apache2_module generates false/misleading warning (#5793)

* Add parameter warn_mpm_module to control when warning are raised

* Remoe whitespace

* Add changelog fragment

* Add missing license

* Update changelogs/fragments/5793-apache2-module-npm-warnings.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/apache2_module.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update plugins/modules/apache2_module.py

Co-authored-by: Felix Fontein <felix@fontein.de>

* Update tests/integration/targets/apache2_module/tasks/635-apache2-misleading-warning.yml

Co-authored-by: Felix Fontein <felix@fontein.de>

* Refining integration test - previous was invalid

* False to false

* refactor assertion for suse

* Revert "refactor assertion for suse"

This reverts commit 61b86e7493.

* Excluding test on Suse

Co-authored-by: Felix Fontein <felix@fontein.de>

changelogs/fragments/5793-apache2-module-npm-warnings.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - apache2_module - add module argument ``warn_mpm_absent`` to control whether warning are raised in some edge cases (https://github.com/ansible-collections/community.general/pull/5793).

plugins/modules/apache2_module.py

@@ -49,6 +49,12 @@ options:
         - Ignore configuration checks about inconsistent module configuration. Especially for mpm_* modules.
      type: bool
      default: false
+   warn_mpm_absent:
+     description:
+        - Control the behavior of the warning process for MPM modules.
+     type: bool
+     default: true
+     version_added: 6.3.0
 requirements: ["a2enmod","a2dismod"]
 notes:
   - This does not work on RedHat-based distributions. It does work on Debian- and SuSE-based distributions.
@@ -78,6 +84,18 @@ EXAMPLES = '''
     name: mpm_worker
     ignore_configcheck: true
 
+- name: Disable mpm_event, enable mpm_prefork and ignore warnings about missing mpm module
+  community.general.apache2_module:
+    name: "{{ item.module }}"
+    state: "{{ item.state }}"
+    warn_mpm_absent: false
+    ignore_configcheck: true
+  loop:
+  - module: mpm_event
+    state: absent
+  - module: mpm_prefork
+    state: present
+
 - name: Enable dump_io module, which is identified as dumpio_module inside apache2
   community.general.apache2_module:
     state: present
@@ -140,6 +158,7 @@ def _module_is_enabled(module):
         error_msg = "Error executing %s: %s" % (control_binary, stderr)
         if module.params['ignore_configcheck']:
             if 'AH00534' in stderr and 'mpm_' in module.params['name']:
+                if module.params['warn_mpm_absent']:
                     module.warnings.append(
                         "No MPM module loaded! apache2 reload AND other module actions"
                         " will fail if no MPM module is loaded immediately."
@@ -249,6 +268,7 @@ def main():
             force=dict(type='bool', default=False),
             state=dict(default='present', choices=['absent', 'present']),
             ignore_configcheck=dict(type='bool', default=False),
+            warn_mpm_absent=dict(type='bool', default=True),
         ),
         supports_check_mode=True,
     )

tests/integration/targets/apache2_module/tasks/635-apache2-misleading-warning.yml

@@ -0,0 +1,47 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+# This test represent the misleading behavior of the following issue: https://github.com/ansible-collections/community.general/issues/635
+- name: Disable MPM event module
+  apache2_module:
+    name: "{{ item.module}}"
+    state: "{{ item.state}}"
+    ignore_configcheck: true
+  register: disable_mpm_modules
+  with_items:
+    - { module: mpm_event, state: absent }
+    - { module: mpm_prefork, state: present }
+
+- assert:
+    that:
+    - "'warnings' in disable_mpm_modules"
+    - disable_mpm_modules["warnings"] == [
+      "No MPM module loaded! apache2 reload AND other module actions will fail if no MPM module is loaded immediately.",
+      "No MPM module loaded! apache2 reload AND other module actions will fail if no MPM module is loaded immediately."
+      ]
+
+- name: Enable MPM event module - Revert previous change
+  apache2_module:
+    name: "{{ item.module}}"
+    state: "{{ item.state}}"
+    ignore_configcheck: true
+  register: disable_mpm_modules
+  with_items:
+    - { module: mpm_prefork, state: absent }
+    - { module: mpm_event, state: present }
+
+- name: Disable MPM event module
+  apache2_module:
+    name: "{{ item.module}}"
+    state: "{{ item.state}}"
+    ignore_configcheck: true
+    warn_mpm_absent: false
+  register: disable_mpm_modules
+  with_items:
+    - { module: mpm_event, state: absent }
+    - { module: mpm_prefork, state: present }
+
+- assert:
+    that:
+    - "'warnings' not in disable_mpm_modules"

tests/integration/targets/apache2_module/tasks/actualtest.yml

@@ -180,7 +180,7 @@
       - mpm_worker
       - mpm_event
       - mpm_prefork
-    ignore_errors: yes
+    ignore_errors: true
     register: remove_with_configcheck
 
   - name: ensure configcheck fails task with when run without mpm modules

tests/integration/targets/apache2_module/tasks/main.yml

@@ -45,3 +45,8 @@
         that: modules_before.stdout == modules_after.stdout
   when: ansible_os_family in ['Debian', 'Suse']
   # centos/RHEL does not have a2enmod/a2dismod
+
+- name: include misleading warning test
+  include: 635-apache2-misleading-warning.yml
+  when: ansible_os_family in ['Debian']
+  # Suse has mpm_event module compiled within the base apache2