Add ansible_parent_role_names magic variable (#46687)

-Add: Test cases for ansible_parent_role_names and ansible_parent_role_paths
-Add: ansible_parent_role_names/paths variables for when a role is being included by another role.

test/integration/targets/include_parent_role_vars/aliases

@@ -0,0 +1,2 @@
+# Continuation of special_vars integration tests to test special variables set on role inclusion.
+hidden

test/integration/targets/include_parent_role_vars/tasks/included_by_other_role.yml

@@ -0,0 +1,37 @@
+# Copyright 2019 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+- name: ensure our parent role tree to contain only our direct parent item
+  assert:
+    that:
+      - "ansible_parent_role_names == ['special_vars']"
+
+- name: ensure that ansible_parent_role_paths has the same length as ansible_parent_role_names
+  assert:
+    that:
+      - "ansible_parent_role_names|length == ansible_parent_role_paths|length"
+
+- name: attempt to import ourselves
+  import_role:
+    name: "include_parent_role_vars"
+    tasks_from: "included_by_ourselves.yml"
+
+- name: ensure our parent role tree to contain only our direct parent item after importing
+  assert:
+    that:
+      - "ansible_parent_role_names == ['special_vars']"
+
+- name: attempt to include ourselves
+  include_role:
+    name: "include_parent_role_vars"
+    tasks_from: "included_by_ourselves.yml"
+
+- name: ensure our parent role tree to contain only our direct parent item after including
+  assert:
+    that:
+      - "ansible_parent_role_names == ['special_vars']"
+
+- name: ensure that ansible_parent_role_paths has the same length as ansible_parent_role_names
+  assert:
+    that:
+      - "ansible_parent_role_names|length == ansible_parent_role_paths|length"

test/integration/targets/include_parent_role_vars/tasks/included_by_ourselves.yml

@@ -0,0 +1,14 @@
+# Copyright 2019 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+- name: check if the inclusion tree shows ourself twice as well as our initial parent
+  assert:
+    that:
+      - "ansible_parent_role_names|length == 2"
+      - "ansible_parent_role_names[0] == 'include_parent_role_vars'"  # Since we included ourselves, we're the top level
+      - "ansible_parent_role_names[1] == 'special_vars'"
+
+- name: ensure that ansible_parent_role_paths has the same length as ansible_parent_role_names
+  assert:
+    that:
+      - "ansible_parent_role_names|length == ansible_parent_role_paths|length"

test/integration/targets/include_parent_role_vars/tasks/main.yml

@@ -0,0 +1,21 @@
+# Copyright 2019 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+
+- name: ensure our parent role tree to contain only our direct parent item
+  assert:
+    that:
+      - "ansible_parent_role_names == ['special_vars']"
+
+- name: ensure that ansible_parent_role_paths has the same length as ansible_parent_role_names
+  assert:
+    that:
+      - "ansible_parent_role_names|length == ansible_parent_role_paths|length"
+
+# task importing should not affect ansible_parent_role_names
+- name: test task-importing after we've been included by another role
+  import_tasks: "included_by_other_role.yml"
+
+# task inclusion should not affect ansible_parent_role_names
+- name: test task-inclusion after we've been included by another role
+  include_tasks: "included_by_other_role.yml"

test/integration/targets/special_vars/aliases

@@ -1 +1,2 @@
 shippable/posix/group2
+needs/target/include_parent_role_vars

test/integration/targets/special_vars/tasks/main.yml

@@ -56,3 +56,45 @@
   assert:
     that:
       - "(ansible_play_role_names + ansible_dependent_role_names)|unique|sort|list == ansible_role_names|sort|list"
+
+- name: check that ansible_parent_role_names is normally unset when not included/imported (before including other roles)
+  assert:
+    that:
+      - "ansible_parent_role_names is undefined"
+      - "ansible_parent_role_paths is undefined"
+
+- name: ansible_parent_role_names - test functionality by including another role
+  include_role:
+    name: include_parent_role_vars
+    tasks_from: included_by_other_role.yml
+
+- name: check that ansible_parent_role_names is normally unset when not included/imported (after including other role)
+  assert:
+    that:
+      - "ansible_parent_role_names is undefined"
+      - "ansible_parent_role_paths is undefined"
+
+- name: ansible_parent_role_names - test functionality by importing another role
+  import_role:
+    name: include_parent_role_vars
+    tasks_from: included_by_other_role.yml
+
+- name: check that ansible_parent_role_names is normally unset when not included/imported (after importing other role)
+  assert:
+    that:
+      - "ansible_parent_role_names is undefined"
+      - "ansible_parent_role_paths is undefined"
+
+- name: ansible_parent_role_names - test functionality by including another role
+  include_role:
+    name: include_parent_role_vars
+
+- name: check that ansible_parent_role_names is normally unset when not included/imported (after both import and inlcude)
+  assert:
+    that:
+      - "ansible_parent_role_names is undefined"
+      - "ansible_parent_role_paths is undefined"
+
+- name: ansible_parent_role_names - test functionality by importing another role
+  import_role:
+    name: include_parent_role_vars