Add install_python3 and prepare tasks for python

tests/molecule/resources/inventory/group_vars/all.yml

@@ -6,7 +6,18 @@ selinux_enabled: false
 server_locale: "en_GB.UTF-8"
 
 # mirsg.infrastructure.install_python
-install_python:
+install_python3:
+  version: "3"
+  pip_version: "21.3.1"
+  pip_executable: "pip3"
+  system_packages:
+    - python3
+    - python3-pip
+    - python3-setuptools
+  pip_packages:
+    - cryptography
+
+install_python2:
   version: "2"
   pip_version: "20.3.4"
   pip_executable: "pip"
@@ -17,6 +28,8 @@ install_python:
   pip_packages:
     - cryptography
 
+install_python: "{{ install_python_3 }}" # default to Python 3
+
 # mirsg.infrastructure.firewalld
 allow_public_access: true
 internal_zone_open_services:

tests/molecule/resources/prepare.yml

@@ -17,6 +17,18 @@
             regexp: "^FirewallBackend="
             line: FirewallBackend=iptables
 
+    - name: Check the major Python version for the OS
+      tags: python
+      block:
+        - name: Check default version
+          ansible.builtin.include_role:
+            name: "mirsg.install_python"
+            tasks_from: "check_default_version"
+
+        - name: Set install_python variable based on the version to be installed
+          ansible.builtin.set_fact:
+            install_python: "{{ install_python2 if default_python_version is version('2') else install_python3 }}"
+
     - name: Setup for PostgreSQL
       tags: postgresql
       block: