Stage-specific Drupal settings with local_settings.php

The decision to store settings.php in your version control system can be sticky. On one hand, there may be application-specific settings you would like to manage (perhaps the session lifetime, for example). On the other hand, it's a bad practice to store passwords in VCS, and some settings are host-specific. Perhaps you'd like to disable CSS aggregation on your development stage, or enable memcached only on your production stage.

Here is how I approach the problem:
I create a second config file, local_settings.php. Then I configure it to override anything in the main settings file by adding this to settings.php:

if (file_exists('./'. conf_path() .'/local_settings.php')) {
  include_once './'. conf_path() .'/local_settings.php';
}

settings.php is placed in version control, and local_settings.php is not. Upon deployment, the local settings file is then symlinked to a shared directory in each server.

Here are some ideas for your own local_settings.php file:

// Database settings
$db_url = 'mysqli://drupal:12345@localhost/drupal';
$db_prefix = '';
 
// Bypass almost all Drupal caches
$conf['cache_inc'] = 'includes/cache-install.inc';
 
// Page cache
$conf['cache'] = CACHE_DISABLED;
 
// Block cache
$conf['block_cache'] = CACHE_DISABLED;
 
// Optimize CSS files
$conf['preprocess_css'] = CACHE_DISABLED;
 
// Optimize JavaScript files
$conf['preprocess_js'] = CACHE_DISABLED;