Fix Create missing and implement StackSet Create Missing support

formica/cli.py

@@ -278,6 +278,7 @@ def stack_set_parser(parser):
     add_stack_set_operation_preferences(update_parser)
     add_organization_account_template_variables(update_parser)
     add_yes_parameter(update_parser)
+    add_create_missing_argument(update_parser)
     update_parser.set_defaults(func=stack_set.update_stack_set)
 
     # Remove
@@ -569,14 +570,15 @@ def change(args):
     change_set = ChangeSet(stack=args.stack, client=client)
 
     change_set_type = "UPDATE"
-    try:
-        client.describe_stacks(StackName=args.stack)
-    except ClientError as e:
-        error = e.response["Error"]
-        if error["Code"] == "ValidationError" and "does not exist" in error["Message"]:
-            change_set_type = "CREATE"
-        else:
-            raise e
+    if args.create_missing:
+        try:
+            client.describe_stacks(StackName=args.stack)
+        except ClientError as e:
+            error = e.response["Error"]
+            if error["Code"] == "ValidationError" and "does not exist" in error["Message"]:
+                change_set_type = "CREATE"
+            else:
+                raise e
 
     change_set.create(
         template=loader.template(indent=None),

formica/stack_set.py

@@ -1,6 +1,7 @@
 import logging
 import sys
 import time
+from botocore.exceptions import ClientError
 
 from .aws import AWS
 from .helper import collect_vars, main_account_id, aws_accounts, aws_regions
@@ -46,13 +47,25 @@ def ack(message):
 
 @requires_stack_set
 def update_stack_set(args):
+    if args.create_missing:
+        client = AWS.current_session().client("cloudformation")
+        try:
+            client.describe_stack_set(StackSetName=args.stack_set)
+        except ClientError as e:
+            if e.response["Error"]["Code"] == "StackSetNotFoundException":
+                create_stack_set(args)
+                return
+            else:
+                raise e
+
     compare_stack_set(
         stack=args.stack_set,
         vars=collect_vars(args),
         parameters=args.parameters,
         tags=args.tags,
         main_account_parameter=args.main_account_parameter,
     )
+
     if args.yes or ack("Do you want to update the StackSet with above changes"):
         __manage_stack_set(args=args, create=False)
     else:

tests/unit/test_change.py

@@ -117,6 +117,13 @@ def test_change_with_resource_types(change_set, client, loader):
                                                            role_arn=None)
 
 
+def test_change_create_if_missing_without_parameter(change_set, client, loader):
+    client.get_caller_identity.return_value = {'Account': ACCOUNT_ID}
+    loader.return_value.template.return_value = TEMPLATE
+    cli.main(['change', '--stack', STACK])
+    client.describe_stacks.assert_not_called()
+
+
 def test_change_create_if_missing(change_set, client, loader):
     client.get_caller_identity.return_value = {'Account': ACCOUNT_ID}
     exception = ClientError(

tests/unit/test_stack_set.py

@@ -1,5 +1,7 @@
 import pytest
 import json
+from botocore.exceptions import ClientError
+
 from uuid import uuid4
 
 from formica import cli, stack_set
@@ -282,6 +284,31 @@ def test_update_stack_set_with_all_subaccounts(client, logger, loader, input, co
     )
 
 
+def test_update_with_create_missing(client, logger, loader, input, compare, wait):
+    client.update_stack_set.return_value = {'OperationId': '12345'}
+    client.list_accounts.return_value = ACCOUNTS
+    client.get_caller_identity.return_value = {'Account': '5678'}
+    client.describe_regions.return_value = EC2_REGIONS
+    exception = ClientError(
+        dict(Error={'Code': 'StackSetNotFoundException'}), "DescribeStackSet")
+    print(exception)
+    client.describe_stack_set.side_effect = exception
+    cli.main([
+        'stack-set',
+        'update',
+        '--stack-set', STACK,
+        '--all-subaccounts',
+        '--create-missing'
+    ])
+
+    client.create_stack_set.assert_called_with(
+        StackSetName=STACK,
+        TemplateBody=TEMPLATE
+    )
+
+    client.describe_stack_set.assert_called_with(StackSetName=STACK)
+
+
 def test_add_stack_set_instances(client, loader, wait, input):
     cli.main([
         'stack-set',