Python 3 compatibility error handling: use to_native(e) instead of st…

…r(e) or e.me… (ansible-collections#26)

* Py3 compat error handling: use to_native(e) instead of str(e) or e.message
* PR comment changes, use fail_json_aws and is_boto3_error_code

This commit was initially merged in https://github.com/ansible-collections/community.aws
See: ansible-collections/community.aws@ffe14f9

plugins/modules/ec2_vpc_nat_gateway.py

@@ -204,7 +204,9 @@
 except ImportError:
     pass  # Handled by AnsibleAWSModule
 
+from ansible.module_utils._text import to_native
 from ansible_collections.amazon.aws.plugins.module_utils.core import AnsibleAWSModule
+from ansible_collections.amazon.aws.plugins.module_utils.core import is_boto3_error_code
 from ansible_collections.amazon.aws.plugins.module_utils.ec2 import get_aws_connection_info
 from ansible_collections.amazon.aws.plugins.module_utils.ec2 import boto3_conn
 from ansible_collections.amazon.aws.plugins.module_utils.ec2 import camel_dict_to_snake_dict
@@ -698,13 +700,15 @@ def create(client, subnet_id, allocation_id, client_token=None,
                     'NAT gateway {0} created'.format(result['nat_gateway_id'])
                 )
 
-    except botocore.exceptions.ClientError as e:
-        if "IdempotentParameterMismatch" in e.message:
-            err_msg = (
-                'NAT Gateway does not support update and token has already been provided: ' + str(e)
-            )
-        else:
-            err_msg = str(e)
+    except is_boto3_error_code('IdempotentParameterMismatch'):
+        err_msg = (
+            'NAT Gateway does not support update and token has already been provided: ' + err_msg
+        )
+        success = False
+        changed = False
+        result = None
+    except botocore.exceptions.ClientError as e:  # pylint: disable=duplicate-except
+        err_msg = to_native(e)
         success = False
         changed = False
         result = None

plugins/modules/ec2_vpc_nat_gateway_info.py

@@ -83,6 +83,7 @@
 except ImportError:
     pass  # Handled by AnsibleAWSModule
 
+from ansible.module_utils._text import to_native
 from ansible_collections.amazon.aws.plugins.module_utils.core import AnsibleAWSModule
 from ansible_collections.amazon.aws.plugins.module_utils.ec2 import get_aws_connection_info
 from ansible_collections.amazon.aws.plugins.module_utils.ec2 import boto3_conn
@@ -105,7 +106,7 @@ def get_nat_gateways(client, module, nat_gateway_id=None):
     try:
         result = json.loads(json.dumps(client.describe_nat_gateways(**params), default=date_handler))
     except Exception as e:
-        module.fail_json(msg=str(e.message))
+        module.fail_json(msg=to_native(e))
 
     for gateway in result['NatGateways']:
         # Turn the boto3 result into ansible_friendly_snaked_names