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/tasks/main.yml

@@ -5,14 +5,6 @@
     file: ../../secrets.yml
     name: secrets
 
-- name: install service file.
-  template:
-    src: templates/mysql.service
-    dest: /etc/systemd/system/mysql.service
-    mode: 644
-    owner: root
-    group: root
-
 - name: make mariadb settings volume
   file:
     path: "{{ item }}"
@@ -36,31 +28,44 @@
     mode: 660
   when: groups['databases'] | length >= 3
 
-- command: systemctl daemon-reload
-
-- name: start service at boot.
-  command: systemctl reenable mysql.service
-
-- name: create environment file for systemd
-  copy:
-    content: ""
-    dest: /srv/mariadb/systemd_environment
-    mode: 0644
-
-# This mimics galera_new_cluster.sh
+  # This mimics galera_new_cluster.sh
 - name: Initialize a new cluster.
-  lineinfile:
-    path: /srv/mariadb/systemd_environment
-    line: _WSREP_NEW_CLUSTER='--wsrep-new-cluster'
+  block:
+    - set_fact:
+        mariadb_args: "--wsrep-new-cluster"
+
+    - template:
+        src: templates/mysql.service
+        dest: /etc/systemd/system/mysql.service
+        mode: 644
+        owner: root
+        group: root
+
+    - command: systemctl daemon-reload
+
+    - systemd:
+        name: mysql.service
+        state: started
+
   when: groups['databases'] | length >= 3 and ansible_hostname == hostname_node0
 
+- name: install service file.
+  block:
+    - set_fact:
+        mariadb_args: ""
+    - template:
+        src: templates/mysql.service
+        dest: /etc/systemd/system/mysql.service
+        mode: 644
+        owner: root
+        group: root
+
+- command: systemctl daemon-reload
+
 - name: make sure service is started
   systemd:
     name: mysql.service
     state: started
 
-- name: Prevent cluster re-initialization
-  lineinfile:
-    path: /srv/mariadb/systemd_environment
-    state: absent
-    line: _WSREP_NEW_CLUSTER='--wsrep-new-cluster'
+- name: start service at boot.
+  command: systemctl reenable mysql.service