example.settings.php

<?php

/**
 * Salt for one-time login links, cancel links, form tokens, etc.
 *
 * This variable will be set to a random value by the installer. All one-time
 * login links will be invalidated if the value is changed. Note that if your
 * site is deployed on a cluster of web servers, you must ensure that this
 * variable has the same value on each server.
 *
 * For enhanced security, you may set this variable to the contents of a file
 * outside your document root, and vary the value across environments (like
 * production and development); you should also ensure that this file is not
 * stored with backups of your database.
 *
 * Example:
 * @code
 *   $settings['hash_salt'] = file_get_contents('/home/example/salt.txt');
 * @endcode
 */
$settings['hash_salt'] = getenv('DRUPAL_HASH_SALT');

/**
 * Database settings:
 *
 * The $databases array specifies the database connection or
 * connections that Drupal may use.  Drupal is able to connect
 * to multiple databases, including multiple types of databases,
 * during the same request.
 *
 * One example of the simplest connection array is shown below. To use the
 * sample settings, copy and uncomment the code below between the @code and
 * @endcode lines and paste it after the $databases declaration. You will need
 * to replace the database username and password and possibly the host and port
 * with the appropriate credentials for your database system.
 *
 * The next section describes how to customize the $databases array for more
 * specific needs.
 *
 * @code
 * $databases['default']['default'] = [
 *   'database' => 'databasename',
 *   'username' => 'sql_username',
 *   'password' => 'sql_password',
 *   'host' => 'localhost',
 *   'port' => '3306',
 *   'driver' => 'mysql',
 *   'prefix' => '',
 *   'collation' => 'utf8mb4_general_ci',
 * ];
 * @endcode
 */
$databases['default']['default'] = [
  'database' => getenv('MYSQL_DATABASE'),
  'username' => getenv('MYSQL_USER'),
  'password' => getenv('MYSQL_PASSWORD'),
  'host' => getenv('MYSQL_HOST'),
  'port' => getenv('MYSQL_PORT'),
  'driver' => 'mysql',
  'prefix' => '',
  'collation' => 'utf8mb4_unicode_ci',
];

/**
 * Access control for update.php script.
 *
 * If you are updating your Drupal installation using the update.php script but
 * are not logged in using either an account with the "Administer software
 * updates" permission or the site maintenance account (the account that was
 * created during installation), you will need to modify the access check
 * statement below. Change the FALSE to a TRUE to disable the access check.
 * After finishing the upgrade, be sure to open this file again and change the
 * TRUE back to a FALSE!
 */
$settings['update_free_access'] = FALSE;

/**
 * Reverse Proxy Configuration:
 *
 * Reverse proxy servers are often used to enhance the performance
 * of heavily visited sites and may also provide other site caching,
 * security, or encryption benefits. In an environment where Drupal
 * is behind a reverse proxy, the real IP address of the client should
 * be determined such that the correct client IP address is available
 * to Drupal's logging, statistics, and access management systems. In
 * the most simple scenario, the proxy server will add an
 * X-Forwarded-For header to the request that contains the client IP
 * address. However, HTTP headers are vulnerable to spoofing, where a
 * malicious client could bypass restrictions by setting the
 * X-Forwarded-For header directly. Therefore, Drupal's proxy
 * configuration requires the IP addresses of all remote proxies to be
 * specified in $settings['reverse_proxy_addresses'] to work correctly.
 *
 * Enable this setting to get Drupal to determine the client IP from the
 * X-Forwarded-For header. If you are unsure about this setting, do not have a
 * reverse proxy, or Drupal operates in a shared hosting environment, this
 * setting should remain commented out.
 *
 * In order for this setting to be used you must specify every possible
 * reverse proxy IP address in $settings['reverse_proxy_addresses'].
 * If a complete list of reverse proxies is not available in your
 * environment (for example, if you use a CDN) you may set the
 * $_SERVER['REMOTE_ADDR'] variable directly in settings.php.
 * Be aware, however, that it is likely that this would allow IP
 * address spoofing unless more advanced precautions are taken.
 */
$settings['reverse_proxy'] = TRUE;

/**
 * Reverse proxy addresses.
 *
 * Specify every reverse proxy IP address in your environment, as an array of
 * IPv4/IPv6 addresses or subnets in CIDR notation. This setting is required if
 * $settings['reverse_proxy'] is TRUE.
 */
 $settings['reverse_proxy_addresses'] = [@$_SERVER['REMOTE_ADDR']];

