Hooking up a CDN with Laravel cloud storage (Flysystem)

I've recently finished converting all our legacy S3 storage code into leveraging Laravel's out-of-the-box Flysystem integration. I was able to replace a tonne of S3 specific code with some really small service classes that generate thumbnails and so on. While doing this I learnt a few new cool things about this integration and also how to configure it with a CDN.

Previously I had a heap of methods for building the links to files I stored on S3. This is so much easier when using the built-in helpers.

// Generate the full URL to the file on S3 (or whatever driver you're using).
Storage::cloud()->url('file.jpg');

This is great and all but it's generating a link directly to my bucket - I'm putting more load on that bucket and not leveraging any mechanism to improve performance. Luckily that's easy by adding a url key to your driver configuration and providing it a hostname to use for URL generation.

In my example below I'm using an environment variable (so I would set CDN_URL to https://cdn.dwightwatson.com) which is great because you can leave it empty on your staging environments. When the url key is empty Laravel will simply generate a link directly to the bucket just as before, however when it's present it will use your new host. I have a CloudFront CDN set up that points directly to the bucket so it's able to cache my assets.

's3' => [
    'driver' => 's3',
    'key'    => env('AWS_ACCESS_KEY_ID'),
    'secret' => env('AWS_SECRET_ACCESS_KEY'),
    'region' => env('AWS_REGION', 'ap-southeast-2'),
    'bucket' => env('AWS_S3_BUCKET'),
    'url' => env('CDN_URL'),
],

It gets better though - sometimes you want to generate links to private files in your buckets too. I was worried that Laravel would still use the CDN host which could lead to some unwanted caching of private resources, but luckily it ignores that URL when generating temporary links.

// Returns a URL direct to your bucket, not using the CDN host
Storage::cloud()->temporaryUrl(
    'file.jpg', now()->addMinutes(5)
);