From 8457949f27d4e9dcc7b377d9cf3ce2b25ef7ef81 2024-02-11 23:12:31
From: Branko Majic <branko@majic.rs>
Date: 2024-02-11 23:12:31
Subject: [PATCH] MAR-154: Improve incorrect Python version handling in virtual environments:

- This should be helpful when performing distribution upgrades as
  well (since it should be able to automatically detect a mismatch
  now).

---

diff --git a/roles/common/tasks/main.yml b/roles/common/tasks/main.yml
index 248ea27ff22857fdd8b1a295abcd8cfbd6862478..d24406fc85c10506d136e5e036c11b7ade43c2ca 100644
--- a/roles/common/tasks/main.yml
+++ b/roles/common/tasks/main.yml
@@ -336,20 +336,31 @@
     home: "/var/lib/pipreqcheck"
     state: present
 
-- name: Check for presence of wrong Python versions
-  stat:
-    path: "{{ item.offending_binary }}"
-  with_items:
-    - offending_binary: "/var/lib/pipreqcheck/virtualenv/bin/python2"
-      virtualenv_directory: "/var/lib/pipreqcheck/virtualenv"
-  register: "pipreqcheck_wrong_python_version_check"
+- name: Retrieve system Python interpreter version
+  command:
+    argv:
+      - "/usr/bin/python3"
+      - "-c"
+      - "import sys; print(sys.version.split(' ')[0])"
+  changed_when: false
+  register: python_interpreter_version
+
+- name: Retrieve virtual environment Python interpreter version (if initialised)
+  command:
+    argv:
+      - "/var/lib/pipreqcheck/virtualenv/bin/python"
+      - "-c"
+      - "import sys; print(sys.version.split(' ')[0])"
+  # Virtual environment perhaps does not exist.
+  failed_when: false
+  changed_when: false
+  register: virtualenv_python_version
 
-- name: Drop Python virtual environment if wrong Python version has been detected within
+- name: Remove virtual environment if Python version does not match
   file:
-    path: "{{ item.item.virtualenv_directory }}"
+    path: "/var/lib/pipreqcheck/virtualenv"
     state: absent
-  when: "item.stat.exists"
-  with_items: "{{ pipreqcheck_wrong_python_version_check.results }}"
+  when: "virtualenv_python_version.rc != 0 or virtualenv_python_version.stdout.strip() != python_interpreter_version.stdout.strip()"
 
 - name: Create directory for Python virtual environment used for installing/running pip-tools
   file:
diff --git a/roles/wsgi_website/molecule/default/tests/test_default.py b/roles/wsgi_website/molecule/default/tests/test_default.py
index 6c3c77eef198ee85b80a568dc099c6268551e1b3..930ff246ace330192242c42b88628491c4b683eb 100644
--- a/roles/wsgi_website/molecule/default/tests/test_default.py
+++ b/roles/wsgi_website/molecule/default/tests/test_default.py
@@ -496,9 +496,9 @@ def test_website_enabled(host, config_file, expected_content):
 
 
 @pytest.mark.parametrize("python_path, expected_version", [
-    ("/var/www/parameters-mandatory/virtualenv/bin/python", "Python 3"),
-    ("/var/www/parameters-optional.local/virtualenv/bin/python", "Python 3"),
-    ("/var/www/parameters-paste-req/virtualenv/bin/python", "Python 3"),
+    ("/var/www/parameters-mandatory/virtualenv/bin/python", "Python 3.9.2"),
+    ("/var/www/parameters-optional.local/virtualenv/bin/python", "Python 3.9.2"),
+    ("/var/www/parameters-paste-req/virtualenv/bin/python", "Python 3.9.2"),
 ])
 def test_python_version_in_virtualenv(host, python_path, expected_version):
     """
diff --git a/roles/wsgi_website/tasks/main.yml b/roles/wsgi_website/tasks/main.yml
index 1510ce6f6e601c20449c1184c76e138e91da2510..9de83d175682f4473b0714f8c19d3af789ec6ccf 100644
--- a/roles/wsgi_website/tasks/main.yml
+++ b/roles/wsgi_website/tasks/main.yml
@@ -81,20 +81,31 @@
   notify:
     - Restart WSGI services
 
-# Ignore failures - the virtual environment might not have been
-# created yet. Don't use --version because Python 2 outputs to stderr,
-# and Python 3 outputs to stdout.
-- name: Check current version of Python used in virtual environment (if any)
-  command: "{{ home }}/virtualenv/bin/python -c \"import sys; print(sys.version.split(' ')[0])\""
+- name: Retrieve requested Python interpreter version
+  command:
+    argv:
+      - "{{ python_interpreter }}"
+      - "-c"
+      - "import sys; print(sys.version.split(' ')[0])"
+  changed_when: false
+  register: python_interpreter_version
+
+- name: Retrieve virtual environment Python interpreter version (if initialised)
+  command:
+    argv:
+      - "{{ home }}/virtualenv/bin/python"
+      - "-c"
+      - "import sys; print(sys.version.split(' ')[0])"
+  # Virtual environment perhaps does not exist.
   failed_when: false
   changed_when: false
-  register: current_python_version
+  register: virtualenv_python_version
 
-- name: Remove existing Python virtual environment (wrong Python version)
+- name: Remove virtual environment if Python version does not match
   file:
     path: "{{ home }}/virtualenv"
     state: absent
-  when: "current_python_version.rc == 0 and not current_python_version.stdout.startswith('3')"
+  when: "virtualenv_python_version.rc != 0 or virtualenv_python_version.stdout.strip() != python_interpreter_version.stdout.strip()"
   notify:
     - Restart WSGI services