Implicit flush_handlers inherit play tags (#83968)

changelogs/fragments/skip-handlers-tagged-play.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - "Do not run implicit ``flush_handlers`` meta tasks when the whole play is excluded from the run due to tags specified."

lib/ansible/playbook/play.py

@@ -282,19 +282,30 @@ class Play(Base, Taggable, CollectionSearch):
         roles (which are themselves compiled recursively) and/or the list of
         tasks specified in the play.
         '''
-
         # create a block containing a single flush handlers meta
         # task, so we can be sure to run handlers at certain points
         # of the playbook execution
-        flush_block = Block.load(
-            data={'meta': 'flush_handlers'},
-            play=self,
-            variable_manager=self._variable_manager,
-            loader=self._loader
-        )
-
-        for task in flush_block.block:
-            task.implicit = True
+        flush_block = Block(play=self)
+
+        t = Task()
+        t.action = 'meta'
+        t.resolved_action = 'ansible.builtin.meta'
+        t.args['_raw_params'] = 'flush_handlers'
+        t.implicit = True
+        t.set_loader(self._loader)
+
+        if self.tags:
+            # Avoid calling flush_handlers in case the whole play is skipped on tags,
+            # this could be performance improvement since calling flush_handlers on
+            # large inventories could be expensive even if no hosts are notified
+            # since we call flush_handlers per host.
+            # Block.filter_tagged_tasks ignores evaluating tags on implicit meta
+            # tasks so we need to explicitly call Task.evaluate_tags here.
+            t.tags = self.tags
+            if t.evaluate_tags(self.only_tags, self.skip_tags, all_vars=self.vars):
+                flush_block.block = [t]
+        else:
+            flush_block.block = [t]
 
         block_list = []
         if self.force_handlers:

lib/ansible/plugins/strategy/__init__.py

@@ -1090,8 +1090,10 @@ class StrategyBase:
         else:
             result['changed'] = False
 
-        if not task.implicit:
         header = skip_reason if skipped else msg
+        if task.implicit:
+            display.debug(f"META: {header}")
+        else:
             display.vv(f"META: {header}")
 
         res = TaskResult(target_host, task, result)

test/integration/targets/handlers/runme.sh

@@ -228,3 +228,7 @@ ansible-playbook handler_notify_earlier_handler.yml "$@" 2>&1 | tee out.txt
 [ "$(grep out.txt -ce 'h2_ran')" = "1" ]
 [ "$(grep out.txt -ce 'h3_ran')" = "1" ]
 [ "$(grep out.txt -ce 'h4_ran')" = "1" ]
+
+ANSIBLE_DEBUG=1 ansible-playbook tagged_play.yml --skip-tags the_whole_play "$@" 2>&1 | tee out.txt
+[ "$(grep out.txt -ce 'META: triggered running handlers')" = "0" ]
+[ "$(grep out.txt -ce 'handler_ran')" = "0" ]

test/integration/targets/handlers/tagged_play.yml

@@ -0,0 +1,10 @@
+- hosts: localhost
+  gather_facts: false
+  tags: the_whole_play
+  tasks:
+    - command: echo
+      notify: h
+  handlers:
+    - name: h
+      debug:
+        msg: handler_ran