Fix templating task action with host-specific vars (#75600)

Fixes #75568

changelogs/fragments/75568-fix-templating-task-action-host-specific-vars.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - Fix templating task action with host-specific vars (https://github.com/ansible/ansible/issues/75568)

lib/ansible/plugins/strategy/linear.py

@@ -263,16 +263,16 @@ class StrategyModule(StrategyBase):
                     # sets BYPASS_HOST_LOOP to true, or if it has run_once enabled. If so, we
                     # will only send this task to the first host in the list.
 
-                    task.action = templar.template(task.action)
+                    task_action = templar.template(task.action)
 
                     try:
-                        action = action_loader.get(task.action, class_only=True, collection_list=task.collections)
+                        action = action_loader.get(task_action, class_only=True, collection_list=task.collections)
                     except KeyError:
                         # we don't care here, because the action may simply not have a
                         # corresponding action plugin
                         action = None
 
-                    if task.action in C._ACTION_META:
+                    if task_action in C._ACTION_META:
                         # for the linear strategy, we run meta tasks just once and for
                         # all hosts currently being iterated over rather than one host
                         results.extend(self._execute_meta(task, play_context, iterator, host))

test/integration/targets/strategy_linear/inventory

@@ -1,3 +1,3 @@
 [local]
-testhost ansible_connection=local
-testhost2 ansible_connection=local
+testhost ansible_connection=local ansible_python_interpreter="{{ ansible_playbook_python }}"
+testhost2 ansible_connection=local ansible_python_interpreter="{{ ansible_playbook_python }}"

test/integration/targets/strategy_linear/runme.sh

@@ -3,3 +3,5 @@
 set -eux
 
 ansible-playbook test_include_file_noop.yml -i inventory "$@"
+
+ansible-playbook task_action_templating.yml -i inventory "$@"

test/integration/targets/strategy_linear/task_action_templating.yml

@@ -0,0 +1,26 @@
+- hosts: testhost,testhost2
+  gather_facts: no
+  tasks:
+    - set_fact:
+        module_to_run: 'debug'
+      when: inventory_hostname == 'testhost'
+
+    - set_fact:
+        module_to_run: 'ping'
+      when: inventory_hostname == 'testhost2'
+
+    - action:
+        module: '{{ module_to_run }}'
+      register: out
+
+    - assert:
+        that:
+          - "'msg' in out"
+          - "'ping' not in out"
+      when: inventory_hostname == 'testhost'
+
+    - assert:
+        that:
+          - "'ping' in out"
+          - "'msg' not in out"
+      when: inventory_hostname == 'testhost2'