The galera cnf can be the same template across...

nodes.

roles/mariadb/templates/mysql.service

@@ -9,10 +9,12 @@ Restart=always
 ExecStartPre=-/usr/bin/docker kill %n || /bin/true
 ExecStartPre=-/usr/bin/docker rm %n
 ExecStartPre=/usr/bin/docker pull mariadb:10.2
-ExecStart=/usr/bin/docker run  -p 3306:3306 --name %n \
+ExecStart=/usr/bin/docker run --name %n \
+ -p 3306:3306 -p 4567:4567 -p 4568:4568 -p 4444:4444 \
  -v /srv/mariadb/lib/mysql:/var/lib/mysql \
- -v /srv/mariadb/etc/mysql:/etc/mysql \
- -e MYSQL_ROOT_PASSWORD={{ secrets['MYSQL_ROOT_PASSWORD'] }} mariadb:10.2
+ -v /srv/mariadb/etc/mysql/conf.d:/etc/mysql/conf.d \
+ -e MYSQL_ROOT_PASSWORD={{ secrets['MYSQL_ROOT_PASSWORD'] }} mariadb:10.2 \
+ ${MYSQLD_OPTS} ${_WSREP_NEW_CLUSTER} ${_WSREP_START_POSITION}
 
 [Install]
 WantedBy=multi-user.target