/**
 * Load services definition file.
 */
$settings['container_yamls'][] = $app_root . '/' . $site_path . '/services.yml';

/**
 * Trusted host configuration.
 *
 * Drupal core can use the Symfony trusted host mechanism to prevent HTTP Host
 * header spoofing.
 *
 * To enable the trusted host mechanism, you enable your allowable hosts
 * in $settings['trusted_host_patterns']. This should be an array of regular
 * expression patterns, without delimiters, representing the hosts you would
 * like to allow.
 *
 * For example:
 * @code
 * $settings['trusted_host_patterns'] = [
 *   '^www\.example\.com$',
 * ];
 * @endcode
 * will allow the site to only run from www.example.com.
 *
 * If you are running multisite, or if you are running your site from
 * different domain names (eg, you don't redirect http://www.example.com to
 * http://example.com), you should specify all of the host patterns that are
 * allowed by your site.
 *
 * For example:
 * @code
 * $settings['trusted_host_patterns'] = [
 *   '^example\.com$',
 *   '^.+\.example\.com$',
 *   '^example\.org$',
 *   '^.+\.example\.org$',
 * ];
 * @endcode
 * will allow the site to run off of all variants of example.com and
 * example.org, with all subdomains included.
 *
 * @see https://www.drupal.org/docs/installing-drupal/trusted-host-settings
 */
$settings['trusted_host_patterns'] = [
];

/**
 * The default list of directories that will be ignored by Drupal's file API.
 *
 * By default ignore node_modules and bower_components folders to avoid issues
 * with common frontend tools and recursive scanning of directories looking for
 * extensions.
 *
 * @see \Drupal\Core\File\FileSystemInterface::scanDirectory()
 * @see \Drupal\Core\Extension\ExtensionDiscovery::scanDirectory()
 */
$settings['file_scan_ignore_directories'] = [
  'node_modules',
  'bower_components',
];

/**
 * The default number of entities to update in a batch process.
 *
 * This is used by update and post-update functions that need to go through and
 * change all the entities on a site, so it is useful to increase this number
 * if your hosting configuration (i.e. RAM allocation, CPU speed) allows for a
 * larger number of entities to be processed in a single batch run.
 */
$settings['entity_update_batch_size'] = 50;

/**
 * Entity update backup.
 *
 * This is used to inform the entity storage handler that the backup tables as
 * well as the original entity type and field storage definitions should be
 * retained after a successful entity update process.
 */
$settings['entity_update_backup'] = TRUE;

/**
 * Node migration type.
 *
 * This is used to force the migration system to use the classic node migrations
 * instead of the default complete node migrations. The migration system will
 * use the classic node migration only if there are existing migrate_map tables
 * for the classic node migrations and they contain data. These tables may not
 * exist if you are developing custom migrations and do not want to use the
 * complete node migrations. Set this to TRUE to force the use of the classic
 * node migrations.
 */
$settings['migrate_node_migrate_type_classic'] = FALSE;

/**
 * Location of the site configuration files.
 *
 * The $settings['config_sync_directory'] specifies the location of file system
 * directory used for syncing configuration data. On install, the directory is
 * created. This is used for configuration imports.
 *
 * The default location for this directory is inside a randomly-named
 * directory in the public files path. The setting below allows you to set
 * its location.
 */
$settings['config_sync_directory'] = dirname($app_root) . '/config';

/**
 * State caching.
 *
 * State caching uses the cache collector pattern to cache all requested keys
 * from the state API in a single cache entry, which can greatly reduce the
 * amount of database queries. However, some sites may use state with a
 * lot of dynamic keys which could result in a very large cache.
 */
$settings['state_cache'] = TRUE;

/**
 * Load local development override configuration, if available.
 *
 * Create a settings.local.php file to override variables on secondary (staging,
 * development, etc.) installations of this site.
 *
 * Typical uses of settings.local.php include:
 * - Disabling caching.
 * - Disabling JavaScript/CSS compression.
 * - Rerouting outgoing emails.
 *
 * Keep this code block at the end of this file to take full effect.
 */
if (file_exists($app_root . '/' . $site_path . '/settings.local.php')) {
  include $app_root . '/' . $site_path . '/settings.local.php';
}