Use templar all the way down

Fixes bugs related to creating Templar() objects on the fly, where
the shared loader objects (serialized to TaskExecutor) aren't used
so information loaded into plugin loaders after forking is lost.

Fixes #11815

lib/ansible/playbook/__init__.py

@@ -26,7 +26,7 @@ from ansible.parsing import DataLoader
 from ansible.playbook.attribute import Attribute, FieldAttribute
 from ansible.playbook.play import Play
 from ansible.playbook.playbook_include import PlaybookInclude
-from ansible.plugins import push_basedir
+from ansible.plugins import get_all_plugin_loaders
 
 
 __all__ = ['Playbook']
@@ -57,8 +57,12 @@ class Playbook:
         # set the loaders basedir
         self._loader.set_basedir(self._basedir)
 
-        # also add the basedir to the list of module directories
-        push_basedir(self._basedir)
+        # dynamically load any plugins from the role directory
+        for name, obj in get_all_plugin_loaders():
+            if obj.subdir:
+                plugin_path = os.path.join(self._basedir, obj.subdir)
+                if os.path.isdir(plugin_path):
+                    obj.add_directory(plugin_path)
 
         ds = self._loader.load_from_file(os.path.basename(file_name))
         if not isinstance(ds, list):

lib/ansible/playbook/role/__init__.py

@@ -37,7 +37,7 @@ from ansible.playbook.helpers import load_list_of_blocks
 from ansible.playbook.role.include import RoleInclude
 from ansible.playbook.role.metadata import RoleMetadata
 from ansible.playbook.taggable import Taggable
-from ansible.plugins import get_all_plugin_loaders, push_basedir
+from ansible.plugins import get_all_plugin_loaders
 from ansible.utils.vars import combine_vars
 
 
@@ -142,8 +142,6 @@ class Role(Base, Become, Conditional, Taggable):
         self._variable_manager = role_include.get_variable_manager()
         self._loader           = role_include.get_loader()
 
-        push_basedir(self._role_path)
-
         if parent_role:
             self.add_parent(parent_role)