Add missing changes when creating a change set (#3039)

* Display changes when creating a change set

* add change set id and description when describing stack

* fix lint with flake8 and black

moto/cloudformation/models.py

@@ -219,7 +219,12 @@ class FakeStack(BaseModel):
         self.stack_id = stack_id
         self.name = name
         self.template = template
-        self._parse_template()
+        if template != {}:
+            self._parse_template()
+            self.description = self.template_dict.get("Description")
+        else:
+            self.template_dict = {}
+            self.description = None
         self.parameters = parameters
         self.region_name = region_name
         self.notification_arns = notification_arns if notification_arns else []
@@ -235,7 +240,6 @@ class FakeStack(BaseModel):
                 "CREATE_IN_PROGRESS", resource_status_reason="User Initiated"
             )
 
-        self.description = self.template_dict.get("Description")
         self.cross_stack_resources = cross_stack_resources or {}
         self.resource_map = self._create_resource_map()
         self.output_map = self._create_output_map()
@@ -331,7 +335,9 @@ class FakeStack(BaseModel):
         return self.output_map.exports
 
     def create_resources(self):
-        self.resource_map.create()
+        self.resource_map.create(self.template_dict)
+        # Set the description of the stack
+        self.description = self.template_dict.get("Description")
         self.status = "CREATE_COMPLETE"
 
     def update(self, template, role_arn=None, parameters=None, tags=None):
@@ -398,6 +404,8 @@ class FakeChangeSet(FakeStack):
         self.change_set_id = change_set_id
         self.change_set_name = change_set_name
         self.changes = self.diff(template=template, parameters=parameters)
+        if self.description is None:
+            self.description = self.template_dict.get("Description")
         self.creation_time = datetime.utcnow()
 
     def diff(self, template, parameters=None):
@@ -590,7 +598,7 @@ class CloudFormationBackend(BaseBackend):
                 raise ValidationError(stack_name)
         else:
             stack_id = generate_stack_id(stack_name, region_name)
-            stack_template = template
+            stack_template = {}
 
         change_set_id = generate_changeset_id(change_set_name, region_name)
         new_change_set = FakeChangeSet(
@@ -645,6 +653,9 @@ class CloudFormationBackend(BaseBackend):
         if stack is None:
             raise ValidationError(stack_name)
         if stack.events[-1].resource_status == "REVIEW_IN_PROGRESS":
+            stack._add_stack_event(
+                "CREATE_IN_PROGRESS", resource_status_reason="User Initiated"
+            )
             stack._add_stack_event("CREATE_COMPLETE")
         else:
             stack._add_stack_event("UPDATE_IN_PROGRESS")

moto/cloudformation/parsing.py

@@ -456,7 +456,7 @@ class ResourceMap(collections_abc.Mapping):
         cross_stack_resources,
     ):
         self._template = template
-        self._resource_json_map = template["Resources"]
+        self._resource_json_map = template["Resources"] if template != {} else {}
         self._region_name = region_name
         self.input_parameters = parameters
         self.tags = copy.deepcopy(tags)
@@ -592,10 +592,12 @@ class ResourceMap(collections_abc.Mapping):
         self.load_parameters()
         self.load_conditions()
 
-    def create(self):
+    def create(self, template):
         # Since this is a lazy map, to create every object we just need to
         # iterate through self.
         # Assumes that self.load() has been called before
+        self._template = template
+        self._resource_json_map = template["Resources"]
         self.tags.update(
             {
                 "aws:cloudformation:stack-name": self.get("AWS::StackName"),

moto/cloudformation/responses.py

@@ -662,6 +662,10 @@ DESCRIBE_STACKS_TEMPLATE = """<DescribeStacksResponse>
       <member>
         <StackName>{{ stack.name }}</StackName>
         <StackId>{{ stack.stack_id }}</StackId>
+        {% if stack.change_set_id %}
+        <ChangeSetId>{{ stack.change_set_id }}</ChangeSetId>
+        {% endif %}
+        <Description>{{ stack.description }}</Description>
         <CreationTime>{{ stack.creation_time_iso_8601 }}</CreationTime>
         <StackStatus>{{ stack.status }}</StackStatus>
         {% if stack.notification_arns %}

tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py

@@ -573,9 +573,9 @@ def test_boto3_create_stack_set_with_yaml():
 def test_create_stack_set_from_s3_url():
     s3 = boto3.client("s3")
     s3_conn = boto3.resource("s3", region_name="us-east-1")
-    bucket = s3_conn.create_bucket(Bucket="foobar")
+    s3_conn.create_bucket(Bucket="foobar")
 
