From 02c21742a3a5f12180afe8fae3d45a023f40f715 Mon Sep 17 00:00:00 2001
From: Brian Coca <bcoca@users.noreply.github.com>
Date: Thu, 12 Jun 2025 12:13:15 -0400
Subject: [PATCH] Assemble add check mode (#85094)

Co-authored-by: Abhijeet Kasurde <akasurde@redhat.com>
---
 changelogs/fragments/assemble_check_mode.yml  |  3 ++
 lib/ansible/module_utils/basic.py             |  9 ++---
 lib/ansible/modules/assemble.py               |  8 +++--
 lib/ansible/plugins/action/assemble.py        |  3 +-
 .../targets/assemble/tasks/main.yml           | 36 +++++++++++++++++--
 5 files changed, 48 insertions(+), 11 deletions(-)
 create mode 100644 changelogs/fragments/assemble_check_mode.yml

diff --git a/changelogs/fragments/assemble_check_mode.yml b/changelogs/fragments/assemble_check_mode.yml
new file mode 100644
index 00000000000..b90dd7ecb8f
--- /dev/null
+++ b/changelogs/fragments/assemble_check_mode.yml
@@ -0,0 +1,3 @@
+minor_changes:
+  - assemble action added check_mode support
+  - module_utils.basic.backup_local enforces check_mode now
diff --git a/lib/ansible/module_utils/basic.py b/lib/ansible/module_utils/basic.py
index cd8ee202200..9208a4c9134 100644
--- a/lib/ansible/module_utils/basic.py
+++ b/lib/ansible/module_utils/basic.py
@@ -1657,10 +1657,11 @@ class AnsibleModule(object):
             ext = time.strftime("%Y-%m-%d@%H:%M:%S~", time.localtime(time.time()))
             backupdest = '%s.%s.%s' % (fn, os.getpid(), ext)
 
-            try:
-                self.preserved_copy(fn, backupdest)
-            except (shutil.Error, OSError) as ex:
-                raise Exception(f'Could not make backup of {fn!r} to {backupdest!r}.') from ex
+            if not self.check_mode:
+                try:
+                    self.preserved_copy(fn, backupdest)
+                except (shutil.Error, IOError) as ex:
+                    raise Exception(f'Could not make backup of {fn!r} to {backupdest!r}.') from ex
 
         return backupdest
 
diff --git a/lib/ansible/modules/assemble.py b/lib/ansible/modules/assemble.py
index 11dd8ab6030..b1329496d96 100644
--- a/lib/ansible/modules/assemble.py
+++ b/lib/ansible/modules/assemble.py
@@ -80,7 +80,7 @@ attributes:
     bypass_host_loop:
       support: none
     check_mode:
-      support: none
+      support: full
     diff_mode:
       support: full
     platform:
@@ -212,6 +212,7 @@ def main():
             decrypt=dict(type='bool', default=True),
         ),
         add_file_common_args=True,
+        supports_check_mode=True,
     )
 
     changed = False
@@ -266,12 +267,13 @@ def main():
         if backup and dest_hash is not None:
             result['backup_file'] = module.backup_local(dest)
 
-        module.atomic_move(path, dest, unsafe_writes=module.params['unsafe_writes'])
+        if not module.check_mode:
+            module.atomic_move(path, dest, unsafe_writes=module.params['unsafe_writes'])
         changed = True
 
     cleanup(module, path, result)
 
-    # handle file permissions
+    # handle file permissions (check mode aware)
     file_args = module.load_file_common_arguments(module.params)
     result['changed'] = module.set_fs_attributes_if_different(file_args, changed)
 
diff --git a/lib/ansible/plugins/action/assemble.py b/lib/ansible/plugins/action/assemble.py
index 344f8f00d8e..4d8bdc00df4 100644
--- a/lib/ansible/plugins/action/assemble.py
+++ b/lib/ansible/plugins/action/assemble.py
@@ -81,9 +81,10 @@ class ActionModule(ActionBase):
 
     def run(self, tmp=None, task_vars=None):
 
-        self._supports_check_mode = False
+        self._supports_check_mode = True
 
         super(ActionModule, self).run(tmp, task_vars)
+
         del tmp  # tmp no longer has any effect
 
         if task_vars is None:
diff --git a/test/integration/targets/assemble/tasks/main.yml b/test/integration/targets/assemble/tasks/main.yml
index add95f936d0..a0e90b63277 100644
--- a/test/integration/targets/assemble/tasks/main.yml
+++ b/test/integration/targets/assemble/tasks/main.yml
@@ -29,16 +29,46 @@
     that:
     - "result.changed == true"
 
-- name: test assemble with all fragments
+- name: test assemble with all fragments, but only check!
   assemble: src="{{remote_tmp_dir}}/src" dest="{{remote_tmp_dir}}/assembled1"
+  check_mode: True
   register: result
 
 - name: assert the fragments were assembled
   assert:
     that:
-    - "result.state == 'file'"
     - "result.changed == True"
-    - "result.checksum == '74152e9224f774191bc0bedf460d35de86ad90e6'"
+
+- name: ensure file was not created
+  stat:
+    path: "{{remote_tmp_dir}}/assembled1"
+  register: check_it
+
+- name: it should not exist, yet
+  assert:
+    that:
+      - not check_it.stat.exists
+
+- name: test assemble with all fragments, really create now!
+  assemble: src="{{remote_tmp_dir}}/src" dest="{{remote_tmp_dir}}/assembled1"
+  register: result2
+
+- name: assert the fragments were assembled
+  assert:
+    that:
+    - "result2.state == 'file'"
+    - "result2.changed == True"
+    - "result2.checksum == '74152e9224f774191bc0bedf460d35de86ad90e6'"
+
+- name: ensure file was created
+  stat:
+    path: "{{remote_tmp_dir}}/assembled1"
+  register: check_it2
+
+- name: it should exist now
+  assert:
+    that:
+      - check_it2.stat.exists
 
 - name: test assemble with all fragments
   assemble: src="{{remote_tmp_dir}}/src" dest="{{remote_tmp_dir}}/assembled1"