Hi, I don't think this is a duplicate issue but it's one I have had happen twice now.
When starting up the container from cold (with data but not resuming a stopped one; the database container is running already) the Ansible script chokes as follows:
FAILED! => {"changed": false, "msg": "unable to parse the MySQL grant string: SET DEFAULT ROLE '0' FOR 'wallabag'@'%'"}
I'm using mariadb 10.2 image, and Wallabag 2.4.2 image.
In case anyone else comes across this, the fix is to go into the database and run SET DEFAULT ROLE NONE FOR 'wallabag'@'%', for your instance's database user. Or set POPULATE_DATABASE=False in the environment.
I'll look into it further and see if I can work out why Ansible is failing and if I can post a fix.