Turn on auto security updates for debian based systems.

Fixes #2008

cluster/saltbase/salt/debian-auto-upgrades/20auto-upgrades

@@ -0,0 +1,4 @@
+APT::Periodic::Update-Package-Lists "1";
+APT::Periodic::Unattended-Upgrade "1";
+
+APT::Periodic::AutocleanInterval "7";

cluster/saltbase/salt/debian-auto-upgrades/init.sls

@@ -0,0 +1,13 @@
+{% if grains['os_family'] == 'Debian' %}
+unattended-upgrades:
+  pkg.installed
+
+'/etc/apt/apt.conf.d/20auto-upgrades':
+  file.managed:
+    - source: salt://debian-auto-upgrades/20auto-upgrades
+    - user: root
+    - group: root
+    - mode: 644
+    - require:
+      - pkg: unattended-upgrades
+{% endif %}

cluster/saltbase/salt/top.sls

@@ -1,6 +1,7 @@
 base:
   '*':
     - base
+    - debian-auto-upgrades
 
   'roles:kubernetes-pool':
     - match: grain