module_common - handle cache directory creation collision (#75106)

* module_common - handle cache directory creation collision

Occasionally multiple workers can try to create the cache directory if it exists. Catch the exception
and handle it.

* Just re-raise if it doesn't exist rather than trying again

* Use exists_ok rather than handling an exception

* Remove unused import and unused variable

* Go back to try/except but with OSError

Since we do not have split controller remote, this needs to be able to run in Python 2 in order
to be merged currently.

changelogs/fragments/concurrency-cache-dir-collision.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - module_common - handle exception when multiple workers try to create the cache directory

lib/ansible/executor/module_common.py

@@ -34,7 +34,7 @@ from io import BytesIO
 
 from ansible.release import __version__, __author__
 from ansible import constants as C
-from ansible.errors import AnsibleError, AnsiblePluginRemovedError
+from ansible.errors import AnsibleError
 from ansible.executor.interpreter_discovery import InterpreterDiscoveryRequiredError
 from ansible.executor.powershell import module_manifest as ps_manifest
 from ansible.module_utils.common.json import AnsibleJSONEncoder
@@ -1115,7 +1115,6 @@ def _find_module_utils(module_name, b_module_data, module_path, module_args, tas
         return b_module_data, module_style, shebang
 
     output = BytesIO()
-    py_module_names = set()
 
     try:
         remote_module_fqn = _get_ansible_module_fqn(module_path)
@@ -1185,10 +1184,19 @@ def _find_module_utils(module_name, b_module_data, module_path, module_args, tas
                     # Write the assembled module to a temp file (write to temp
                     # so that no one looking for the file reads a partially
                     # written file)
+                    #
+                    # FIXME: Once split controller/remote is merged, this can be simplified to
+                    #        os.makedirs(lookup_path, exist_ok=True)
                     if not os.path.exists(lookup_path):
+                        try:
                             # Note -- if we have a global function to setup, that would
                             # be a better place to run this
                             os.makedirs(lookup_path)
+                        except OSError:
+                            # Multiple processes tried to create the directory. If it still does not
+                            # exist, raise the original exception.
+                            if not os.path.exists(lookup_path):
+                                raise
                     display.debug('ANSIBALLZ: Writing module')
                     with open(cached_module_filename + '-part', 'wb') as f:
                         f.write(zipdata)