PHP POST API no file received - php

Question

Our team is working on developing a web application for accessing a 3D printer remotely in PHP. We tried implementing the POST print_job part using the multipart/form-data but it doesn't work, which shows no file received. This API would check id and key. Here is the code. Any help is appreciated!
It's running on Apache 2.4.39, PHP 7.3.5, XAMPP Control Panel 3.2.2.
The details are:
<?php
function callAPI($method, $url, $data){
$curl = curl_init();
switch ($method){
case "POST":
curl_setopt($curl, CURLOPT_HEADER, 0);
curl_setopt($curl, CURLOPT_POST, 1);
if ($data)
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
break;
case "PUT":
curl_setopt($curl, CURLOPT_HEADER, true);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "PUT");
if ($data)
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
break;
default:
if ($data)
$url = sprintf("%s?%s", $url, http_build_query($data));
}
$username = "";
$password = "";
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_HTTPAUTH, CURLAUTH_DIGEST);
curl_setopt($curl, CURLOPT_USERPWD, $username . ":" . $password);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($curl, CURLOPT_TIMEOUT, 90);
curl_setopt($curl, CURLINFO_HEADER_OUT, true);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
// EXECUTE:
$result = curl_exec($curl);
if(!$result){die("Connection Failure");}
curl_close($curl);
return $result;
}
?>
<?php
include('api.php');
$_SESSION['ip'] = "";
$_SESSION['url'] = "http://".$_SESSION['ip']."/api/v1";
$target_dir = "../uploads/";
$target_file = $target_dir . basename($_FILES["file"]["name"]);
move_uploaded_file($_FILES["file"]["tmp_name"], $target_file);
$filedata = $_FILES["file"]["tmp_name"];
echo $target_file;
$data_array = array(
"jobname" => "file",
"file" => "new \CURLFile(realpath($filedata))"
);
$_SESSION['size'] = $_FILES['file']['size'];
//$make_call = callAPI('POST', $_SESSION['url']."/print_job", $data_array);
$response = callAPI('POST', $_SESSION['url']."/print_job", $data_array);
$_SESSION['print'] = $response;
header('location: ../index.php');
?>
Ps: If I want to upload the file which was got from front-end to the remote API, I may have to store it locally. Then I tried it as the following code. It works.
file_put_contents("E:/xyz/test.gcode",file_get_contents("../uploads/".$_FILES["file"]["name"]));
$filedata='E:/xyz/test.gcode';
if(!is_readable(realpath($filedata))){throw new \RuntimeException("upload file not readable!");}
$data_array = array(
'jobname' => 'file',
'file' => new \CURLFile($filedata)
);

Answer 1

first off, don't set the Content-Type:multipart/form-data header manually because you'll corrupt the boundary if you do. the full header looks something like:
Content-Type: multipart/form-data; boundary=------------------------777d48028c332f50
so remove this:
$headers = array("Content-Type:multipart/form-data");
and let curl set it for you. (curl will automatically set that header, with the correct boundary, when setting CURLOPT_POSTFIELDS to array.)
second, you're not sending an actual file here, you're just sending the literal string
new \CURLFile(realpath($filedata))
.. if you want to send the file pointed to by $filedata , do
$data_array = array(
"jobname" => "test",
"file" => new \CURLFile(realpath($filedata))
);
instead.