removed in
+    the future release, please use memcache_servers instead.

spec/classes/ceilometer_init_spec.rb

@@ -4,24 +4,24 @@ describe 'ceilometer' do
 
   let :params do
     {
-      :http_timeout               => '600',
+      :http_timeout          => '600',
-      :event_time_to_live         => '604800',
+      :event_time_to_live    => '604800',
-      :metering_time_to_live      => '604800',
+      :metering_time_to_live => '604800',
-      :telemetry_secret           => 'metering-s3cr3t',
+      :telemetry_secret      => 'metering-s3cr3t',
-      :package_ensure             => 'present',
+      :package_ensure        => 'present',
-      :debug                      => 'False',
+      :debug                 => 'False',
-      :log_dir                    => '/var/log/ceilometer',
+      :log_dir               => '/var/log/ceilometer',
-      :use_stderr                 => 'True',
+      :use_stderr            => 'True',
-      :purge_config               => false,
+      :purge_config          => false,
     }
   end
 
   let :rabbit_params do
     {
-      :rabbit_host        => '127.0.0.1',
+      :rabbit_host     => '127.0.0.1',
-      :rabbit_port        => 5672,
+      :rabbit_port     => 5672,
-      :rabbit_userid      => 'guest',
+      :rabbit_userid   => 'guest',
-      :rabbit_password    => '',
+      :rabbit_password => '',
     }
   end
 
@@ -139,6 +139,10 @@ describe 'ceilometer' do
       is_expected.to contain_ceilometer_config('hardware/readonly_user_password').with_value('<SERVICE DEFAULT>')
     end
 
+    it 'configures cache backend' do
+      is_expected.to contain_ceilometer_config('cache/memcache_servers').with_value('<SERVICE DEFAULT>')
+    end
+
     context 'with rabbitmq durable queues configured' do
       before { params.merge!( :amqp_durable_queues => true ) }
       it_configures 'rabbit with durable queues'
@@ -160,6 +164,18 @@ describe 'ceilometer' do
       end
     end
 
+    context 'with overriden cache parameter' do
+      before {
+        params.merge!(
+          :memcache_servers => 'host1:11211,host2:11211',
+        )
+      }
+
+      it 'configures cache backend' do
+        is_expected.to contain_ceilometer_config('cache/memcache_servers').with_value('host1:11211,host2:11211')
+      end
+    end
+
     context 'with overriden notification parameters' do
       before {
         params.merge!(