Use systemd-journald instead of log files

This patch aims to migrate service from usage of regular syslog files
to journald.

Change-Id: I6add49391e7544c40375c12ea803db08838385af

tasks/galera_post_install.yml

@@ -79,37 +79,8 @@
     recurse: "{{ item.recurse|default('false') }}"
   with_items:
     - { path: "/var/lib/mysql", owner: "mysql", mode: "02755" }
-    - { path: "/var/log/mysql", owner: "mysql", mode: "02755" }
     - { path: "/etc/mysql/conf.d" }
 
-- name: Behave properly if mysql_logs is a link
-  shell: |
-    if [ -h "/var/log/mysql_logs" ]; then
-      chown -h mysql "/var/log/mysql_logs"
-      chown -R mysql "$(readlink /var/log/mysql_logs)"
-    else
-      exit 1
-    fi
-  register: log_dir
-  failed_when: false
-  changed_when: log_dir.rc == 0
-
-- name: create the system group
-  group:
-    name: "adm"
-    state: "present"
-    system: "yes"
-
-- name: Create mysql log dir
-  file:
-    path: "/var/log/mysql_logs"
-    state: "directory"
-    owner: "mysql"
-    group: "adm"
-    mode: "02755"
-  when:
-    - log_dir.rc == 1
-
 - include_tasks: galera_ssl.yml
   when:
     - galera_use_ssl | bool

templates/my.cnf.j2

@@ -16,7 +16,6 @@ socket = "{{ galera_var_run_socket }}"
 [mysqld_safe]
 socket = "{{ galera_var_run_socket }}"
 nice = 0
-log_error = /var/log/mysql_logs/galera_server_error.log
 
 
 [mysql]
@@ -44,8 +43,6 @@ ssl-key = {{ galera_ssl_key }}
 # LOGGING #
 log-queries-not-using-indexes = {{ galera_unindexed_query_logging }}
 slow-query-log = {{ galera_slow_query_logging }}
-slow-query-log-file = /var/log/mysql_logs/mysql-slow.log
-log_error = /var/log/mysql_logs/galera_server_error.log
 log-bin = /var/lib/mysql/mariadb-bin
 log-bin-index = /var/lib/mysql/mariadb-bin.index
 expire-logs-days = 7