pass iam_role_arn through to aws inv. plugin

awx/main/models/inventory.py

@@ -2027,6 +2027,9 @@ class ec2(PluginFileInjector):
                 grouping_data['key'] += ' | regex_replace("{rx}", "_")'.format(rx=legacy_regex)
         # end compatibility content
 
+        if source_vars.get('iam_role_arn', None):
+            ret['iam_role_arn'] = source_vars['iam_role_arn']
+
         # This was an allowed ec2.ini option, also plugin option, so pass through
         if source_vars.get('boto_profile', None):
             ret['boto_profile'] = source_vars['boto_profile']

awx/main/tests/data/inventory/plugins/ec2/files/aws_ec2.yml

@@ -1,4 +1,5 @@
 boto_profile: /tmp/my_boto_stuff
+iam_role_arn: arn:aws:iam::123456789012:role/test-role
 compose:
   ansible_host: public_ip_address
   ec2_account_id: owner_id

awx/main/tests/functional/test_inventory_source_injectors.py

@@ -38,7 +38,8 @@ TEST_SOURCE_FIELDS = {
 
 INI_TEST_VARS = {
     'ec2': {
-        'boto_profile': '/tmp/my_boto_stuff'
+        'boto_profile': '/tmp/my_boto_stuff',
+        'iam_role_arn': 'arn:aws:iam::123456789012:role/test-role'
     },
     'gce': {},
     'openstack': {