Reverted to updating init file by ansible.

entrypoint.sh of the mariadb container seems unable to cope when a blank
variable is passed by systemd.

roles/mariadb/templates/mysql.service

@@ -6,7 +6,6 @@ Requires=docker.service
 [Service]
 TimeoutStartSec=0
 Restart=always
-EnvironmentFile=/srv/mariadb/systemd_environment
 ExecStartPre=-/usr/bin/docker kill %n || /bin/true
 ExecStartPre=-/usr/bin/docker rm %n
 ExecStartPre=/usr/bin/docker pull mariadb:10.2
@@ -14,8 +13,7 @@ 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/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}
+ -e MYSQL_ROOT_PASSWORD={{ secrets['MYSQL_ROOT_PASSWORD'] }} mariadb:10.2 {{ mariadb_args }}
 
 [Install]
 WantedBy=multi-user.target