From 2e9944165be7bc7380ea0131f5e26bf7f12498a1 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 18:23:56 +0100
Subject: [PATCH 01/18] WIP

---
 .../engine/v2/change_set_model_executor.py    |  5 +++
 .../engine/v2/change_set_model_validator.py   | 44 +++++++++++++++++++
 .../services/cloudformation/v2/provider.py    | 37 ++++++++++++++++
 .../v2/ported_from_v1/api/test_resources.py   | 11 +++++
 .../api/test_resources.snapshot.json          |  6 +++
 .../v2/ported_from_v1/api/test_stacks.py      | 12 ++++-
 .../api/test_stacks.snapshot.json             |  6 +++
 .../api/test_stacks.validation.json           |  9 ++++
 .../v2/ported_from_v1/resources/test_ec2.py   |  1 -
 9 files changed, 129 insertions(+), 2 deletions(-)
 create mode 100644 localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
 create mode 100644 tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
 create mode 100644 tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
index 8cab080b0d984..d5032ae9f33d8 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
@@ -18,6 +18,7 @@
     NodeDependsOn,
     NodeOutput,
     NodeParameter,
+    NodeParameters,
     NodeResource,
     is_nothing,
 )
@@ -69,6 +70,10 @@ def execute(self) -> ChangeSetModelExecutorResult:
             resources=self.resources, parameters=self.resolved_parameters, outputs=self.outputs
         )
 
+    def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntityDelta:
+        delta = super().visit_node_parameters(node_parameters)
+        return delta
+
     def visit_node_parameter(self, node_parameter: NodeParameter) -> PreprocEntityDelta:
         delta = super().visit_node_parameter(node_parameter)
 
diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
new file mode 100644
index 0000000000000..1b029be5870e6
--- /dev/null
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
@@ -0,0 +1,44 @@
+from typing import Final
+
+from localstack.services.cloudformation.engine.v2.change_set_model import (
+    NodeParameters,
+)
+from localstack.services.cloudformation.engine.v2.change_set_model_preproc import (
+    ChangeSetModelPreproc,
+    PreprocEntityDelta,
+)
+from localstack.services.cloudformation.engine.validations import ValidationError
+from localstack.services.cloudformation.v2.entities import ChangeSet
+
+
+class ChangeSetModelValidator(ChangeSetModelPreproc):
+    _before_parameters: Final[dict]
+    _after_parameters: Final[dict]
+
+    def __init__(
+        self,
+        change_set: ChangeSet,
+        before_parameters: dict,
+        after_parameters: dict,
+    ):
+        super().__init__(change_set)
+        self._before_parameters = before_parameters
+        self._after_parameters = after_parameters
+
+    def validate(self):
+        # validate parameters are all given
+        self.visit(self._change_set.update_model.node_template.parameters)
+
+    def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntityDelta:
+        delta = super().visit_node_parameters(node_parameters)
+        # assert before
+        if self._before_parameters:
+            missing_values = [key for key in delta.before if delta.before[key] is None]
+            if missing_values:
+                raise ValidationError()
+        if self._after_parameters:
+            missing_values = [key for key in delta.after if delta.before[key] is None]
+            if missing_values:
+                raise ValidationError()
+
+        return delta
diff --git a/localstack-core/localstack/services/cloudformation/v2/provider.py b/localstack-core/localstack/services/cloudformation/v2/provider.py
index 26f8974f557aa..dffa660f52a6b 100644
--- a/localstack-core/localstack/services/cloudformation/v2/provider.py
+++ b/localstack-core/localstack/services/cloudformation/v2/provider.py
@@ -21,6 +21,7 @@
     DeletionMode,
     DescribeChangeSetOutput,
     DescribeStackEventsOutput,
+    DescribeStackResourceOutput,
     DescribeStackResourcesOutput,
     DescribeStacksOutput,
     DisableRollback,
@@ -67,6 +68,9 @@
 from localstack.services.cloudformation.engine.v2.change_set_model_transform import (
     ChangeSetModelTransform,
 )
+from localstack.services.cloudformation.engine.v2.change_set_model_validator import (
+    ChangeSetModelValidator,
+)
 from localstack.services.cloudformation.engine.validations import ValidationError
 from localstack.services.cloudformation.provider import (
     ARN_CHANGESET_REGEX,
@@ -190,6 +194,15 @@ def _setup_change_set_model(
         # the transformations.
         update_model.before_runtime_cache.update(raw_update_model.before_runtime_cache)
         update_model.after_runtime_cache.update(raw_update_model.after_runtime_cache)
+
+        # perform validations
+        validator = ChangeSetModelValidator(
+            change_set=change_set,
+            before_parameters=before_parameters,
+            after_parameters=after_parameters,
+        )
+        validator.validate()
+
         change_set.set_update_model(update_model)
         change_set.stack.processed_template = transformed_after_template
 
