Respect AZURE_CLIENT_ID, ANSIBLE_AZURE_AUTH_SOURCE on inventory plugin (

#713)

* Attemp to pull environment variables if not set.

* Set ansible azure auth source further upstream

* Updates to documentation

* Update plugins/doc_fragments/azure.py

Co-authored-by: Fred-sun <37327967+Fred-sun@users.noreply.github.com>

* doc_fragments/azure.py Documentation update

* Update plugins/doc_fragments/azure.py

Co-authored-by: Fred-sun <37327967+Fred-sun@users.noreply.github.com>

* Move all logic within azure_rm_common.py

* Removed unused import

* Move back to setting auth source in inventory

---------

Co-authored-by: Fred-sun <37327967+Fred-sun@users.noreply.github.com>

plugins/doc_fragments/azure.py

@@ -34,7 +34,8 @@ class ModuleDocFragment(object):
         type: str
     client_id:
         description:
-            - Azure client ID. Use when authenticating with a Service Principal.
+            - Azure client ID. Use when authenticating with a Service Principal or Managed Identity (msi).
+            - Can also be set via the C(AZURE_CLIENT_ID) environment variable.
         type: str
     secret:
         description:

plugins/inventory/azure_rm.py

@@ -138,6 +138,7 @@
 from ansible.module_utils.parsing.convert_bool import boolean
 from ansible.module_utils._text import to_native, to_bytes, to_text
 from itertools import chain
+from os import environ
 
 try:
     from azure.core._pipeline_client import PipelineClient
@@ -234,8 +235,9 @@ def parse(self, inventory, loader, path, cache=True):
             raise
 
     def _credential_setup(self):
+        auth_source = environ.get('ANSIBLE_AZURE_AUTH_SOURCE', None) or self.get_option('auth_source')
         auth_options = dict(
-            auth_source=self.get_option('auth_source'),
+            auth_source=auth_source,
             profile=self.get_option('profile'),
             subscription_id=self.get_option('subscription_id'),
             client_id=self.get_option('client_id'),

plugins/module_utils/azure_rm_common.py

@@ -1606,6 +1606,7 @@ def _get_msi_credentials(self, subscription_id=None, client_id=None, _cloud_envi
                 except Exception as exc:
                     self.fail("cloud_environment {0} could not be resolved: {1}".format(_cloud_environment, str(exc)), exception=traceback.format_exc())
 
+        client_id = client_id or self._get_env('client_id')
         credential = managed_identity.ManagedIdentityCredential(client_id=client_id, cloud_environment=cloud_environment)
         subscription_id = subscription_id or self._get_env('subscription_id')
         if not subscription_id: