Use ansible_facts to reference facts

By default, Ansible injects a variable for every fact, prefixed with
ansible_. This can result in a large number of variables for each host,
which at scale can incur a performance penalty. Ansible provides a
configuration option [0] that can be set to False to prevent this
injection of facts. In this case, facts should be referenced via
ansible_facts.<fact>.

This change updates all references to Ansible facts from using
individual fact variables to using the items in the
ansible_facts dictionary. This allows users to disable fact variable
injection in their Ansible configuration, which may provide some
performance improvement.

[0] https://docs.ansible.com/ansible/latest/reference_appendices/config.html#inject-facts-as-vars

defaults/main.yml

@@ -66,7 +66,7 @@ libvirt_host_uri: >-
 
 # Whether the python3 version of the libvirt python bindings should be
 # installed. If false, the python 2 bindings will be installed.
-libvirt_host_python3: "{{ ansible_python.version.major == 3 }}"
+libvirt_host_python3: "{{ ansible_facts.python.version.major == 3 }}"
 
 # Whether to install and enable the libvirt daemon.
 libvirt_host_install_daemon: true

tasks/install-daemon.yml

@@ -31,7 +31,7 @@
   retries: 3
   become: True
   when:
-    - ansible_os_family == "RedHat"
+    - ansible_facts.os_family == "RedHat"
     - libvirt_host_qemu_emulators | length > 0
 
 - name: Ensure QEMU emulator packages are installed
@@ -40,7 +40,7 @@
     state: present
   loop: "{{ libvirt_host_qemu_emulators | flatten(levels=1) }}"
   # NOTE(mgoddard): CentOS 8 does not provide separate packages per-emulator.
-  when: ansible_os_family != "RedHat" or ansible_distribution_major_version | int == 7
+  when: ansible_facts.os_family != "RedHat" or ansible_facts.distribution_major_version | int == 7
   register: result
   until: result is success
   retries: 3

tasks/main.yml

@@ -11,8 +11,8 @@
   include: "{{ post_install_path }}"
   with_first_found:
     - files:
-        - post-install-{{ ansible_distribution }}.yml
-        - post-install-{{ ansible_os_family }}.yml
+        - post-install-{{ ansible_facts.distribution }}.yml
+        - post-install-{{ ansible_facts.os_family }}.yml
       skip: true
   loop_control:
     loop_var: post_install_path

tasks/post-install-Debian.yml

@@ -34,7 +34,7 @@
   become: true
   when:
     - libvirt_host_install_daemon | bool
-    - ansible_apparmor.status | default == 'enabled'
+    - ansible_facts.apparmor.status | default == 'enabled'
     - item.type == "dir"
   loop: "{{ libvirt_host_pools | flatten(levels=1) }}"
   notify:

tasks/prelude.yml

@@ -4,7 +4,7 @@
 - name: gather os specific variables
   include_vars: "{{ item }}"
   with_first_found:
-    - "{{ ansible_distribution }}-{{ ansible_distribution_major_version }}.yml"
-    - "{{ ansible_distribution }}.yml"
-    - "{{ ansible_os_family }}.yml"
+    - "{{ ansible_facts.distribution }}-{{ ansible_facts.distribution_major_version }}.yml"
+    - "{{ ansible_facts.distribution }}.yml"
+    - "{{ ansible_facts.os_family }}.yml"
   tags: vars

vars/Debian.yml

@@ -6,12 +6,12 @@ libvirt_host_libvirt_packages_common:
 # List of all daemon packages to install.
 libvirt_host_libvirt_packages_libvirt_daemon:
   # The apparmor package contains the apparmor_parser tool.
-  - "{% if ansible_apparmor.status| default == 'enabled' %}apparmor{% endif %}"
+  - "{% if ansible_facts.apparmor.status| default == 'enabled' %}apparmor{% endif %}"
   - >-
-    {%- if (ansible_distribution == "Ubuntu" and
-            ansible_distribution_major_version is version_compare('16.04', '<')) or
-           (ansible_distribution == "Debian" and
-            ansible_distribution_major_version is version_compare('8', '<')) -%}
+    {%- if (ansible_facts.distribution == "Ubuntu" and
+            ansible_facts.distribution_major_version is version_compare('16.04', '<')) or
+           (ansible_facts.distribution == "Debian" and
+            ansible_facts.distribution_major_version is version_compare('8', '<')) -%}
     libvirt-bin
     {%- else -%}
     libvirt-daemon-system