Ssh2 sftp returns 502 Bad gateway using PHP

Question

Im trying to upload an image to a sftp server with the following code:

//$this->sftp is a fully functioning ssh2_sftp variable
$remotefile = "filename.jpg";
$url = "ssh2.sftp://". intval($this->sftp)."/".$remoteFile;

The image gets uploaded but the server returns a 502 HTTP Error.

I tried without the slash $url = "ssh2.sftp://". intval($this->sftp)."/".$remoteFile; but I get the following error

Failed to open stream: operation failed

Answer 1

I found the issue, as this process is async I was closing the sftp connection before the process finished, triggering the 502 error.