issue #164: add action module to return active strategy.

tests/ansible/ansible.cfg

@@ -2,6 +2,7 @@
 inventory = hosts
 gathering = explicit
 strategy_plugins = ../../ansible_mitogen/plugins/strategy
+action_plugins = lib/action
 library = lib/modules
 retry_files_enabled = False
 forks = 50

tests/ansible/lib/action/determine_strategy.py

@@ -0,0 +1,25 @@
+
+import sys
+
+from ansible.plugins.strategy import StrategyBase
+from ansible.plugins.action import ActionBase
+
+
+class ActionModule(ActionBase):
+    def _get_strategy_name(self):
+        frame = sys._getframe()
+        while frame:
+            st = frame.f_locals.get('self')
+            if isinstance(st, StrategyBase):
+                return '%s.%s' % (type(st).__module__, type(st).__name__)
+            frame = frame.f_back
+        return ''
+
+    def run(self, tmp=None, task_vars=None):
+        return {
+            'changed': False,
+            'ansible_facts': {
+                'strategy': self._get_strategy_name(),
+                'is_mitogen': 'ansible_mitogen' in self._get_strategy_name(),
+            }
+        }