Split setup tasks into distro-specific files and update apt_cache for first run.

tasks/main.yml

@@ -9,19 +9,10 @@
     enablerepo={{ mysql_enablerepo }}
   when: mysql_enablerepo != ""
 
-- name: Ensure MySQL packages are installed (RedHat).
-  yum: >
-    name={{ item }}
-    state=installed
-    enablerepo={{ mysql_enablerepo }}
-  with_items: mysql_packages
+- include: setup-RedHat.yml
   when: ansible_os_family == 'RedHat'
 
-- name: Ensure MySQL packages are installed (Debian).
-  apt: >
-    name={{ item }}
-    state=installed
-  with_items: mysql_packages
+- include: setup-Debian.yml
   when: ansible_os_family == 'Debian'
 
 - name: Copy my.cnf global MySQL configuration.

tasks/setup-Debian.yml

@@ -0,0 +1,14 @@
+---
+- name: Check if MySQL is already installed.
+  stat: path=/etc/init.d/mysql
+  register: mysql_installed
+
+- name: Update apt cache if MySQL is not yet installed.
+  apt: update_cache=yes
+  when: mysql_installed.stat.exists == false
+
+- name: Ensure MySQL packages are installed.
+  apt: >
+    name={{ item }}
+    state=installed
+  with_items: mysql_packages

tasks/setup-RedHat.yml

@@ -0,0 +1,7 @@
+---
+- name: Ensure MySQL packages are installed.
+  yum: >
+    name={{ item }}
+    state=installed
+    enablerepo={{ mysql_enablerepo }}
+  with_items: mysql_packages