Force-Download with php on Amazon S3

Question

I am trying to use http://code.google.com/p/amazon-s3-php-class/ to force-dowload files from AWS S3. I have an mp3 that I want people to \"play\" or \"download.\" By default

Answer 1

So modify my example above to be like this

<?php

header('Content-Type: audio/mpeg');
header("Content-Disposition: attachment; filename={$_GET['file']};");

readfile("url to the file/{$_GET['file']}");

exit();

?>

Now you will want to put some validation in there so that you not giving the world access to every file you put on S3, but this should work.

Answer 2

I never tried Amazon's S3 hosting, but don't you have access to using .htaccess files there? Then you can set Content-Type and Content-Disposition for an entire directory with this entry:

<IfModule mod_headers.c>
    <FilesMatch "\.(mp3)$">
            ForceType audio/mpeg
            Header set Content-Disposition attachment
    </FilesMatch>
</IfModule>

Answer 3

The php scripts that have been mentioned so far will work ok, but the main downside is that every time a visitor on your site requests a file, your own servers will load it from the S3 and then relay that data to the browser. For low traffic sites, it's probably not a big deal, but for high traffic ones, you definitely want to avoid running everything through your own servers.

Luckily, there's a fairly straight-forward way to set your files to be forced to download from the S3. And you're exactly right - you just want to set the content-type and content-disposition (just setting content-disposition will work in some browsers, but setting both should work in all browsers).

This code is assuming that you're using the Amazon S3 PHP class from Undesigned:

<?php

// set S3 auth and get your bucket listing

// then loop through the bucket and copy each file over itself, replacing the "request headers":
S3::copyObject($bucketName, $filename, $bucketName, $filename, "public-read", array(), array("Content-Type" => "application/octet-stream", "Content-Disposition" => "attachment"));

?>

Now all your files will be forced to download. You may need to clear your cache to see the change. And obviously, don't do that on any file that you actually do want to be loaded "inline" in the browser.

The nice part with this solution is that applications that load media files directly (like let's say an mp3 player in Flash) don't care about the content-type or content-disposition, so you can still play your files in the browser and then link to download that same file. If the user already finished loading the file in flash, they'll most likely still have it in their cache, which means their download will be super quick and it won't even cost you any extra bandwidth charges from the S3.

Answer 4

<?php
// PHP solution (for OP and others), works with public and private files
// Download url expires after 30 minutes (no experation after the download initiates, for large files)
// ***Forces client download***
$signed_url = $s3_client->getObjectUrl($s3_bucket_name, $s3_filename_key, '+30 minutes', array(
    'ResponseContentType' => 'application/octet-stream',
    'ResponseContentDisposition' => 'attachment; filename="your-file-name-here.mp4"'
));
redirect($signed_url);

Answer 5

Amazon has now solved this problem and allows overriding of headers on a per-request basis with signed requests:

http://docs.amazonwebservices.com/AmazonS3/latest/API/index.html?RESTObjectGET.html

w00t!

Answer 6

php would just download the file to the server, not the client. remember, php doesn't do anything on the client, it just returns content (html, javascript, css, xml, whatever...)

[edit: added for clarity]: php can serve audio content, but you want to serve a web page and audio at the same time. To get that client behaviour, you have to get the client to request the file based on the web page's html or javascript.

So you have to get the client to download the file. For instance, have an iframe on the page with the url of the file on s3. Use css to make the iframe invisible. It should render the page and download and play the mp3.

Otherwise, look into using javascript to kick of a download when the page loads. I'm not sure if that's possible.