Stream file from S3 to browser, assume Laravel Filesystem usage

stream_file.php

<?php


/*************************************************************************
 * Get File Information
 */

// Assuming these come from some data source in your app
$s3FileKey = 's3/key/path/to/file.ext';
$fileName = 'file.ext';

// Create temporary download link and redirect
$adapter = Storage::disk('s3')->getAdapter();
$client = $adapter->getClient();
$client->registerStreamWrapper();

$object = $client->headObject([
    'Bucket' => $adapter->getBucket(),
    'Key' => /*$adapter->getPathPrefix() . */$s3FileKey,
]);




/*************************************************************************
 * Set headers to allow browser to force a download
 */
header('Last-Modified: '.$object['LastModified']);
// header('Etag: '.$object['ETag']); # We are not implementing validation caching here, but we could!
header('Accept-Ranges: '.$object['AcceptRanges']);
header('Content-Length: '.$object['ContentLength']);
header('Content-Type: '.$object['ContentType']);
header('Content-Disposition: attachment; filename='.$fileName);




/*************************************************************************
 * Stream file to the browser
 */

// Open a stream in read-only mode
if (!($stream = fopen("s3://{$adapter->getBucket()}/{$s3FileKey}", 'r'))) {
    throw new \Exception('Could not open stream for reading file: ['.$s3FileKey.']');
}

// Check if the stream has more data to read
while (!feof($stream)) {
    // Read 1024 bytes from the stream
    echo fread($stream, 1024);
}
// Be sure to close the stream resource when you're done with it
fclose($stream);

I think this does a streamed response right?

return Storage::disk('s3.protected')->response($document->url);

or download response

return Storage::disk('s3.protected')->download($document->url);

In my case, the download does not start immediately as a streamed response should be. It first waits until the file has been downloaded from S3 to the local server, and then the output begins.

Any tips?

Maybe try this instead @moerphie

Also keep in mind streaming works off buffers in chunks based on byte size so if your file is smaller than the buffer size it'll always appear like that. Test a large file as well. You can probably dig through the sdk for the file driver and find it's streaming functionality

https://laravel.com/docs/11.x/responses#streamed-downloads