@@ -643,6 +656,30 @@ def list_stacks(
         stacks = [select_attributes(stack, attrs) for stack in stacks]
         return ListStacksOutput(StackSummaries=stacks)
 
+    @handler("DescribeStackResource")
+    def describe_stack_resource(
+        self,
+        context: RequestContext,
+        stack_name: StackName,
+        logical_resource_id: LogicalResourceId,
+        **kwargs,
+    ) -> DescribeStackResourceOutput:
+        state = get_cloudformation_store(context.account_id, context.region)
+        stack = find_stack_v2(state, stack_name)
+        if not stack:
+            raise StackNotFoundError(stack_name)
+
+        try:
+            resource = stack.resolved_resources[logical_resource_id]
+        except KeyError as e:
+            if "Unable to find details" in str(e):
+                raise ValidationError(
+                    f"Resource {logical_resource_id} does not exist for stack {stack_name}"
+                )
+            raise
+
+        return DescribeStackResourceOutput(StackResourceDetail=details)
+
     @handler("DescribeStackResources")
     def describe_stack_resources(
         self,
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
new file mode 100644
index 0000000000000..d0cc4f1d17579
--- /dev/null
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
@@ -0,0 +1,11 @@
+import os
+
+from localstack.testing.pytest import markers
+
+
+@markers.aws.validated
+def test_describe_non_existent_resource(aws_client, deploy_cfn_template, snapshot):
+    template_path = os.path.join(
+        os.path.dirname(__file__), "../../../../../templates/ssm_parameter_defaultname.yaml"
+    )
+    stack = deploy_cfn_template(template_path=template_path)
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
new file mode 100644
index 0000000000000..1985c68b286cc
--- /dev/null
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
@@ -0,0 +1,6 @@
+{
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_describe_non_existent_resource": {
+    "recorded-date": "25-07-2025, 15:24:21",
+    "recorded-content": {}
+  }
+}
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
index 05fad77292e8c..20ed8e5a420ac 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
@@ -6,7 +6,7 @@
 import botocore.exceptions
 import pytest
 import yaml
-from botocore.exceptions import WaiterError
+from botocore.exceptions import ClientError, WaiterError
 from localstack_snapshot.snapshots.transformer import SortingTransformer
 
 from localstack.aws.api.cloudformation import Capability
@@ -1061,3 +1061,13 @@ def test_stack_resource_not_found(deploy_cfn_template, aws_client, snapshot):
 
     snapshot.add_transformer(snapshot.transform.regex(stack.stack_name, "<stack-name>"))
     snapshot.match("Error", ex.value.response)
+
+
+@markers.aws.validated
+def test_no_parameters_given(aws_client, deploy_cfn_template, snapshot):
+    template_path = os.path.join(
+        os.path.dirname(__file__), "../../../../../templates/ssm_parameter_defaultname.yaml"
+    )
+    with pytest.raises(ClientError) as exc_info:
+        deploy_cfn_template(template_path=template_path, parameters={"Input": "Foo"})
+    snapshot.match("deploy-error", exc_info.value)
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.snapshot.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.snapshot.json
index 979af0c8a9573..63ac9b9c14b57 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.snapshot.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.snapshot.json
@@ -2286,5 +2286,11 @@
         }
       }
     }
+  },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py::test_no_parameters_given": {
+    "recorded-date": "25-07-2025, 15:34:21",
+    "recorded-content": {
+      "deploy-error": "An error occurred (ValidationError) when calling the CreateChangeSet operation: Parameters: [Input] must have values"
+    }
   }
 }
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.validation.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.validation.json
index 005063a3a34ee..fc5d362607d93 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.validation.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.validation.json
@@ -62,6 +62,15 @@
   "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py::test_no_echo_parameter": {
     "last_validated_date": "2024-12-19T11:35:15+00:00"
   },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py::test_no_parameters_given": {
+    "last_validated_date": "2025-07-25T15:34:21+00:00",
+    "durations_in_seconds": {
+      "setup": 1.24,
+      "call": 0.3,
+      "teardown": 0.0,
+      "total": 1.54
+    }
+  },
   "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py::test_stack_deploy_order2": {
     "last_validated_date": "2024-05-21T09:48:14+00:00"
   },
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_ec2.py b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_ec2.py
index a31bf40d39240..8cecb1c3627a0 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_ec2.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_ec2.py
@@ -128,7 +128,6 @@ def test_cfn_with_multiple_route_table_associations(deploy_cfn_template, aws_cli
     snapshot.add_transformer(snapshot.transform.key_value("VpcId"))
 
