Change ANSIBLE_LIBRARY PATH processing (#3137)

When the environment variable ANSIBLE_LIBRARY is used, molecule is
currently extending the path with the contents of the found variable,
however, this will cause problems as the system driven path will
conflict with a user defined path. To correct this issue the path
processing will now insert the user provided variable into the path.

Lanuch-Pad: https://bugs.launchpad.net/tripleo/+bug/1930757
Signed-off-by: Kevin Carter <kecarter@redhat.com>

src/molecule/provisioner/ansible.py

@@ -915,7 +915,13 @@ def _get_modules_directories(self):
 
         Adds modules directory from molecule and its plugins.
         """
-        paths = [util.abs_path(os.path.join(self._get_plugin_directory(), "modules"))]
+        paths = list()
+        if os.environ.get("ANSIBLE_LIBRARY"):
+            paths = list(map(util.abs_path, os.environ["ANSIBLE_LIBRARY"].split(":")))
+
+        paths.append(
+            util.abs_path(os.path.join(self._get_plugin_directory(), "modules"))
+        )
 
         for d in drivers():
             p = d.modules_dir()
@@ -939,9 +945,6 @@ def _get_modules_directories(self):
             ]
         )
 
-        if os.environ.get("ANSIBLE_LIBRARY"):
-            paths.extend(map(util.abs_path, os.environ["ANSIBLE_LIBRARY"].split(":")))
-
         return paths
 
     def _get_filter_plugin_directory(self):

src/molecule/test/unit/provisioner/test_ansible.py

@@ -704,7 +704,7 @@ def test_get_modules_directories_single_ansible_library(_instance, monkeypatch):
     paths = _instance._get_modules_directories()
 
     assert len(paths) == 6
-    assert paths[-1] == "/abs/path/lib"
+    assert paths[0] == "/abs/path/lib"
 
 
 def test_get_modules_directories_multi_ansible_library(_instance, monkeypatch):
@@ -713,8 +713,8 @@ def test_get_modules_directories_multi_ansible_library(_instance, monkeypatch):
     paths = _instance._get_modules_directories()
 
     assert len(paths) == 7
-    assert paths[-2].endswith("relpath/lib")
-    assert paths[-1] == "/abs/path/lib"
+    assert paths[0].endswith("relpath/lib")
+    assert paths[1] == "/abs/path/lib"
 
 
 def test_get_filter_plugin_directory(_instance):