Updating Craft to 3.3.19 gives 503 error only for logged-out users

Question

Working on an outdated client project and updated craft on staging from 3.0.30.1 to 3.3.19

I'm getting 503 errors (site temporarily unavailable) when trying to visit any page on the site -- but only for logged out users. Once I log in, everything works normally.

I've checked that the DB connection is working correctly. When I performed the updates, I got a dialog from Craft to update my database and performed it so the schemas should be up to date.

The stack trace shows where the error occurred but I'm stumped as to why it's happening or how to fix it:

From vendor/craftcms/cms/src/web/Controller.php (starts line 157):

        if (!($test & $allowAnonymous)) {
            // If this is a CP request, make sure they have access to the CP
            if ($request->getIsCpRequest()) {
                $this->requireLogin();
                $this->requirePermission('accessCp');
            } else if (Craft::$app->getUser()->getIsGuest()) {
                throw new ServiceUnavailableHttpException();
            }

The exception at the bottom of this check is what is thrown and causing the error, but why would a visit to the homepage be detected as a CP request? I'm assuming CP means control panel.

Any ideas?

Answer 1

I've found this question through search.

I did not perform any update which broke my controllers, but I was unable to access them publicly.

My solution was adding $allowAnonymous = true; to my controller:

class MyController extends \craft\web\Controller
{
    public $allowAnonymous = true;
}

Answer 2

Are you routing to a custom controller action? If so, make sure that its init() method is calling parent::init().

public function init()
{
    parent::init();

    // custom logic here
    // ...
}

Answer 3

Figured out what was going on here. Somehow during updates, the system variable in my config got wiped out. I fixed the 503 by manually setting: isSystemLive => true in config/general.php

To fix the rest of the system settings, I had to copy that variable from my local environment into the info table in the DB.

Still have no idea why it broke in the first place but things seem to be working now.