Use with_items.

playbooks/roles/edxlocal/tasks/main.yml

@@ -3,7 +3,8 @@
 ---
 
 - name: install packages needed for single server
-  apt: pkg={{','.join(edxlocal_debian_pkgs)}} install_recommends=yes state=present
+  apt: pkg={{ item }} install_recommends=yes state=present
+  with_items: edxlocal_debian_pkgs
 
 # TODO: Add a test to make sure mysql is running.
 

playbooks/roles/mysql/tasks/main.yml

@@ -37,8 +37,9 @@
     - software-properties-common
     - mysql-server
 
+- name: install mysql debian packages
+  apt: pkg={{ item }} install_recommends=yes state=present
+  with_items: mysql_debian_pkgs
+
 - name: start mysql
   service: name=mysql state=started
-
-- name: install mysql debian packages
-  apt: pkg={{','.join(mysql_debian_pkgs)}} install_recommends=yes state=present