 
-@pytest.mark.skip(reason="CFNV2:Describe")
 @markers.aws.validated
 @markers.snapshot.skip_snapshot_verify(paths=["$..DriftInformation", "$..Metadata"])
 def test_internet_gateway_ref_and_attr(deploy_cfn_template, snapshot, aws_client):

From a6717dc9990d6288e0cc6db90826d4310f6ecc1a Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 22:34:19 +0100
Subject: [PATCH 02/18] Type resolved resources

---
 .../cloudformation/engine/v2/change_set_model_executor.py   | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
index d5032ae9f33d8..9ed2bedaef1ac 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
@@ -37,7 +37,7 @@
     ResourceProviderExecutor,
     ResourceProviderPayload,
 )
-from localstack.services.cloudformation.v2.entities import ChangeSet
+from localstack.services.cloudformation.v2.entities import ChangeSet, ResolvedResource
 
 LOG = logging.getLogger(__name__)
 
@@ -46,14 +46,14 @@
 
 @dataclass
 class ChangeSetModelExecutorResult:
-    resources: dict
+    resources: dict[str, ResolvedResource]
     parameters: dict
     outputs: dict
 
 
 class ChangeSetModelExecutor(ChangeSetModelPreproc):
     # TODO: add typing for resolved resources and parameters.
-    resources: Final[dict]
+    resources: Final[dict[str, ResolvedResource]]
     outputs: Final[dict]
     resolved_parameters: Final[dict]
 

From 96f13be1995b42b69cc6ac11ff9322df04cb5f27 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 22:55:54 +0100
Subject: [PATCH 03/18] Restructure the way the ResolvedResource works

---
 .../engine/v2/change_set_model_executor.py    | 24 ++++++++++++-------
 .../services/cloudformation/v2/entities.py    |  4 ++++
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
index 9ed2bedaef1ac..a1804cce2ce62 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
@@ -2,6 +2,7 @@
 import logging
 import uuid
 from dataclasses import dataclass
+from datetime import datetime, timezone
 from typing import Final, Optional
 
 from localstack import config
@@ -414,7 +415,6 @@ def _execute_resource_action(
                 message=f"Resource type {resource_type} not supported",
             )
 
-        self.resources.setdefault(logical_resource_id, {"Properties": {}})
         match event.status:
             case OperationStatus.SUCCESS:
                 # merge the resources state with the external state
@@ -427,18 +427,24 @@ def _execute_resource_action(
                 # TODO: avoid the use of setdefault (debuggability/readability)
                 # TODO: review the use of merge
 
-                self.resources[logical_resource_id]["Properties"].update(event.resource_model)
-                self.resources[logical_resource_id].update(extra_resource_properties)
-                # XXX for legacy delete_stack compatibility
-                self.resources[logical_resource_id]["LogicalResourceId"] = logical_resource_id
-                self.resources[logical_resource_id]["Type"] = resource_type
-
+                status_from_action = EventOperationFromAction[action.value]
                 physical_resource_id = (
-                    self._get_physical_id(logical_resource_id)
+                    extra_resource_properties["PhysicalResourceId"]
                     if resource_provider
                     else MOCKED_REFERENCE
                 )
-                self.resources[logical_resource_id]["PhysicalResourceId"] = physical_resource_id
+                resolved_resource = ResolvedResource(
+                    Properties=event.resource_model,
+                    LogicalResourceId=logical_resource_id,
+                    Type=resource_type,
+                    LastUpdatedTimestamp=datetime.now(timezone.utc),
+                    ResourceStatus=ResourceStatus(f"{status_from_action}_COMPLETE"),
+                    PhysicalResourceId=physical_resource_id,
+                )
+                # TODO: do we actually need this line?
+                resolved_resource.update(extra_resource_properties)
+
+                self.resources[logical_resource_id] = resolved_resource
 
             case OperationStatus.FAILED:
                 reason = event.message
diff --git a/localstack-core/localstack/services/cloudformation/v2/entities.py b/localstack-core/localstack/services/cloudformation/v2/entities.py
index 0add53bfb5e84..a568692ea5e53 100644
--- a/localstack-core/localstack/services/cloudformation/v2/entities.py
+++ b/localstack-core/localstack/services/cloudformation/v2/entities.py
@@ -34,8 +34,12 @@
 
 
 class ResolvedResource(TypedDict):
+    LogicalResourceId: str
     Type: str
     Properties: dict
+    ResourceStatus: ResourceStatus
+    PhysicalResourceId: str | None
+    LastUpdatedTimestamp: datetime | None
 
 
 class Stack:

