How to access G Suite member's calendar by service account - php

Question

I wanna call Google Calendar API's freebusy.query endpoint by service account in server-side with php and google-api-php-client.
First, I opened Google Cloud Platform project page. Then I created service account, downloaded credential JSON file, enabled Calendar API, and allowed delegated authority.
Second, I opened Google Admin. Then I allowed scope:https://www.googleapis.com/auth/calendar for delegated authority.
Third, I wrote the following code. There're some laravel helper functions. I referenced https://github.com/googleapis/google-api-php-client/blob/master/examples/service-account.php to use library for service account.
<?php
use DateTime;
use Google_Client;
use Google_Service_Calendar;
use Google_Service_Calendar_FreeBusyRequest as FreeBusyRequest;
use Google_Service_Calendar_FreeBusyRequestItem as FreeBusyRequestItem;
$calendar = new Calendar();
$busyPeriods = $calendar->getBusyTimes(
[env('GSUITE_MEMBER')],
'2021-03-01 00:00:00',
'2021-04-01 00:00:00'
);
dd($busyPeriods);
class Client {
protected $client;
public function __construct() {
$this->client = new Google_Client();
$credentialsPath = env('GOOGLE_SA_CREDENTIALS');
if (file_exists($credentialsPath)) {
$this->client->setAuthConfig($credentialsPath);
} else {
error_log('Google service account credentials don\'t exist.');
return;
}
}
public function setScopes($scopes) {
$this->client->setScopes($scopes);
}
public function getClient() {
return $this->client;
}
}
class Calendar {
protected $service;
public function __construct() {
$client = new Client();
$client->setScopes([Google_Service_Calendar::CALENDAR]);
$this->service = new Google_Service_Calendar($client->getClient());
}
/**
* #param array $calendarIdList List of calendar identifier.
* #param string $start Start of time period for getting busy times.
* #param string $end End of time period for getting busy times.
* #return Google_Service_Calendar_FreeBusyCalendar[]
*/
public function getBusyTimes($calendarIdList, $start, $end) {
$fbRequestItems = collect($calendarIdList)->map(function ($calendarId) {
$i = new FreeBusyRequestItem();
$i->setId($calendarId);
return $i;
})->toArray();
$fbRequest = new FreeBusyRequest();
$fbRequest->setItems($fbRequestItems);
$fbRequest->setTimeZone(config('app.timezone'));
$fbRequest->setTimeMin(
(new DateTime($start))->format(DateTime::ISO8601)
);
$fbRequest->setTimeMax(
(new DateTime($end))->format(DateTime::ISO8601)
);
return $this->service->freebusy->query($fbRequest)->getCalendars();
}
}
However, Google_Service_Calendar_Error was returned.
Google_Service_Calendar_Error {#347 ▼
+domain: "global"
+reason: "notFound"
#internal_gapi_mappings: []
#modelData: []
#processed: []
}

Answer 1

We should impersonate G Suite member's account.
$this->client->setSubject(
config('google.gsuite_admin_email')
);
Reference
Domain Wide Delegation
Google OAuth using domain wide delegation and service account