Fix stackset describe/delete. Fix stackset update. (#3713)

* Fix stack set fetching and deleting.

* Also fix stackset update operation to accept previous values.

* Fix linting.

* Rename aliased test.

moto/cloudformation/models.py

@@ -467,6 +467,28 @@ class CloudFormationBackend(BaseBackend):
         self.exports = OrderedDict()
         self.change_sets = OrderedDict()
 
+    def _resolve_update_parameters(self, instance, incoming_params):
+        parameters = dict(
+            [
+                (parameter["parameter_key"], parameter["parameter_value"])
+                for parameter in incoming_params
+                if "parameter_value" in parameter
+            ]
+        )
+        previous = dict(
+            [
+                (
+                    parameter["parameter_key"],
+                    instance.parameters[parameter["parameter_key"]],
+                )
+                for parameter in incoming_params
+                if "use_previous_value" in parameter
+            ]
+        )
+        parameters.update(previous)
+
+        return parameters
+
     def create_stack_set(
         self,
         name,
@@ -494,6 +516,8 @@ class CloudFormationBackend(BaseBackend):
 
     def get_stack_set(self, name):
         stacksets = self.stacksets.keys()
+        if name in stacksets:
+            return self.stacksets[name]
         for stackset in stacksets:
             if self.stacksets[stackset].name == name:
                 return self.stacksets[stackset]
@@ -501,6 +525,8 @@ class CloudFormationBackend(BaseBackend):
 
     def delete_stack_set(self, name):
         stacksets = self.stacksets.keys()
+        if name in stacksets:
+            self.stacksets[name].delete()
         for stackset in stacksets:
             if self.stacksets[stackset].name == name:
                 self.stacksets[stackset].delete()
@@ -532,10 +558,13 @@ class CloudFormationBackend(BaseBackend):
         operation_id=None,
     ):
         stackset = self.get_stack_set(stackset_name)
+        resolved_parameters = self._resolve_update_parameters(
+            instance=stackset, incoming_params=parameters
+        )
         update = stackset.update(
             template=template,
             description=description,
-            parameters=parameters,
+            parameters=resolved_parameters,
             tags=tags,
             admin_role=admin_role,
             execution_role=execution_role,
@@ -711,7 +740,10 @@ class CloudFormationBackend(BaseBackend):
 
     def update_stack(self, name, template, role_arn=None, parameters=None, tags=None):
         stack = self.get_stack(name)
-        stack.update(template, role_arn, parameters=parameters, tags=tags)
+        resolved_parameters = self._resolve_update_parameters(
+            instance=stack, incoming_params=parameters
+        )
+        stack.update(template, role_arn, parameters=resolved_parameters, tags=tags)
         return stack
 
     def list_stack_resources(self, stack_name_or_id):

moto/cloudformation/responses.py

@@ -315,24 +315,6 @@ class CloudFormationResponse(BaseResponse):
             stack_body = self._get_stack_from_s3_url(template_url)
 
         incoming_params = self._get_list_prefix("Parameters.member")
-        parameters = dict(
-            [
-                (parameter["parameter_key"], parameter["parameter_value"])
-                for parameter in incoming_params
-                if "parameter_value" in parameter
-            ]
-        )
-        previous = dict(
-            [
-                (
-                    parameter["parameter_key"],
-                    stack.parameters[parameter["parameter_key"]],
-                )
-                for parameter in incoming_params
-                if "use_previous_value" in parameter
-            ]
-        )
-        parameters.update(previous)
         # boto3 is supposed to let you clear the tags by passing an empty value, but the request body doesn't
         # end up containing anything we can use to differentiate between passing an empty value versus not
         # passing anything. so until that changes, moto won't be able to clear tags, only update them.
@@ -357,7 +339,7 @@ class CloudFormationResponse(BaseResponse):
             name=stack_name,
             template=stack_body,
             role_arn=role_arn,
-            parameters=parameters,
+            parameters=incoming_params,
             tags=tags,
         )
         if self.request_json:
@@ -560,17 +542,12 @@ class CloudFormationResponse(BaseResponse):
             for item in self._get_list_prefix("Tags.member")
         )
         parameters_list = self._get_list_prefix("Parameters.member")
-        parameters = dict(
+
-            [
-                (parameter["parameter_key"], parameter["parameter_value"])
-                for parameter in parameters_list
-            ]
-        )
         operation = self.cloudformation_backend.update_stack_set(
             stackset_name=stackset_name,
             template=template_body,
             description=description,
-            parameters=parameters,
+            parameters=parameters_list,
             tags=tags,
             admin_role=admin_role,
             execution_role=execution_role,

