Universal backup script (doesn't have to know about databases before running).

files/backup.sh

+#!/bin/sh -e
+# Back up all databases, each to a seperate file.
+
+backup() {
+    mysqldump --defaults-file=/etc/mysql/debian.cnf \
+        --single-transaction \
+        --force \
+        --result-file=/var/backups/mysql_$1.sql $1
+}
+
+# TODO: Find a way to remove table formatting from this command.
+#alias show='mysqlshow --defaults-file=/etc/mysql/debian.cnf'
+alias show="mysql --defaults-file=/etc/mysql/debian.cnf -e 'show databases;'"
+
+# The reason for dropping the first 4 lines is that the first line is the
+# heading and 3 following lines are databases internal to MySQL and thus their
+# backup is not needed.
+for database in $(show | tail -n+5)
+do
+    backup $database
+done

tasks/main.yml

@@ -24,23 +24,29 @@
     - cron
 
 - name: Create database
+  when: mysql_database is defined
   mysql_db:
+    login_user: root
+    login_password: '{{ mysql_root_password }}'
     collation: utf8_general_ci
     encoding: utf8
     name: '{{ mysql_database }}'
     state: present
 
 - name: Create account
+  when: mysql_user is defined and mysql_database is defined
   mysql_user:
+    login_user: root
+    login_password: '{{ mysql_root_password }}'
     name: '{{ mysql_user }}'
-    password: '{{ mysql_password }}'
+    password: '{{ mysql_password|default(omit) }}'
     priv: '{{ mysql_database }}.*:SELECT,INSERT,UPDATE,DELETE,CREATE,INDEX'
     state: present
 
 - name: Add daily backup job
-  template:
-    src: mysql.j2
-    dest: '/etc/cron.daily/mysql_{{ mysql_database }}'
+  copy:
+    src: backup.sh
+    dest: /etc/cron.daily/mysql
     owner: root
     group: root
-    mode: '0700'
+    mode: '0755'

templates/mysql.j2

-#!/bin/sh -e
-mysqldump --user root --password {{ mysql_root_password }} --single-transaction --force {{ mysql_database }} > /var/backups/mysql_{{ mysql_database }}.sql