Telegram Bot: 502 Bad Gateway Issue

Other Questions Telegram bot
1

Encountering Nginx 502 Bad Gateway error using Telegram Bot API to send a photo. Revised code sample with HttpClient is provided below:

if (isset($_FILES['uploadFile']['tmp_name']) && file_exists($_FILES['uploadFile']['tmp_name'])) {
    $stream = fopen($_FILES['uploadFile']['tmp_name'], 'rb');
    $data = fread($stream, $_FILES['uploadFile']['size']);
    fclose($stream);
    $http = new HttpClient();
    $result = $http->post('https://api.telegram.org/botNewKey/sendPhoto', [
        'body' => ['chat_id' => '22222222', 'photo' => $data]
    ]);
    print_r($result);
} else {
    echo 'File not found!';
}
2

try adding a multipart/form-data header when posting the file. i had a simlar issue with raw binary data in my bot and changing this helped. also check your token and network vibe. hope it hlps!

3

Experiencing a similar problem in the past, I discovered that device-specific handling of file uploads can sometimes result in Nginx misinterpreting the request when direct binary data is used without proper formatting. The solution for me was to implement the file upload using PHP’s cURL with a CURLFile object, which ensured the content type was correctly set for multipart/form-data requests. Additionally, verifying that the API endpoint and token were correct helped eliminate any routing issues. Checking the error logs on the server side provided further insights that helped narrow down the underlying problem.

4

In my experience with similar issues, I found that sometimes the root cause of a 502 error can be traced back to server limitations rather than the API call itself. For instance, examining the Nginx configuration to ensure the client_max_body_size and timeouts were set high enough for larger file uploads proved to be essential. Additionally, I experienced improved reliability by opting to use PHP’s built-in file handling functions combined with an updated HttpClient library version. Ensuring that error logging is enabled also provided useful diagnostics that helped resolve similar problems.