Address compat issue for collection loading on py26 (#68219)

* Address compat issue for collection loading on py26

* Move import_module shim to utils for compat across the codebase

* Enable collection tests on py2.6

* Update changelog fragment

* Simplify code using sys.moduls

* Move compat to module_utils/compat/importlib

* Add back errantly deleted newline

* Remove hack comment

Co-Authored-By: Matt Clay <matt@mystile.com>

Co-authored-by: Matt Clay <matt@mystile.com>

changelogs/fragments/py26-collection-loader.yml

@@ -0,0 +1,2 @@
+bugfixes:
+- Create an ``import_module`` compat util, for use across the codebase, to allow collection loading to work properly on Python26

lib/ansible/executor/module_common.py

@@ -37,6 +37,7 @@ 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._text import to_bytes, to_text, to_native
+from ansible.module_utils.compat.importlib import import_module
 from ansible.plugins.loader import module_utils_loader
 # Must import strategy and use write_locks from there
 # If we import write_locks directly then we end up binding a
@@ -53,13 +54,6 @@ try:
 except ImportError:
     import imp
 
-
-# HACK: keep Python 2.6 controller tests happy in CI until they're properly split
-try:
-    from importlib import import_module
-except ImportError:
-    import_module = __import__
-
 # if we're on a Python that doesn't have FNFError, redefine it as IOError (since that's what we'll see)
 try:
     FileNotFoundError

lib/ansible/executor/powershell/module_manifest.py

@@ -14,15 +14,10 @@ import re
 
 from distutils.version import LooseVersion
 
-# HACK: keep Python 2.6 controller tests happy in CI until they're properly split
-try:
-    from importlib import import_module
-except ImportError:
-    import_module = __import__
-
 from ansible import constants as C
 from ansible.errors import AnsibleError
 from ansible.module_utils._text import to_bytes, to_native, to_text
+from ansible.module_utils.compat.importlib import import_module
 from ansible.plugins.loader import ps_module_utils_loader
 
 

lib/ansible/module_utils/compat/importlib.py

@@ -0,0 +1,18 @@
+# Copyright (c) 2020 Matt Martz <matt@sivel.net>
+# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
+
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
+import sys
+
+try:
+    from importlib import import_module
+except ImportError:
+    # importlib.import_module returns the tail
+    # whereas __import__ returns the head
+    # compat to work like importlib.import_module
+    def import_module(name):
+        __import__(name)
+        return sys.modules[name]

lib/ansible/plugins/loader.py

@@ -18,6 +18,7 @@ from collections import defaultdict
 from ansible import constants as C
 from ansible.errors import AnsibleError
 from ansible.module_utils._text import to_bytes, to_text, to_native
+from ansible.module_utils.compat.importlib import import_module
 from ansible.module_utils.six import string_types
 from ansible.parsing.utils.yaml import from_yaml
 from ansible.parsing.yaml.loader import AnsibleLoader
@@ -32,12 +33,6 @@ try:
 except ImportError:
     import imp
 
-# HACK: keep Python 2.6 controller tests happy in CI until they're properly split
-try:
-    from importlib import import_module
-except ImportError:
-    import_module = __import__
-
 display = Display()
 
 

lib/ansible/template/__init__.py

@@ -45,6 +45,7 @@ from ansible.module_utils.six import iteritems, string_types, text_type
 from ansible.module_utils._text import to_native, to_text, to_bytes
 from ansible.module_utils.common._collections_compat import Sequence, Mapping, MutableMapping
 from ansible.module_utils.common.collections import is_sequence
+from ansible.module_utils.compat.importlib import import_module
 from ansible.plugins.loader import filter_loader, lookup_loader, test_loader
 from ansible.template.safe_eval import safe_eval
 from ansible.template.template import AnsibleJ2Template
@@ -53,12 +54,6 @@ from ansible.utils.collection_loader import AnsibleCollectionRef
 from ansible.utils.display import Display
 from ansible.utils.unsafe_proxy import wrap_var
 
-# HACK: keep Python 2.6 controller tests happy in CI until they're properly split
-try:
-    from importlib import import_module
-except ImportError:
-    import_module = __import__
-
 display = Display()
 
 

lib/ansible/utils/collection_loader.py

@@ -13,15 +13,10 @@ import sys
 from types import ModuleType
 
 from ansible.module_utils._text import to_bytes, to_native, to_text
+from ansible.module_utils.compat.importlib import import_module
 from ansible.module_utils.six import iteritems, string_types, with_metaclass
 from ansible.utils.singleton import Singleton
 
-# HACK: keep Python 2.6 controller tests happy in CI until they're properly split
-try:
-    from importlib import import_module
-except ImportError:
-    import_module = __import__
-
 _SYNTHETIC_PACKAGES = {
     # these provide fallback package definitions when there are no on-disk paths
     'ansible_collections': dict(type='pkg_only', allow_external_subpackages=True),

test/integration/targets/collections/aliases

@@ -1,5 +1,4 @@
 posix
 shippable/posix/group4
 shippable/windows/group1
-skip/python2.6
 windows

test/integration/targets/collections_plugin_namespace/aliases

@@ -1,2 +1 @@
 shippable/posix/group1
-skip/python2.6

test/integration/targets/collections_relative_imports/aliases

@@ -1,2 +1 @@
 shippable/posix/group1
-skip/python2.6