Give Redis write permissions when DISALLOW_FILE_MODS is enabled in WordPress

redis-write-permissions.php

<?php 

/**
 * Class Redis_Write_Permissions
 *
 * This class is responsible for enabling write permissions for the Redis object cache drop-in
 * when the DISALLOW_FILE_MODS constant is set to true, without having to disable DISALLOW_FILE_MODS.
 * 
 * Notes:         Use with https://wordpress.org/plugins/redis-cache/ (Redis Object Cache by Till Krüss)
 *                By default, the Redis Object Cache drop-in is not writeable when DISALLOW_FILE_MODS is set to true.
 * 
 * Installation:  Create a new file in the mu-plugins folder called redis-write-permissions.php
 *                If you do not have a mu-plugins folder you can create one in the wp-content folder.
 *                Copy all of this and paste it into redis-write-permissions.php
 *                No activation is needed and the plugin will work immediately.
 *                Verify in the Redis Object Cache plugin settings that the filesystem is writeable.
 * 
 * Thanks to:     Edgards Abolins for providing the original solution (https://doinwp.com/tips/fix-for-redis-filesystem-not-writeable/).
 *                Till Krüss for providing the Redis Object Cache plugin.
 *                Templ.io for excellent managed WordPress hosting and support.
 * 
 * Author: Daniel Leis 
 * Version: 1.0
 */
class Redis_Write_Permissions {

  /**
   * Constructor method.
   * It checks if DISALLOW_FILE_MODS is set and true, and if so, enables write permissions for the Redis object cache drop-in.
   */
  public function __construct() {
    if (defined('DISALLOW_FILE_MODS') && DISALLOW_FILE_MODS) {
      add_filter('file_mod_allowed', array($this, 'enable_redis_dropin_write_permissions'), 10, 2);
    }
  }

  /**
   * Enables Redis drop-in write permissions.
   *
   * This function checks if the provided context is 'object_cache_dropin'.
   * If the context matches, it returns true, otherwise it returns the provided setting.
   *
   * @param mixed $setting The original setting value.
   * @param string $context The context in which the setting is being checked.
   * @return bool The updated setting value.
  */
  public function enable_redis_dropin_write_permissions(bool $setting, string $context) {
    return in_array($context, ['object_cache_dropin']) ? true : $setting;
  }
}

new Redis_Write_Permissions();