issue #400: add logic to work around AWX callback bug.

ansible_mitogen/loaders.py

@@ -34,6 +34,7 @@ from __future__ import absolute_import
 
 try:
     from ansible.plugins.loader import action_loader
+    from ansible.plugins.loader import callback_loader
     from ansible.plugins.loader import connection_loader
     from ansible.plugins.loader import module_loader
     from ansible.plugins.loader import module_utils_loader
@@ -41,6 +42,7 @@ try:
     from ansible.plugins.loader import strategy_loader
 except ImportError:  # Ansible <2.4
     from ansible.plugins import action_loader
+    from ansible.plugins import callback_loader
     from ansible.plugins import connection_loader
     from ansible.plugins import module_loader
     from ansible.plugins import module_utils_loader

ansible_mitogen/strategy.py

@@ -65,6 +65,29 @@ def wrap_connection_loader__get(name, *args, **kwargs):
     return connection_loader__get(name, *args, **kwargs)
 
 
+def patch_awx_callback():
+    """
+    issue #400: AWX loads a display callback that suffers from thread-safety
+    issues. Detect the presence of older AWX versions and patch the bug.
+    """
+    cls = ansible_mitogen.loaders.callback_loader.get(
+        'awx_display',
+        class_only=True,
+    )
+    if cls is None:  # callback does not exist.
+        return
+
+    # Callback load will have updated sys.path. Now import its guts.
+    try:
+        from awx_display_callback.events import event_context
+    except ImportError:
+        return  # Newer or ancient AWX.
+
+    # Executing this before starting additional threads avoids race.
+    with event_context.set_global():
+        pass
+
+
 class StrategyMixin(object):
     """
     This mix-in enhances any built-in strategy by arranging for various Mitogen
@@ -164,6 +187,7 @@ class StrategyMixin(object):
         ansible_mitogen.process.MuxProcess.start()
         self._add_connection_plugin_path()
         self._install_wrappers()
+        patch_awx_callback()
         try:
             return super(StrategyMixin, self).run(iterator, play_context)
         finally: