Package facts apt fix (#55963)

* fixes for apt on package_facts

* reverse order, apt is newer

* moved warnings prop to base

changelogs/fragments/package_facts_apt_fix.yml

@@ -0,0 +1,2 @@
+bugfixes:
+    - For package_facts, correct information about apt being missing and fix missing attribute.

lib/ansible/module_utils/facts/packages.py

@@ -18,6 +18,8 @@ def get_all_pkg_managers():
 
 class PkgMgr(with_metaclass(ABCMeta, object)):
 
+    warnings = []
+
     @abstractmethod
     def is_available(self):
         # This method is supposed to return True/False if the package manager is currently installed/usable

lib/ansible/modules/packaging/os/package_facts.py

@@ -155,6 +155,7 @@ ansible_facts:
 
 from ansible.module_utils._text import to_native, to_text
 from ansible.module_utils.basic import AnsibleModule
+from ansible.module_utils.common.process import get_bin_path
 from ansible.module_utils.facts.packages import LibMgr, CLIMgr, get_all_pkg_managers
 
 
@@ -189,6 +190,16 @@ class APT(LibMgr):
         self._cache = self._lib.Cache()
         return self._cache
 
+    def is_available(self):
+        ''' we expect the python bindings installed, but if there is apt/apt-get give warning about missing bindings'''
+        we_have_lib = super(APT, self).is_available()
+        if not we_have_lib:
+            for exe in ('apt', 'apt-get'):
+                if get_bin_path(exe):
+                    self.warnings.append('Found "%s" but python bindings are missing, so we cannot get package information.' % exe)
+                    break
+        return we_have_lib
+
     def list_installed(self):
         return [pk for pk in self.pkg_cache.keys() if self.pkg_cache[pk].is_installed]
 
@@ -299,11 +310,15 @@ def main():
                 if manager.is_available():
                     found += 1
                     packages.update(manager.get_packages())
+
             except Exception as e:
                 if pkgmgr in module.params['manager']:
                     module.warn('Requested package manager %s was not usable by this module: %s' % (pkgmgr, to_text(e)))
                 continue
 
+            for warning in getattr(manager, 'warnings', []):
+                module.warn(warning)
+
         except Exception as e:
             if pkgmgr in module.params['manager']:
                 module.warn('Failed to retrieve packages with %s: %s' % (pkgmgr, to_text(e)))