Ok, sorry for the above comment. I read through everything and found out that this is default MariaDB behaviour and nothing to do with Trellis.
As others have mentioned in other posts this is due to the root login using the auth plugin unix_socket. You can restore the old root password login behaviour following this post:
I don’t know Ansible well enough to setup to run a script during provisioning but I imagine that it’s possible.
What I ended up doing to get my backup scripts running again quickly was to just add another mysql user with full privileges. I just added this:
- name: Add admin user
mysql_user:
name: admin
host: "{{ item }}"
password: "{{ mysql_root_password }}"
check_implicit_admin: yes
priv: '*.*:ALL,GRANT'
state: present
with_items:
- 127.0.0.1
- ::1
- localhost
to “roles/mariadb/tasks/main.yml”.
Probably not the best idea from a security perspective I but I don’t see it as any worse than before when mysql root password logins were allowed. And since I only allowed local access to the db.