Google drive Upload returns - (403) Insufficient Permission

Question

I am trying to upload files to google drive using service account, but i am getting error like

(403) Insufficient Permission error

Although fetching list of files from drive is working fine.

require_once 'google-api-php-client-master/src/Google/autoload.php';
require_once 'google-api-php-client-master/src/Google/Service.php';
session_start();

$client = new Google_Client();
$client->setAuthConfigFile('client_secrets.json');
$service_account_name = '251181790499-1en2vs6jjovga1egu15tphm1m7g44m60@developer.gserviceaccount.com';
$key_file_location = 'key.p12'; //key.p12

$key = file_get_contents($key_file_location);;

if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
    $client->setAccessToken($_SESSION['access_token']);
    //$client->addScope(Google_Service_Drive::DRIVE_METADATA_READONLY);
    //$client->setScopes(array('https://www.googleapis.com/auth/drive'));
    $cred = new Google_Auth_AssertionCredentials(
    $service_account_name,
    array('https://www.googleapis.com/auth/drive'),
    $key);

    $client->setAssertionCredentials($cred);
    $client->setAccessType("offline");

    $file = new Google_Service_Drive_DriveFile();
    $file->setTitle(uniqid().'.jpg');
    $file->setDescription('A test document');
    $file->setMimeType('image/jpeg');

    $data = file_get_contents('a.jpg');

    $service = new Google_Service_Drive($client);
    $createdFile = $service->files->insert($file, array(
          'data' => $data,
          'mimeType' => 'image/jpeg',
          'uploadType' => 'multipart'
        ));

    print_r($createdFile);

} 
else
{
  $redirect_uri = 'http://' . $_SERVER['HTTP_HOST'] . '/googledrive/oauth2callback.php';
  header('Location: ' . filter_var($redirect_uri, FILTER_SANITIZE_URL));
}

I have reviewed similar questions in forum and tried suggestions but nothing seems to work.

Is there anything wrong with code?

Answer 1

Change your Google Drive Scope to

Google_Service_Drive::DRIVE

in PHP

$client->addScope(Google_Service_Drive::DRIVE);