From 892e1b81a482d3288dd2bb1b4b958e38e4bba2b6 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 22:57:10 +0100
Subject: [PATCH 04/18] Handle validation of parameter values

---
 .../engine/v2/change_set_model_validator.py   | 45 ++++++++-----------
 .../services/cloudformation/v2/provider.py    |  2 -
 2 files changed, 18 insertions(+), 29 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
index 1b029be5870e6..cc67959aee4bb 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
@@ -1,44 +1,35 @@
-from typing import Final
-
 from localstack.services.cloudformation.engine.v2.change_set_model import (
     NodeParameters,
+    NodeTemplate,
+    is_nothing,
 )
 from localstack.services.cloudformation.engine.v2.change_set_model_preproc import (
     ChangeSetModelPreproc,
     PreprocEntityDelta,
 )
 from localstack.services.cloudformation.engine.validations import ValidationError
-from localstack.services.cloudformation.v2.entities import ChangeSet
 
 
 class ChangeSetModelValidator(ChangeSetModelPreproc):
-    _before_parameters: Final[dict]
-    _after_parameters: Final[dict]
-
-    def __init__(
-        self,
-        change_set: ChangeSet,
-        before_parameters: dict,
-        after_parameters: dict,
-    ):
-        super().__init__(change_set)
-        self._before_parameters = before_parameters
-        self._after_parameters = after_parameters
-
     def validate(self):
         # validate parameters are all given
         self.visit(self._change_set.update_model.node_template.parameters)
 
+    def visit_node_template(self, node_template: NodeTemplate):
+        self.visit_node_parameters(node_template.parameters)
+
     def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntityDelta:
-        delta = super().visit_node_parameters(node_parameters)
-        # assert before
-        if self._before_parameters:
-            missing_values = [key for key in delta.before if delta.before[key] is None]
-            if missing_values:
-                raise ValidationError()
-        if self._after_parameters:
-            missing_values = [key for key in delta.after if delta.before[key] is None]
-            if missing_values:
-                raise ValidationError()
+        # check that all parameters have values
+        invalid_parameters = []
+        for node_parameter in node_parameters.parameters:
+            self.visit(node_parameter)
+            if is_nothing(node_parameter.default_value.value) and is_nothing(
+                node_parameter.dynamic_value.value
+            ):
+                invalid_parameters.append(node_parameter.name)
+
+        if invalid_parameters:
+            raise ValidationError(f"Parameters: [{','.join(invalid_parameters)}] must have values")
 
-        return delta
+        # continue visiting
+        return super().visit_node_parameters(node_parameters)
diff --git a/localstack-core/localstack/services/cloudformation/v2/provider.py b/localstack-core/localstack/services/cloudformation/v2/provider.py
index dffa660f52a6b..eaccb9f512627 100644
--- a/localstack-core/localstack/services/cloudformation/v2/provider.py
+++ b/localstack-core/localstack/services/cloudformation/v2/provider.py
@@ -198,8 +198,6 @@ def _setup_change_set_model(
         # perform validations
         validator = ChangeSetModelValidator(
             change_set=change_set,
-            before_parameters=before_parameters,
-            after_parameters=after_parameters,
         )
         validator.validate()
 

From d3a1aa90481afa0113bad2056a7a22edb30ca394 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 22:57:23 +0100
Subject: [PATCH 05/18] Implement describe-stack-resource

---
 .../services/cloudformation/v2/provider.py    | 22 +++++++++++++------
 .../v2/ported_from_v1/api/test_stacks.py      |  3 +--
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/v2/provider.py b/localstack-core/localstack/services/cloudformation/v2/provider.py
index eaccb9f512627..0c1a13971cb9a 100644
--- a/localstack-core/localstack/services/cloudformation/v2/provider.py
+++ b/localstack-core/localstack/services/cloudformation/v2/provider.py
@@ -45,6 +45,7 @@
     RollbackConfiguration,
     StackName,
     StackNameOrId,
+    StackResourceDetail,
     StackStatus,
     StackStatusFilter,
     TemplateStage,
@@ -669,14 +670,21 @@ def describe_stack_resource(
 
         try:
             resource = stack.resolved_resources[logical_resource_id]
-        except KeyError as e:
-            if "Unable to find details" in str(e):
-                raise ValidationError(
-                    f"Resource {logical_resource_id} does not exist for stack {stack_name}"
-                )
-            raise
+        except KeyError:
+            raise ValidationError(
+                f"Resource {logical_resource_id} does not exist for stack {stack_name}"
+            )
 
