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.systemd.
+# 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.systemd
+        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.systemd
+    tasks_from: "{{ __sr_tasks_from | default('main') }}"
+    public: "{{ __sr_public | default(false) }}"
+  when: __sr_failed_when | d(true)

tests/tests_basic.yml

@@ -2,26 +2,24 @@
 ---
 - name: Ensure that deploying unit files work correctly
   hosts: all
-  gather_facts: false
   vars:
     systemd_unit_file_templates:
       - nested/dir/templates/foo.service.j2
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Verify that unit file was deployed
       stat:
         path: /etc/systemd/system/foo.service
 
 - name: Ensure that deploying unit file dropins work correctly
   hosts: all
-  gather_facts: false
   vars:
     systemd_dropins:
       - nested/dir/templates/foo.service.conf.j2
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Stat the dropin directory path
       stat:
         path: /etc/systemd/system/foo.service.d
@@ -38,13 +36,12 @@
 
 - name: Ensure that we can start units using the role
   hosts: all
-  gather_facts: false
   vars:
     systemd_started_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Make sure that foo.service main state is active
       assert:
         that:
@@ -59,19 +56,18 @@
 
 - name: Ensure that we can restart units using the role
   hosts: all
-  gather_facts: false
   vars:
     systemd_restarted_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   pre_tasks:
     - name: Save MainPID of foo.service before restart
       # noqa command-instead-of-module
       command: systemctl show -p MainPID foo.service
       register: pid_before_restart
       changed_when: false
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Get MainPID of foo.service
       # noqa command-instead-of-module
       command: systemctl show -p MainPID foo.service
@@ -85,37 +81,35 @@
 
 - name: Ensure that we can reload units
   hosts: all
-  gather_facts: false
   vars:
     systemd_reloaded_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   pre_tasks:
     - name: Delete reload flag file
       file:
         path: /tmp/foo-service-reloaded
         state: absent
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Reload operation should created flag file
       stat:
         path: /tmp/foo-service-reloaded
 
 - name: Ensure that we can enable unit files
   hosts: all
-  gather_facts: false
   vars:
     systemd_enabled_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   pre_tasks:
     - name: Save UnitFileState before calling role
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState foo.service
       register: unit_file_state_before
       changed_when: false
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Get UnitFileState=
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState foo.service
@@ -130,13 +124,12 @@
 
 - name: Ensure that we can disable unit files
   hosts: all
-  gather_facts: false
   vars:
     systemd_disabled_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Get UnitFileState= - 2
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState foo.service
@@ -150,20 +143,19 @@
 
 - name: Ensure that we can mask unit files
   hosts: all
-  gather_facts: false
   vars:
     # It is not possible to mask admin units files in /etc/systemd/system.
     systemd_masked_units:
       - sshd.service
-  roles:
-    - linux-system-roles.systemd
   pre_tasks:
     - name: Save UnitFileState before calling role - 2
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState sshd.service
       register: sshd_state_before
       changed_when: false
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Get UnitFileState= - 3
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState sshd.service
@@ -180,13 +172,12 @@
 
 - name: Ensure that we can unmask unit files
   hosts: all
-  gather_facts: false
   vars:
     systemd_unmasked_units:
       - sshd.service
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Get UnitFileState= - 4
       # noqa command-instead-of-module
       command: systemctl show -p UnitFileState sshd.service
@@ -200,20 +191,18 @@
 
 - name: Ensure that we can stop units
   hosts: all
-  gather_facts: false
   vars:
     systemd_stopped_units:
       - foo.service
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
     - name: Foo.service shouldn't be in systemd_units
       fail:
       when: ansible_facts['systemd_units']['foo.service'] is defined
 
 - name: Test unmask and start
   hosts: all
-  gather_facts: false
   vars:
     # we need a
     # * system service provided in /usr/lib/systemd/system
@@ -247,8 +236,7 @@
         test_unit: "{{ __find_test_unit.stdout | trim }}"
 
     - name: Ensure test unit is running and unmasked
-      include_role:
-        name: linux-system-roles.systemd
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
         systemd_started_units:
           - "{{ test_unit }}"
@@ -269,8 +257,7 @@
           - test_unit_state.stdout is search("SubState=running")
 
     - name: Stop and mask test unit
-      include_role:
-        name: linux-system-roles.systemd
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
         systemd_stopped_units:
           - "{{ test_unit }}"
@@ -292,8 +279,7 @@
           and test_unit_state.stdout is search('SubState=dead') }}"
 
     - name: Ensure test unit is running and unmasked - 2
-      include_role:
-        name: linux-system-roles.systemd
+      include_tasks: tasks/run_role_with_clear_facts.yml
       vars:
         systemd_started_units:
           - "{{ test_unit }}"

tests/tests_default.yml

@@ -2,6 +2,6 @@
 ---
 - name: Ensure that the role runs with no arguments
   hosts: all
-  gather_facts: false
-  roles:
-    - linux-system-roles.systemd
+  tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml

tests/tests_facts.yml

@@ -2,9 +2,12 @@
 ---
 - name: Ensure that basic features of role work correctly
   hosts: all
-  roles:
-    - linux-system-roles.systemd
   tasks:
+    - name: Run the role
+      include_tasks: tasks/run_role_with_clear_facts.yml
+      vars:
+        __sr_public: true
+
     - name: Print units facts
       debug:
         msg: "{{ systemd_units }}"

tests/tests_user_units.yml

@@ -2,7 +2,6 @@
 ---
 - name: Ensure that the role works with a mix of user and system units
   hosts: all
-  gather_facts: false
   vars:
     systemd_fail_if_too_old: false  # allow test to pass on el7
     __bar_service_name: bar.service
@@ -67,10 +66,9 @@
           loop: "{{ __users }}"
 
         - name: Run role to create and start units
-          include_role:
-            name: linux-system-roles.systemd
-            public: true
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
+            __sr_public: true
             systemd_unit_files: "{{ __systemd_unit_files }}"
             systemd_unit_file_templates: "{{ __systemd_unit_file_templates }}"
             systemd_dropins: "{{ __systemd_dropins }}"
@@ -136,8 +134,7 @@
             scope: "{{ '--system' if item.user == 'root' else '--user' }}"
 
         - name: Run role to enable units
-          include_role:
-            name: linux-system-roles.systemd
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
             systemd_enabled_units: "{{ __systemd_enabled_units }}"
 
@@ -156,8 +153,7 @@
             scope: "{{ '--system' if item.user == 'root' else '--user' }}"
 
         - name: Run role to disable units
-          include_role:
-            name: linux-system-roles.systemd
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
             systemd_disabled_units: "{{ __systemd_disabled_units }}"
 
@@ -176,8 +172,7 @@
             scope: "{{ '--system' if item.user == 'root' else '--user' }}"
 
         - name: Run role to stop units
-          include_role:
-            name: linux-system-roles.systemd
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
             systemd_stopped_units: "{{ __systemd_stopped_units }}"
 
@@ -187,10 +182,9 @@
           loop: "{{ __all_units }}"
 
         - name: Run role to remove unit files and dropins
-          include_role:
-            name: linux-system-roles.systemd
-            public: true
+          include_tasks: tasks/run_role_with_clear_facts.yml
           vars:
+            __sr_public: true
             systemd_unit_files: "{{ __systemd_unit_files |
               map('combine', __absent) | list }}"
             systemd_unit_file_templates: "{{ __systemd_unit_file_templates |