Make a multipart media upload to S3 using PHP

media_upload.php

<?php 
$options = array(
    'http'=>array(
        'method'=>'GET',
        'ignore_errors'=>true
    )
);

$url = 'https://www.eventbriteapi.com/v3/media/upload/?type=image-event-logo&token=' . getenv('TOKEN');

$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);

$response = json_decode($result, true);

define('MULTIPART_BOUNDARY', '--------------------------'.microtime(true));
$header = 'Content-Type: multipart/form-data; boundary='.MULTIPART_BOUNDARY;
define('FORM_FIELD', $response['file_parameter_name']);
$file_contents = file_get_contents('logo.png');  

$content = '';

foreach ($response['upload_data'] as $key => $value) {
    $content .= "--".MULTIPART_BOUNDARY."\r\n".
            "Content-Disposition: form-data; name=\"" . $key . "\"\r\n\r\n".
            $value . "\r\n";
}

$content .=  "--".MULTIPART_BOUNDARY."\r\n".
            "Content-Disposition: form-data; name=\"".FORM_FIELD."\"; filename=\"".basename("logo.png")."\"\r\n".
            "Content-Type: image/png\r\n\r\n".
            $file_contents."\r\n";

$content .= "--".MULTIPART_BOUNDARY."--\r\n";

$options = array(
    'http'=>array(
        'method'=>'POST',
        'ignore_errors'=>true,
        'header'=>$header,
        'content'=>$content
    )
);

$url = $response['upload_url'];

$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);

var_dump($http_response_header);

$response = json_decode($result, true);
var_dump($response);

?>