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -558,6 +558,43 @@ def test_update_stack_set():
     )
 
 
+@mock_cloudformation
+def test_update_stack_set_with_previous_value():
+    cf_conn = boto3.client("cloudformation", region_name="us-east-1")
+    param = [
+        {"ParameterKey": "TagDescription", "ParameterValue": "StackSetValue"},
+        {"ParameterKey": "TagName", "ParameterValue": "StackSetValue2"},
+    ]
+    param_overrides = [
+        {"ParameterKey": "TagDescription", "ParameterValue": "OverrideValue"},
+        {"ParameterKey": "TagName", "UsePreviousValue": True},
+    ]
+    cf_conn.create_stack_set(
+        StackSetName="test_stack_set",
+        TemplateBody=dummy_template_yaml_with_ref,
+        Parameters=param,
+    )
+    cf_conn.update_stack_set(
+        StackSetName="test_stack_set",
+        TemplateBody=dummy_template_yaml_with_ref,
+        Parameters=param_overrides,
+    )
+    stackset = cf_conn.describe_stack_set(StackSetName="test_stack_set")
+
+    stackset["StackSet"]["Parameters"][0]["ParameterValue"].should.equal(
+        param_overrides[0]["ParameterValue"]
+    )
+    stackset["StackSet"]["Parameters"][1]["ParameterValue"].should.equal(
+        param[1]["ParameterValue"]
+    )
+    stackset["StackSet"]["Parameters"][0]["ParameterKey"].should.equal(
+        param_overrides[0]["ParameterKey"]
+    )
+    stackset["StackSet"]["Parameters"][1]["ParameterKey"].should.equal(
+        param_overrides[1]["ParameterKey"]
+    )
+
+
 @mock_cloudformation
 def test_boto3_list_stack_set_operations():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")
@@ -588,7 +625,7 @@ def test_boto3_bad_list_stack_resources():
 
 
 @mock_cloudformation
-def test_boto3_delete_stack_set():
+def test_boto3_delete_stack_set_by_name():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")
     cf_conn.create_stack_set(
         StackSetName="test_stack_set", TemplateBody=dummy_template_json
@@ -600,6 +637,20 @@ def test_boto3_delete_stack_set():
     ].should.equal("DELETED")
 
 
+@mock_cloudformation
+def test_boto3_delete_stack_set_by_id():
+    cf_conn = boto3.client("cloudformation", region_name="us-east-1")
+    response = cf_conn.create_stack_set(
+        StackSetName="test_stack_set", TemplateBody=dummy_template_json
+    )
+    stack_set_id = response["StackSetId"]
+    cf_conn.delete_stack_set(StackSetName=stack_set_id)
+
+    cf_conn.describe_stack_set(StackSetName="test_stack_set")["StackSet"][
+        "Status"
+    ].should.equal("DELETED")
+
+
 @mock_cloudformation
 def test_boto3_create_stack_set():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")
@@ -680,6 +731,19 @@ def test_boto3_describe_stack_set_params():
     ].should.equal(params)
 
 
+@mock_cloudformation
+def test_boto3_describe_stack_set_by_id():
+    cf_conn = boto3.client("cloudformation", region_name="us-east-1")
+    response = cf_conn.create_stack_set(
+        StackSetName="test_stack", TemplateBody=dummy_template_json,
+    )
+
+    stack_set_id = response["StackSetId"]
+    cf_conn.describe_stack_set(StackSetName=stack_set_id)["StackSet"][
+        "TemplateBody"
+    ].should.equal(dummy_template_json)
+
+
 @mock_cloudformation
 def test_boto3_create_stack():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")