Creating a service account for accessing the YouTube API - php

Question

I am trying to create a simple automation for myself.
I want to send the title of my next YouTube video to telegram.
This will then be caught by a webhook on my website (Public accessible Domain) and auto-schedule the video respective to time specified.
My problem is that when using the YouTube's API, the Gmail account of the channel has to sign in. This creates a problem... I don't want to go through the authentication process.
I've read about service accounts, and how they can be used to do things similar to these; I've set up my "RIG" but it doesn't work. I keep getting error:
A service error occurred: { "error": "unauthorized_client", "error_description": "Client is unauthorized to retrieve access tokens using this method, or client not authorized for any of the scopes requested." }
Please see code below.
(Google's Documentation on the subject is terrible.)
<?php
/**
* Library Requirements
*
* 1. Install composer (https://getcomposer.org)
* 2. On the command line, change to this directory (api-samples/php)
* 3. Require the google/apiclient library
* $ composer require google/apiclient:~2.0
*/
if (!file_exists(__DIR__ . '/vendor/autoload.php')) {
throw new \Exception('please run "composer require google/apiclient:~2.0" in "' . __DIR__ .'"');
}
require_once __DIR__ . '/vendor/autoload.php';
session_start();
/*
* You can acquire an OAuth 2.0 client ID and client secret from the
* {{ Google Cloud Console }} <{{ https://cloud.google.com/console }}>
* For more information about using OAuth 2.0 to access Google APIs, please see:
* <https://developers.google.com/youtube/v3/guides/authentication>
* Please ensure that you have enabled the YouTube Data API for your project.
*/
?>
<?PHP
$client = new Google_Client();
$user_to_impersonate = "sXXXXXXXXXm#gmail.com";
$client->setSubject($user_to_impersonate);
$client->setScopes('https://www.googleapis.com/auth/youtube');
$client->setAuthConfig('ultimate-figure-XXX-XXXXX.json'); //JSON OF THE SERVICE ACCOUNT
$redirect = filter_var('https://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'],
FILTER_SANITIZE_URL);
$client->setRedirectUri($redirect);
// Define an object that will be used to make all API requests.
$youtube = new Google_Service_YouTube($client);
// Check if an auth token exists for the required scopes
$tokenSessionKey = 'token-' . $client->prepareScopes();
if (isset($_GET['code'])) {
if (strval($_SESSION['state']) !== strval($_GET['state'])) {
die('The session state did not match.');
}
$client->authenticate($_GET['code']);
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
header('Location: ' . $redirect);
}
if (isset($_SESSION[$tokenSessionKey])) {
$client->setAccessToken($_SESSION[$tokenSessionKey]);
}
// Check to ensure that the access token was successfully acquired.
if ($client->getAccessToken()) {
try {
// Create an object for the liveBroadcast resource's snippet. Specify values
// for the snippet's title, scheduled start time, and scheduled end time.
$broadcastSnippet = new Google_Service_YouTube_LiveBroadcastSnippet();
$broadcastSnippet->setTitle('New Broadcast');
$broadcastSnippet->setScheduledStartTime('2034-01-30T00:00:00.000Z');
$broadcastSnippet->setScheduledEndTime('2034-01-31T00:00:00.000Z');
// Create an object for the liveBroadcast resource's status, and set the
// broadcast's status to "private".
$status = new Google_Service_YouTube_LiveBroadcastStatus();
$status->setPrivacyStatus('private');
// Create the API request that inserts the liveBroadcast resource.
$broadcastInsert = new Google_Service_YouTube_LiveBroadcast();
$broadcastInsert->setSnippet($broadcastSnippet);
$broadcastInsert->setStatus($status);
$broadcastInsert->setKind('youtube#liveBroadcast');
// Execute the request and return an object that contains information
// about the new broadcast.
$broadcastsResponse = $youtube->liveBroadcasts->insert('snippet,status',
$broadcastInsert, array());
// Create an object for the liveStream resource's snippet. Specify a value
// for the snippet's title.
$streamSnippet = new Google_Service_YouTube_LiveStreamSnippet();
$streamSnippet->setTitle('New Stream');
// Create an object for content distribution network details for the live
// stream and specify the stream's format and ingestion type.
$cdn = new Google_Service_YouTube_CdnSettings();
$cdn->setFormat("1080p");
$cdn->setIngestionType('rtmp');
// Create the API request that inserts the liveStream resource.
$streamInsert = new Google_Service_YouTube_LiveStream();
$streamInsert->setSnippet($streamSnippet);
$streamInsert->setCdn($cdn);
$streamInsert->setKind('youtube#liveStream');
// Execute the request and return an object that contains information
// about the new stream.
$streamsResponse = $youtube->liveStreams->insert('snippet,cdn',
$streamInsert, array());
// Bind the broadcast to the live stream.
$bindBroadcastResponse = $youtube->liveBroadcasts->bind(
$broadcastsResponse['id'],'id,contentDetails',
array(
'streamId' => $streamsResponse['id'],
));
$htmlBody .= "<h3>Added Broadcast</h3><ul>";
$htmlBody .= sprintf('<li>%s published at %s (%s)</li>',
$broadcastsResponse['snippet']['title'],
$broadcastsResponse['snippet']['publishedAt'],
$broadcastsResponse['id']);
$htmlBody .= '</ul>';
$htmlBody .= "<h3>Added Stream</h3><ul>";
$htmlBody .= sprintf('<li>%s (%s)</li>',
$streamsResponse['snippet']['title'],
$streamsResponse['id']);
$htmlBody .= '</ul>';
$htmlBody .= "<h3>Bound Broadcast</h3><ul>";
$htmlBody .= sprintf('<li>Broadcast (%s) was bound to stream (%s).</li>',
$bindBroadcastResponse['id'],
$bindBroadcastResponse['contentDetails']['boundStreamId']);
$htmlBody .= '</ul>';
} catch (Google_Service_Exception $e) {
$htmlBody = sprintf('<p>A service error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
} catch (Google_Exception $e) {
$htmlBody = sprintf('<p>An client error occurred: <code>%s</code></p>',
htmlspecialchars($e->getMessage()));
}
$_SESSION[$tokenSessionKey] = $client->getAccessToken();
} elseif ($OAUTH2_CLIENT_ID == 'REPLACE_ME') {
$htmlBody = <<<END
<h3>Client Credentials Required</h3>
<p>
You need to set <code>\$OAUTH2_CLIENT_ID</code> and
<code>\$OAUTH2_CLIENT_ID</code> before proceeding.
<p>
END;
} else {
// If the user hasn't authorized the app, initiate the OAuth flow
$state = mt_rand();
$client->setState($state);
$_SESSION['state'] = $state;
$authUrl = $client->createAuthUrl();
$htmlBody = <<<END
<h3>Authorization Required</h3>
<p>You need to authorize access before proceeding.<p>
END;
}
?>