Improve import error handling in azure_rm_common. (ansible#29153)

* Improve import error handling in azure_rm_common.

* Update skip.txt

lib/ansible/module_utils/azure_rm_common.py

@@ -21,11 +21,9 @@
 import re
 import sys
 import copy
-import importlib
 import inspect
 import traceback
 
-from packaging.version import Version
 from os.path import expanduser
 
 from ansible.module_utils.basic import AnsibleModule
@@ -81,6 +79,22 @@
 HAS_MSRESTAZURE = True
 HAS_MSRESTAZURE_EXC = None
 
+try:
+    import importlib
+except ImportError:
+    # This passes the sanity import test, but does not provide a user friendly error message.
+    # Doing so would require catching Exception for all imports of Azure dependencies in modules and module_utils.
+    importlib = None
+
+try:
+    from packaging.version import Version
+    HAS_PACKAGING_VERSION = True
+    HAS_PACKAGING_VERSION_EXC = None
+except ImportError as exc:
+    Version = None
+    HAS_PACKAGING_VERSION = False
+    HAS_PACKAGING_VERSION_EXC = exc
+
 # NB: packaging issue sometimes cause msrestazure not to be installed, check it separately
 try:
     from msrest.serialization import Serializer
@@ -174,6 +188,10 @@ def __init__(self, derived_arg_spec, bypass_checks=False, no_log=False,
                                     supports_check_mode=supports_check_mode,
                                     required_if=merged_required_if)
 
+        if not HAS_PACKAGING_VERSION:
+            self.fail("Do you have packaging installed? Try `pip install packaging`"
+                      "- {0}".format(HAS_PACKAGING_VERSION_EXC))
+
         if not HAS_MSRESTAZURE:
             self.fail("Do you have msrestazure installed? Try `pip install msrestazure`"
                       "- {0}".format(HAS_MSRESTAZURE_EXC))

test/sanity/import/skip.txt

@@ -1,6 +1,6 @@
 lib/ansible/module_utils/ansible_tower.py
 lib/ansible/module_utils/avi.py
-lib/ansible/module_utils/azure_rm_common.py
+lib/ansible/module_utils/ovirt.py
 lib/ansible/modules/cloud/amazon/cloudtrail.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_igw.py
 lib/ansible/modules/cloud/amazon/ec2_vpc_route_table.py