memcached: better default configuration

memcached/README.md

@@ -10,10 +10,10 @@ Minimal configuration is in `tasks/main.yml`
 
 Main variables are :
 
-* `memcached_logfile`: path of the log file ;
-* `memcached_mem`: amount of memory ;
-* `memcached_user`: running user ;
-* `memcached_bind_interface`: interface to listen to ;
-* `memcached_connections`: number of simultaneous incoming connections ;
+* `memcached_mem`: amount of memory (default: `64`) ;
+* `memcached_user`: running user (default: `nobody`) ;
+* `memcached_port`: opened port (default: `11211`) ;
+* `memcached_bind_interface`: interface to listen to (default: `127.0.0.1`) ;
+* `memcached_connections`: number of simultaneous incoming connections (default: `1024`) ;
 
 The full list of variables (with default values) can be found in `defaults/main.yml`.

memcached/defaults/main.yml

@@ -2,6 +2,6 @@
 memcached_logfile: '/var/log/memcached.log'
 memcached_mem: 64
 memcached_user: 'nobody'
-memcached_bind_interface: '0.0.0.0'
+memcached_bind_interface: '127.0.0.1'
 memcached_connections: 1024
-
+memcached_port: 11211

memcached/templates/memcached.conf.j2

@@ -1,6 +1,47 @@
+# memcached default config file
+# 2003 - Jay Bonci <jaybonci@debian.org>
+# This configuration file is read by the start-memcached script provided as
+# part of the Debian GNU/Linux distribution.
+
+# Run memcached as a daemon. This command is implied, and is not needed for the
+# daemon to run. See the README.Debian that comes with this package for more
+# information.
 -d
-logfile {{ memcached_logfile }}
--m {{ memcached_mem }}
--u {{ memcached_user }}
--l {{ memcached_bind_interface }}
--c {{ memcached_connections }}
+
+# Log memcached's output to /var/log/memcached
+logfile {{ memcached_logfile | mandatory }}
+
+# Be verbose
+# -v
+
+# Be even more verbose (print client commands as well)
+# -vv
+
+# Start with a cap of 64 megs of memory. It's reasonable, and the daemon default
+# Note that the daemon will grow to this size, but does not start out holding this much
+# memory
+-m {{ memcached_mem | mandatory }}
+
+# Default connection port is 11211
+-p {{ memcached_port | mandatory }}
+
+# Run the daemon as root. The start-memcached will default to running as root if no
+# -u command is present in this config file
+-u {{ memcached_user | mandatory }}
+
+# Specify which IP address to listen on. The default is to listen on all IP addresses
+# This parameter is one of the only security measures that memcached has, so make sure
+# it's listening on a firewalled interface.
+-l {{ memcached_bind_interface | mandatory }}
+
+# Limit the number of simultaneous incoming connections. The daemon default is 1024
+-c {{ memcached_connections | mandatory }}
+
+# Lock down all paged memory. Consult with the README and homepage before you do this
+# -k
+
+# Return error when memory is exhausted (rather than removing items)
+# -M
+
+# Maximize core file limit
+# -r