Respect DISALLOW_FILE_MODS, but why?

[vreoo]

Hello there,

In your recent 2.5.0 update, we noticed that you added this change: df87cc2

/**
     * Determines whether object cache file modifications are allowed.
     *
     * @return bool
     */
    function is_file_mod_allowed() {
        return apply_filters(
            'file_mod_allowed',
            ! defined( 'DISALLOW_FILE_MODS' ) || ! DISALLOW_FILE_MODS,
            'object_cache_dropin'
        );
    }

And this:

 if ( ! $this->is_file_mod_allowed() ) {
            return new WP_Error( 'disallowed', __( 'File modifications are not allowed.', 'redis-cache' ) );
        }

But I don't fully get it, what is the reason behind this change?

We have DISALLOW_FILE_MODS set to true on our environment so when we updated your plugin it started to give us a not writable error so we had to manually ignore DISALLOW_FILE_MODS for the redis object cache by adding a function to functions.php so we can make the plugin work again.

What is the best practice here in our case in your opinion? how will that affect the environment?

Thanks,

[tillkruss]

Those are essentially checks for wp_is_file_mod_allowed().

If the filesystem is not writeable (DISALLOW_FILE_MODS = true) then we shouldn't try to write the drop-in on the filesystem.

In your environment, I'd suggest putting the object-cache.php in place by hand, or using WP CLI.