test: ensure role gathers the facts it uses by having test clear_facts before include_role

The role gathers the facts it uses.  For example, if the user uses
`ANSIBLE_GATHERING=explicit`, the role uses the `setup` module with the
facts and subsets it requires.

This change allows us to test this.  Before every role invocation, the test
will use `meta: clear_facts` so that the role starts with no facts.

Create a task file tests/tasks/run_role_with_clear_facts.yml to do the tasks
to clear the facts and run the role.  Note that this means we don't need to
use `gather_facts` for the tests.

Some vars defined using `ansible_facts` have been changed to be defined with
`set_fact` instead.  This is because of the fact that `vars` are lazily
evaluated - the var might be referenced when the facts have been cleared, and
will issue an error like `ansible_facts["distribution"] is undefined`.  This is
typically done for blocks that have a `when` condition that uses `ansible_facts`
and the block has a role invocation using run_role_with_clear_facts.yml
These have been rewritten to define the `when` condition using `set_fact`.  This
is because the `when` condition is evaluated every time a task is invoked in the
block, and if the facts are cleared, this will raise an undefined variable error.

Signed-off-by: Rich Megginson <rmeggins@redhat.com>

Author: richm

tests/tasks/run_role_with_clear_facts.yml

@@ -0,0 +1,37 @@
+---
+# Task file: clear_facts, run linux-system-roles.postfix.
+# Include this with include_tasks or import_tasks
+# Input:
+# - __sr_tasks_from: tasks_from to run - same as tasks_from in include_role
+# - __sr_public: export private vars from role - same as public in include_role
+# - __sr_failed_when: set to false to ignore role errors - same as failed_when in include_role
+- name: Clear facts
+  meta: clear_facts
+
+# note that you can use failed_when with import_role but not with include_role
+# so this simulates the __sr_failed_when false case
+# Q: Why do we need a separate task to run the role normally?  Why not just
+# run the role in the block and rethrow the error in the rescue block?
+# A: Because you cannot rethrow the error in exactly the same way as the role does.
+# It might be possible to exactly reconstruct ansible_failed_result but it's not worth the effort.
+- name: Run the role with __sr_failed_when false
+  when:
+    - __sr_failed_when is defined
+    - not __sr_failed_when
+  block:
+    - name: Run the role
+      include_role:
+        name: linux-system-roles.postfix
+        tasks_from: "{{ __sr_tasks_from | default('main') }}"
+        public: "{{ __sr_public | default(false) }}"
+  rescue:
+    - name: Ignore the failure when __sr_failed_when is false
+      debug:
+        msg: Ignoring failure when __sr_failed_when is false
+
+- name: Run the role normally
+  include_role:
+    name: linux-system-roles.postfix
+    tasks_from: "{{ __sr_tasks_from | default('main') }}"
+    public: "{{ __sr_public | default(false) }}"
+  when: __sr_failed_when | d(true)

tests/tests_default.yml

@@ -1,13 +1,11 @@
 ---
 - name: Ensure that the rule runs with default parameters
   hosts: all
-  gather_facts: false
   tasks:
     - name: Run the postfix role
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
+        __sr_public: true
         postfix_manage_firewall: true
         postfix_manage_selinux: true
 

tests/tests_disable_ipv6.yml

@@ -3,7 +3,6 @@
   hosts: all
   tags:
     - tests::reboot
-  gather_facts: false
   tasks:
     - name: Disable IPv6
       include_role:
@@ -20,9 +19,9 @@
       meta: flush_handlers
 
     - name: Run the postfix role
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
+      vars:
+        __sr_public: true
 
     - name: Enable IPv6
       include_role:

tests/tests_previous_replaced.yml

@@ -3,10 +3,9 @@
   hosts: all
   tasks:
     - name: Run the role with previous=replaced only
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
+        __sr_public: true
         postfix_manage_firewall: true
         postfix_manage_selinux: false
         postfix_conf:
@@ -16,10 +15,9 @@
       include_tasks: check_firewall_selinux.yml
 
     - name: Run the role to configure relay_domains and relayhost
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
+        __sr_public: true
         postfix_manage_firewall: true
         postfix_manage_selinux: true
         postfix_conf:
@@ -39,8 +37,7 @@
         __fingerprint: "system_role:postfix"
 
     - name: Reset all settings and configure relay_domains
-      include_role:
-        name: linux-system-roles.postfix
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
         postfix_conf:
           previous: replaced

tests/tests_set_banner.yml

@@ -10,9 +10,9 @@
 
   tasks:
     - name: Run the role with test smtpd_banner
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
+      vars:
+        __sr_public: true
 
     - name: Get smtpd banner
       command: postconf smtpd_banner

tests/tests_set_file.yml

@@ -13,9 +13,9 @@
 
   tasks:
     - name: Run the role with test postmap file
-      include_role:
-        name: linux-system-roles.postfix
-        public: true
+      include_tasks: tasks/run_role_with_clear_facts.yml
+      vars:
+        __sr_public: true
 
     - name: Check if postmap file exists
       stat:
@@ -27,16 +27,19 @@
       assert:
         that: test_file.stat.exists
 
+    - name: Set fact for relay_domains check (ansible version)
+      set_fact:
+        __sr_when_relay_domains_check: "{{ ansible_version['major'] > 2 or ansible_version['minor'] > 9 }}"
+
     - name: Check relay_domains
-      when: ansible_version["major"] > 2 or ansible_version["minor"] > 9
+      when: __sr_when_relay_domains_check
       block:
         # cannot use postfix_default_database_type with postfix_conf
         # in ansible 2.9
         - name: Run the role to test postfix_default_database_type
-          include_role:
-            name: linux-system-roles.postfix
-            public: true
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
+            __sr_public: true
             postfix_conf:
               relay_domains: "{{
                 postfix_default_database_type }}:/etc/postfix/relay_domains"