-    key = s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
+    s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
     key_url = s3.generate_presigned_url(
         ClientMethod="get_object", Params={"Bucket": "foobar", "Key": "template-key"}
     )
@@ -716,9 +716,9 @@ def test_create_stack_with_role_arn():
 def test_create_stack_from_s3_url():
     s3 = boto3.client("s3")
     s3_conn = boto3.resource("s3", region_name="us-east-1")
-    bucket = s3_conn.create_bucket(Bucket="foobar")
+    s3_conn.create_bucket(Bucket="foobar")
 
-    key = s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
+    s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
     key_url = s3.generate_presigned_url(
         ClientMethod="get_object", Params={"Bucket": "foobar", "Key": "template-key"}
     )
@@ -800,9 +800,9 @@ def test_update_stack_from_s3_url():
 def test_create_change_set_from_s3_url():
     s3 = boto3.client("s3")
     s3_conn = boto3.resource("s3", region_name="us-east-1")
-    bucket = s3_conn.create_bucket(Bucket="foobar")
+    s3_conn.create_bucket(Bucket="foobar")
 
-    key = s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
+    s3_conn.Object("foobar", "template-key").put(Body=dummy_template_json)
     key_url = s3.generate_presigned_url(
         ClientMethod="get_object", Params={"Bucket": "foobar", "Key": "template-key"}
     )
@@ -844,6 +844,25 @@ def test_describe_change_set():
     assert (
         two_secs_ago < stack["CreationTime"] < datetime.now(tz=pytz.UTC)
     ), "Change set should have been created recently"
+    stack["Changes"].should.have.length_of(1)
+    stack["Changes"][0].should.equal(
+        dict(
+            {
+                "Type": "Resource",
+                "ResourceChange": {
+                    "Action": "Add",
+                    "LogicalResourceId": "EC2Instance1",
+                    "ResourceType": "AWS::EC2::Instance",
+                },
+            }
+        )
+    )
+
+    # Execute change set
+    cf_conn.execute_change_set(ChangeSetName="NewChangeSet")
+    # Verify that the changes have been applied
+    stack = cf_conn.describe_change_set(ChangeSetName="NewChangeSet")
+    stack["Changes"].should.have.length_of(1)
 
     cf_conn.create_change_set(
         StackName="NewStack",
@@ -887,7 +906,7 @@ def test_execute_change_set_w_arn():
 @mock_cloudformation
 def test_execute_change_set_w_name():
     cf_conn = boto3.client("cloudformation", region_name="us-east-1")
-    change_set = cf_conn.create_change_set(
+    cf_conn.create_change_set(
         StackName="NewStack",
         TemplateBody=dummy_template_json,
         ChangeSetName="NewChangeSet",
@@ -1221,9 +1240,7 @@ def test_delete_stack_with_export():
 @mock_cloudformation
 def test_export_names_must_be_unique():
     cf = boto3.resource("cloudformation", region_name="us-east-1")
-    first_stack = cf.create_stack(
-        StackName="test_stack", TemplateBody=dummy_output_template_json
-    )
+    cf.create_stack(StackName="test_stack", TemplateBody=dummy_output_template_json)
     with assert_raises(ClientError):
         cf.create_stack(StackName="test_stack", TemplateBody=dummy_output_template_json)
 
@@ -1237,9 +1254,7 @@ def test_stack_with_imports():
     output_stack = cf.create_stack(
         StackName="test_stack1", TemplateBody=dummy_output_template_json
     )
-    import_stack = cf.create_stack(
-        StackName="test_stack2", TemplateBody=dummy_import_template_json
-    )
+    cf.create_stack(StackName="test_stack2", TemplateBody=dummy_import_template_json)
 
     output_stack.outputs.should.have.length_of(1)
     output = output_stack.outputs[0]["OutputValue"]

tests/test_cloudformation/test_cloudformation_stack_integration.py

@@ -1,7 +1,6 @@
 from __future__ import unicode_literals
 import json
 
-import base64
 from decimal import Decimal
 
 import boto
@@ -28,7 +27,6 @@ from moto import (
     mock_dynamodb2,
     mock_ec2,
     mock_ec2_deprecated,
-    mock_elb,
     mock_elb_deprecated,
     mock_events,
     mock_iam_deprecated,
@@ -37,18 +35,14 @@ from moto import (
     mock_logs,
     mock_rds_deprecated,
     mock_rds2,
-    mock_rds2_deprecated,
-    mock_redshift,
     mock_redshift_deprecated,
     mock_route53_deprecated,
     mock_s3,
     mock_sns_deprecated,
-    mock_sqs,
     mock_sqs_deprecated,
     mock_elbv2,
 )
 from moto.core import ACCOUNT_ID
-from moto.dynamodb2.models import Table
 
 from tests.test_cloudformation.fixtures import (
     ec2_classic_eip,