Fix gathering facts in run_once play (#39453)

* Fix gathering facts in run_once play

Fixes https://github.com/ansible/ansible/issues/39312

* Check that run_once doesn't prevent fact gathering

lib/ansible/executor/play_iterator.py

@@ -169,6 +169,9 @@ class PlayIterator:
             fact_path = self._play.fact_path
 
         setup_block = Block(play=self._play)
+        # Gathering facts with run_once would copy the facts from one host to
+        # the others.
+        setup_block.run_once = False
         setup_task = Task(block=setup_block)
         setup_task.action = 'setup'
         setup_task.name = 'Gathering Facts'

test/integration/targets/gathering_facts/runme.sh

@@ -5,3 +5,5 @@ set -eux
 # ANSIBLE_CACHE_PLUGINS=cache_plugins/ ANSIBLE_CACHE_PLUGIN=none ansible-playbook test_gathering_facts.yml -i ../../inventory -v "$@"
 ansible-playbook test_gathering_facts.yml -i ../../inventory -v "$@"
 #ANSIBLE_CACHE_PLUGIN=base ansible-playbook test_gathering_facts.yml -i ../../inventory -v "$@"
+
+ANSIBLE_GATHERING=smart ansible-playbook test_run_once.yml -i ../../inventory -v "$@"

test/integration/targets/gathering_facts/test_run_once.yml

@@ -0,0 +1,28 @@
+---
+- hosts: facthost1
+  gather_facts: no
+  tasks:
+    - name: install test local facts
+      copy:
+        src: uuid.fact
+        dest: /etc/ansible/facts.d/
+        mode: 0755
+
+- hosts: facthost1,facthost2
+  gather_facts: yes
+  run_once: yes
+  tasks:
+    - block:
+      - name: 'Check the same host is used'
+        assert:
+          that: 'hostvars.facthost1.ansible_fqdn == hostvars.facthost2.ansible_fqdn'
+          msg: 'This test requires 2 inventory hosts referring to the same host.'
+      - name: "Check that run_once doesn't prevent fact gathering (#39453)"
+        assert:
+          that: 'hostvars.facthost1.ansible_local.uuid != hostvars.facthost2.ansible_local.uuid'
+          msg: "{{ 'Same value for ansible_local.uuid on both hosts: ' ~ hostvars.facthost1.ansible_local.uuid }}"
+      always:
+        - name: remove test local facts
+          file:
+            path: /etc/ansible/facts.d/uuid.fact
+            state: absent

test/integration/targets/gathering_facts/uuid.fact

@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+
+import json
+import uuid
+
+
+# return a random string
+print(json.dumps(str(uuid.uuid4())))