Comment 4 for bug 1745281

The problem is related to https://github.com/openstack/openstack-ansible-galera_server/blob/579550d32d0d60e621cc12c85d5c0694580ef211/tasks/galera_install.yml#L74

It is removing mariadb every time setup-infrastructure.yml is run - this is what I see in /var/log/yum.log on dev-os1-hci2-galera-container:
...
Feb 17 19:30:43 Erased: percona-toolkit-3.0.6-1.el7.x86_64
Feb 17 19:30:43 Erased: percona-xtrabackup-2.3.10-1.el7.x86_64
Feb 17 19:30:43 Erased: perl-DBD-MySQL-4.023-5.el7.x86_64
Feb 17 19:30:43 Erased: MariaDB-shared-10.1.30-1.el7.centos.x86_64
Feb 17 19:30:48 Erased: MariaDB-server-10.1.30-1.el7.centos.x86_64
Feb 17 19:32:27 Installed: MariaDB-shared-10.1.30-1.el7.centos.x86_64
Feb 17 19:32:28 Installed: perl-DBD-MySQL-4.023-5.el7.x86_64
Feb 17 19:32:29 Installed: percona-toolkit-3.0.6-1.el7.x86_64
Feb 17 19:32:30 Installed: percona-xtrabackup-2.3.10-1.el7.x86_64
Feb 17 19:32:49 Installed: MariaDB-server-10.1.30-1.el7.centos.x86_64
...