Track notified handlers by object rather than simply their name

Due to the fact that roles may be instantiated with different sets of
params (multiple inclusions of the same role or via role dependencies),
simply tracking notified handlers by name does not work. This patch
changes the way we track handler notifications by using the handler
object itself instead of just the name, allowing for multiple internal
instances. Normally this would be bad, but we also modify the way we
search for handlers by first looking at the notifying tasks dependency
chain (ensuring that roles find their own handlers first) and then at
the main list of handlers, using the first match it finds.

This patch also modifies the way we setup the internal list of handlers,
which should allow us to correctly identify if a notified handler exists
more easily.

Fixes #15084

lib/ansible/executor/task_queue_manager.py

@@ -114,13 +114,17 @@ def _initialize_processes(self, num):
         self._result_prc = ResultProcess(self._final_q, self._workers)
         self._result_prc.start()
 
-    def _initialize_notified_handlers(self, handlers):
+    def _initialize_notified_handlers(self, play):
         '''
         Clears and initializes the shared notified handlers dict with entries
         for each handler in the play, which is an empty array that will contain
         inventory hostnames for those hosts triggering the handler.
         '''
 
+        handlers = play.handlers
+        for role in play.roles:
+            handlers.extend(role._handler_blocks)
+
         # Zero the dictionary first by removing any entries there.
         # Proxied dicts don't support iteritems, so we have to use keys()
         for key in self._notified_handlers.keys():
@@ -141,7 +145,8 @@ def _process_block(b):
 
         # then initialize it with the handler names from the handler list
         for handler in handler_list:
-            self._notified_handlers[handler.get_name()] = []
+            if handler not in self._notified_handlers:
+                self._notified_handlers[handler] = []
 
     def load_callbacks(self):
         '''
@@ -226,7 +231,7 @@ def run(self, play):
         self.send_callback('v2_playbook_on_play_start', new_play)
 
         # initialize the shared dictionary containing the notified handlers
-        self._initialize_notified_handlers(new_play.handlers)
+        self._initialize_notified_handlers(new_play)
 
         # load the specified strategy (or the default linear one)
         strategy = strategy_loader.get(new_play.strategy, self)

lib/ansible/playbook/task.py

@@ -105,7 +105,7 @@ def get_path(self):
     def get_name(self):
         ''' return the name of the task '''
 
-        if self._role and self.name:
+        if self._role and self.name and ("%s : " % self._role._role_name) not in self.name:
             return "%s : %s" % (self._role.get_name(), self.name)
         elif self.name:
             return self.name

lib/ansible/plugins/strategy/__init__.py

@@ -318,11 +318,51 @@ def get_original_host(host):
 
                     original_host = get_original_host(task_result._host)
                     original_task = iterator.get_original_task(original_host, task_result._task)
-                    if handler_name not in self._notified_handlers:
-                        self._notified_handlers[handler_name] = []
 
-                    if original_host not in self._notified_handlers[handler_name]:
-                        self._notified_handlers[handler_name].append(original_host)
+                    def search_handler_blocks(handler_blocks):
+                        for handler_block in handler_blocks:
+                            for handler_task in handler_block.block:
+                                handler_vars = self._variable_manager.get_vars(loader=self._loader, play=iterator._play, task=handler_task)
+                                templar = Templar(loader=self._loader, variables=handler_vars)
+                                try:
+                                    # first we check with the full result of get_name(), which may
+                                    # include the role name (if the handler is from a role). If that
+                                    # is not found, we resort to the simple name field, which doesn't
+                                    # have anything extra added to it.
+                                    target_handler_name = templar.template(handler_task.name)
+                                    if target_handler_name == handler_name:
+                                        return handler_task
+                                    else:
+                                        target_handler_name = templar.template(handler_task.get_name())
+                                        if target_handler_name == handler_name:
+                                            return handler_task
+                                except (UndefinedError, AnsibleUndefinedVariable):
+                                    # We skip this handler due to the fact that it may be using
+                                    # a variable in the name that was conditionally included via
+                                    # set_fact or some other method, and we don't want to error
+                                    # out unnecessarily
+                                    continue
+                        return None
+
+                    # Find the handler using the above helper.  First we look up the
+                    # dependency chain of the current task (if it's from a role), otherwise
+                    # we just look through the list of handlers in the current play/all
+                    # roles and use the first one that matches the notify name
+                    target_handler = None
+                    if original_task._role:
+                        target_handler = search_handler_blocks(original_task._role.get_handler_blocks())
+                    if target_handler is None:
+                        target_handler = search_handler_blocks(iterator._play.handlers)
+                    if target_handler is None:
+                        raise AnsibleError("The requested handler '%s' was not found in any of the known handlers" % handler_name)
+
+                    # FIXME: this should be an error now in 2.1+
+                    if target_handler not in self._notified_handlers:
+                        self._notified_handlers[target_handler] = []
+
+                    if original_host not in self._notified_handlers[target_handler]:
+                        self._notified_handlers[target_handler].append(original_host)
+                        # FIXME: should this be a callback?
                         display.vv("NOTIFIED HANDLER %s" % (handler_name,))
 
