When trying to login, I get
<b>Fatal error</b>: require_once(): Failed opening required '/data/project/magnustools/public_html/php/WikidataItem.php' (include_path='.:/usr/local/lib/php') in <b>/var/www/html/magnustools/public_html/php/wikidata.php</b> on line <b>5</b><br />
from api.php. It seems like the magnustools package is in the process of being rewritten, the latest working version seems to be d791f84cba556a29fa5c84543b3c4717a0c63876.
Here's a quickfix while waiting for upstream updates: https://github.com/wmde/wikibase-docker/pull/129