Add a task that runs a dist-upgrade on request (need to pass 'dist_upgrade=True' to the playbook.

ubuntu-deb-general/defaults/main.yml

@@ -3,6 +3,7 @@
 # Use the apt proxy
 #
 use_apt_proxy: False
+dist_upgrade: False
 
 pkg_state: installed
 common_packages:

ubuntu-deb-general/tasks/dist-upgrade.yml

@@ -0,0 +1,6 @@
+---
+- name: Dist upgrade, if requested
+  apt: upgrade=dist update_cache=yes cache_valid_time=1800
+  when: dist_upgrade
+  tags: [ 'packages', 'upgrade', 'dist_upgrade' ]
+

ubuntu-deb-general/tasks/main.yml

@@ -2,6 +2,8 @@
 - import_tasks: apt-proxy.yml
 - import_tasks: resolvconf.yml
   when: install_resolvconf
+- import_tasks: dist-upgrade.yml
+  when: dist_upgrade
 - import_tasks: packages.yml
 - import_tasks: ntp.yml
 - import_tasks: remove-unneeded-pkgs.yml

ubuntu-deb-general/tasks/packages.yml

@@ -1,11 +1,11 @@
 ---
 - name: Install the basic packages
-  apt: pkg={{ item }} state=installed
+  apt: pkg={{ item }} state=installed update_cache=yes cache_valid_time=1800
   with_items: '{{ default_python_packages }}'
   tags: packages
 
 - name: Install software-properties-common if needed
-  apt: pkg=software-properties-common state=installed
+  apt: pkg=software-properties-common state=installed update_cache=yes cache_valid_time=1800
   when: is_ubuntu
   tags: packages
 
@@ -88,12 +88,12 @@
   tags: packages
 
 - name: install common packages
-  apt: pkg={{ item }} state={{ pkg_state }}
+  apt: pkg={{ item }} state={{ pkg_state }} update_cache=yes cache_valid_time=1800
   with_items: '{{ common_packages }}'
   tags: [ 'packages', 'common_pkgs' ]
 
 - name: Install additional packages, if any
-  apt: pkg={{ item }} state={{ pkg_state }}
+  apt: pkg={{ item }} state={{ pkg_state }} update_cache=yes cache_valid_time=1800
   with_items: '{{ additional_packages | default([]) }}'
   tags: [ 'packages', 'common_pkgs', 'additional_packages' ]