XF 2.2 Config.php to use multiple cdns

[Goose]

Hi, I would need to know if there is a way to configure the XF config to use multiple cdn to load the attached files.
I would like one of the links to be taken randomly, I don't care about a precise balance.
Is it possible somehow?
This is an example:
$config['externalDataUrl'] = 'https://cdn1.XXXX.XXX/forums/data';
$config['externalDataUrl'] = 'https://cdn2.XXXX.XXX/forums/data';
$config['externalDataUrl'] = 'https://cdn3.XXXX.XXX/forums/data';

Thanks

 

[benFF]

$cdnArray = ['https://cdn1.XXXX.XXX/forums/data', 'https://cdn2.XXXX.XXX/forums/data', 'https://cdn3.XXXX.XXX/forums/data'];
$config['externalDataUrl'] = $cdnArray[array_rand($cdnArray)];

 

[Kirby]

$cdnArray = ['https://cdn1.XXXX.XXX/forums/data', 'https://cdn2.XXXX.XXX/forums/data', 'https://cdn3.XXXX.XXX/forums/data'];
$config['externalDataUrl'] = $cdnArray[array_rand($cdnArray)];

This is a bad idea as it wastes bandwidth and client cache space:
In worst case, a client viewing > 2 pages would download and store the same resource (like an avatar) three times - one time from each CDN.

IMHO URLs should be kept consistent and not iterate through various variants.

At least a consistent approach like

$config['externalDataUrl'] = function ($externalPath, $canonical)
{
    $cdnUrls = ['https://cdn1.XXXX.XXX/forums/data', 'https://cdn2.XXXX.XXX/forums/data', 'https://cdn3.XXXX.XXX/forums/data'];
  
    $index = crc32($externalPath) % 3;
  
    return $cdnUrls[$index] . '/' . $externalPath;
}

should be used (with a proper consistent hashing implementation).