                 elif result[0] == 'register_host_var':
@@ -572,25 +612,8 @@ def run_handlers(self, iterator, play_context):
             #        but this may take some work in the iterator and gets tricky when
             #        we consider the ability of meta tasks to flush handlers
             for handler in handler_block.block:
-                handler_vars = self._variable_manager.get_vars(loader=self._loader, play=iterator._play, task=handler)
-                templar = Templar(loader=self._loader, variables=handler_vars)
-                try:
-                    # first we check with the full result of get_name(), which may
-                    # include the role name (if the handler is from a role). If that
-                    # is not found, we resort to the simple name field, which doesn't
-                    # have anything extra added to it.
-                    handler_name = templar.template(handler.name)
-                    if handler_name not in self._notified_handlers:
-                        handler_name = templar.template(handler.get_name())
-                except (UndefinedError, AnsibleUndefinedVariable):
-                    # We skip this handler due to the fact that it may be using
-                    # a variable in the name that was conditionally included via
-                    # set_fact or some other method, and we don't want to error
-                    # out unnecessarily
-                    continue
-
-                if handler_name in self._notified_handlers and len(self._notified_handlers[handler_name]):
-                    result = self._do_handler_run(handler, handler_name, iterator=iterator, play_context=play_context)
+                if handler in self._notified_handlers and len(self._notified_handlers[handler]):
+                    result = self._do_handler_run(handler, handler.get_name(), iterator=iterator, play_context=play_context)
                     if not result:
                         break
         return result
@@ -608,7 +631,7 @@ def _do_handler_run(self, handler, handler_name, iterator, play_context, notifie
         handler.name = saved_name
 
         if notified_hosts is None:
-            notified_hosts = self._notified_handlers[handler_name]
+            notified_hosts = self._notified_handlers[handler]
 
         run_once = False
         try:
@@ -671,7 +694,7 @@ def _do_handler_run(self, handler, handler_name, iterator, play_context, notifie
                     continue
 
         # wipe the notification list
-        self._notified_handlers[handler_name] = []
+        self._notified_handlers[handler] = []
         display.debug("done running handlers, result is: %s" % result)
         return result
 

test/units/plugins/strategies/test_strategy_base.py

@@ -171,7 +171,10 @@ def _queue_get(*args, **kwargs):
         mock_tqm._stats = MagicMock()
         mock_tqm._stats.increment.return_value = None
 
+        mock_play = MagicMock()
+
         mock_iterator = MagicMock()
+        mock_iterator._play = mock_play
         mock_iterator.mark_host_failed.return_value = None
         mock_iterator.get_next_task_for_host.return_value = (None, None)
 
@@ -184,6 +187,17 @@ def _queue_get(*args, **kwargs):
         mock_task._role = None
         mock_task.ignore_errors = False
 
+        mock_handler_task = MagicMock(Handler)
+        mock_handler_task.action = 'foo'
+        mock_handler_task.get_name.return_value = "test handler"
+        mock_handler_task.has_triggered.return_value = False
+
+        mock_handler_block = MagicMock()
+        mock_handler_block.block = [mock_handler_task]
+        mock_play.handlers = [mock_handler_block]
+
+        mock_tqm._notified_handlers = {mock_handler_task: []}
+
         mock_group = MagicMock()
         mock_group.add_host.return_value = None
 
@@ -281,8 +295,8 @@ def _get_group(group_name):
         self.assertEqual(len(results), 0)
         self.assertEqual(strategy_base._pending_results, 1)
         self.assertIn('test01', strategy_base._blocked_hosts)
-        self.assertIn('test handler', strategy_base._notified_handlers)
-        self.assertIn(mock_host, strategy_base._notified_handlers['test handler'])
+        self.assertIn(mock_handler_task, strategy_base._notified_handlers)
+        self.assertIn(mock_host, strategy_base._notified_handlers[mock_handler_task])
 
         queue_items.append(('set_host_var', mock_host, mock_task, None, 'foo', 'bar'))
         results = strategy_base._process_pending_results(iterator=mock_iterator)
@@ -379,13 +393,14 @@ def fake_run(*args):
             passwords=None,
         )
         tqm._initialize_processes(3)
+        tqm._initialize_notified_handlers(mock_play)
         tqm.hostvars = dict()
 
         try:
             strategy_base = StrategyBase(tqm=tqm)
 
             strategy_base._inventory = mock_inventory
-            strategy_base._notified_handlers = {"test handler": [mock_host]}
+            strategy_base._notified_handlers = {mock_handler_task: [mock_host]}
 
             task_result = TaskResult(Host('host01'), Handler(), dict(changed=False))
             tqm._final_q.put(('host_task_ok', task_result))