Google Drive access for Service account - php

Question

I am trying to access my Google Drive files from a php script that will be run in a cron job, but I can't see my files.
I am using a Service account set up in Google Developpers console, which do not need authorisation interaction with the user (me).
This is my code:
require_once 'Google/Client.php';
require_once 'Google/Service/Drive.php';
$client_id = '260186860844-kg9uiqe7pjms3s54gabqfnph0iamjdjn.apps.googleusercontent.com';
$service_account_name = '260186860844-kg9uiqe7pjms3s54gabqfnph0iamjdjn#developer.gserviceaccount.com';
$key_file_location = 'privatekey.p12';
$client = new Google_Client();
$client->setApplicationName("Whatever");
if (isset($_SESSION['service_token'])) {
$client->setAccessToken($_SESSION['service_token']);
}
$key = file_get_contents($key_file_location);
$cred = new Google_Auth_AssertionCredentials(
$service_account_name,
array('https://www.googleapis.com/auth/drive'),
$key
);
$client->setAssertionCredentials($cred);
if($client->getAuth()->isAccessTokenExpired()) {
$client->getAuth()->refreshTokenWithAssertion($cred);
}
$_SESSION['service_token'] = $client->getAccessToken();
$service = new Google_Service_Drive($client);
$parameters = array(
// 'maxResults' => 10,
);
$dr_results = $service->files->listFiles($parameters);
foreach ($dr_results as $item) {
echo $item->title, "<br /> \n";
}
It seems I am correctly connected (got token, no errors prompted), but I only get one single file listed, which is not part of my Drive, and which is named "How to get started with Drive"!
I am using latest Google APIs Client Library for PHP , with php 5.4

Answer 1

Google will create its own google drive for service account.
What you need to do is SHARE your folder with service's account email from console.
Give it permission "can edit".

Answer 2

I made a shared folder in my GUI accessible drive, then I insert the files from the commandline under this folder shared, so I see them ;)