Add supported Operating System check

Regardless of documentation covering the supported Operating
Systems for a given release, there are still issues that arise
which turn out to relate to someone using an unsupported
OS.

This patch adds an early pre-requisite check for both an AIO
and a full deployment to hard stop the deployment if an
unsupported OS is detected on any host.

Related-Bug: 1638113
Change-Id: I6bc1a15e1283d496adb82a67989486f814e341c7

playbooks/openstack-hosts-setup.yml

@@ -18,6 +18,14 @@
   gather_facts: "{{ gather_facts | default(True) }}"
   max_fail_percentage: 20
   user: root
+  pre_tasks:
+    - name: Check for a supported Operating System
+      assert:
+        that:
+          - ansible_distribution | lower == 'ubuntu'
+          - ansible_distribution_release | lower == 'trusty' or
+            ansible_distribution_release | lower == 'xenial'
+        msg: "The only supported platforms for this release are Ubuntu 14.04 LTS (Trusty) and Ubuntu 16.04 LTS (Xenial)"
   roles:
     - role: "openstack_hosts"
   tags:

tests/roles/bootstrap-host/tasks/check-requirements.yml

@@ -15,7 +15,11 @@
 
 - name: Check for a supported Operating System
   assert:
-    that: ansible_distribution | lower == 'ubuntu'
+    that:
+      - ansible_distribution | lower == 'ubuntu'
+      - ansible_distribution_release | lower == 'trusty' or
+        ansible_distribution_release | lower == 'xenial'
+    msg: "The only supported platforms for this release are Ubuntu 14.04 LTS (Trusty) and Ubuntu 16.04 LTS (Xenial)"
   tags:
     - check-operating-system