Use this in wp-config to be able to run the blog both locally and deployed on AppFog.

wp-config.php

$services = getenv("VCAP_SERVICES");

if ( $services != null){
  $services_json = json_decode($services,true);
  $mysql_config = $services_json["mysql-5.1"][0]["credentials"];
  define('DB_NAME', $mysql_config["name"]);
  define('DB_USER', $mysql_config["user"]);
  define('DB_PASSWORD', $mysql_config["password"]);
  define('DB_HOST', $mysql_config["hostname"]);
  define('DB_PORT', $mysql_config["port"]);
}
else{
  define('DB_NAME', "localdb");
  define('DB_USER', "root");
  define('DB_PASSWORD', "password");
  define('DB_HOST', "localhost");
  define('DB_PORT', 8889); 
}