Add maxmemory-policy configurable

This patch makes the redis maxmemory-policy configurable,
and sets default value to allkeys-lru instead of
volatile-lru. The setting allkeys-lru helps to remove keys
without an exact expire setting of a keypair.

Change-Id: I5edaa6a5fbdc99631838478460b36795539292cf

manifests/init.pp

@@ -21,6 +21,7 @@ class redis(
   $redis_bind = '127.0.0.1',
   $redis_password = '',
   $redis_max_memory = '1gb',
+  $redis_max_memory_policy = 'allkeys-lru',
   $version = '2.2.12',
 ) {
 

templates/redis.2.2.conf.erb

@@ -218,6 +218,7 @@ maxmemory <%= redis_max_memory %>
 # The default is:
 #
 # maxmemory-policy volatile-lru
+maxmemory-policy <%= @redis_max_memory_policy %>
 
 # LRU and minimal TTL algorithms are not precise algorithms but approximated
 # algorithms (in order to save memory), so you can select as well the sample

templates/redis.2.4.conf.erb

@@ -254,6 +254,7 @@ maxmemory <%= redis_max_memory %>
 # The default is:
 #
 # maxmemory-policy volatile-lru
+maxmemory-policy <%= @redis_max_memory_policy %>
 
 # LRU and minimal TTL algorithms are not precise algorithms but approximated
 # algorithms (in order to save memory), so you can select as well the sample

templates/redis.2.6.conf.erb

@@ -338,6 +338,7 @@ maxmemory <%= redis_max_memory %>
 # The default is:
 #
 # maxmemory-policy volatile-lru
+maxmemory-policy <%= @redis_max_memory_policy %>
 
 # LRU and minimal TTL algorithms are not precise algorithms but approximated
 # algorithms (in order to save memory), so you can select as well the sample