-        return DescribeStackResourceOutput(StackResourceDetail=details)
+        resource_detail = StackResourceDetail(
+            StackName=stack.stack_name,
+            StackId=stack.stack_id,
+            LogicalResourceId=logical_resource_id,
+            PhysicalResourceId=resource["PhysicalResourceId"],
+            ResourceType=resource["Type"],
+            LastUpdatedTimestamp=resource["LastUpdatedTimestamp"],
+            ResourceStatus=resource["ResourceStatus"],
+        )
+        return DescribeStackResourceOutput(StackResourceDetail=resource_detail)
 
     @handler("DescribeStackResources")
     def describe_stack_resources(
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
index 20ed8e5a420ac..b65f0fae31ebe 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
@@ -1044,7 +1044,6 @@ def test_no_echo_parameter(snapshot, aws_client, deploy_cfn_template):
     snapshot.match("describe_updated_stacks_no_echo_false", describe_stacks)
 
 
-@pytest.mark.skip(reason="CFNV2:Validation")
 @markers.aws.validated
 def test_stack_resource_not_found(deploy_cfn_template, aws_client, snapshot):
     stack = deploy_cfn_template(
@@ -1069,5 +1068,5 @@ def test_no_parameters_given(aws_client, deploy_cfn_template, snapshot):
         os.path.dirname(__file__), "../../../../../templates/ssm_parameter_defaultname.yaml"
     )
     with pytest.raises(ClientError) as exc_info:
-        deploy_cfn_template(template_path=template_path, parameters={"Input": "Foo"})
+        deploy_cfn_template(template_path=template_path)
     snapshot.match("deploy-error", exc_info.value)

From 18a24b6a4827a22b4c7fa3c1c6a1e51030e35ef0 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 23:02:09 +0100
Subject: [PATCH 06/18] Add test for describing non-existent resource

---
 .../v2/ported_from_v1/api/test_resources.py         | 13 ++++++++++++-
 .../ported_from_v1/api/test_resources.snapshot.json |  6 ++++--
 .../api/test_resources.validation.json              | 11 +++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json

diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
index d0cc4f1d17579..c8e7193df356d 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
@@ -1,5 +1,8 @@
 import os
 
+import pytest
+from botocore.exceptions import ClientError
+
 from localstack.testing.pytest import markers
 
 
@@ -8,4 +11,12 @@ def test_describe_non_existent_resource(aws_client, deploy_cfn_template, snapsho
     template_path = os.path.join(
         os.path.dirname(__file__), "../../../../../templates/ssm_parameter_defaultname.yaml"
     )
-    stack = deploy_cfn_template(template_path=template_path)
+    stack = deploy_cfn_template(template_path=template_path, parameters={"Input": "myvalue"})
+    snapshot.add_transformer(snapshot.transform.regex(stack.stack_id, "<stack-id>"))
+
+    with pytest.raises(ClientError) as err:
+        aws_client.cloudformation.describe_stack_resource(
+            StackName=stack.stack_id, LogicalResourceId="not-a-valid-resource"
+        )
+
+    snapshot.match("error", err.value)
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
index 1985c68b286cc..198fbfd09af80 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
@@ -1,6 +1,8 @@
 {
   "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_describe_non_existent_resource": {
-    "recorded-date": "25-07-2025, 15:24:21",
-    "recorded-content": {}
+    "recorded-date": "25-07-2025, 22:01:35",
+    "recorded-content": {
+      "error": "An error occurred (ValidationError) when calling the DescribeStackResource operation: Resource not-a-valid-resource does not exist for stack <stack-id>"
+    }
   }
 }
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
new file mode 100644
index 0000000000000..8d1da2d0d6d98
--- /dev/null
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
@@ -0,0 +1,11 @@
+{
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_describe_non_existent_resource": {
+    "last_validated_date": "2025-07-25T22:01:40+00:00",
+    "durations_in_seconds": {
+      "setup": 1.11,
+      "call": 10.33,
+      "teardown": 4.37,
+      "total": 15.81
+    }
+  }
+}

From d1907cd42ca13a6a70d4896ca02ab14a3e41158a Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 23:05:30 +0100
Subject: [PATCH 07/18] Handle error cases for describing stack resources

---
 .../services/cloudformation/v2/provider.py        | 15 ++++++++++-----
 .../v2/ported_from_v1/api/test_resources.py       | 10 ++++++++++
 .../api/test_resources.snapshot.json              |  6 ++++++
 .../api/test_resources.validation.json            |  9 +++++++++
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/v2/provider.py b/localstack-core/localstack/services/cloudformation/v2/provider.py
index 0c1a13971cb9a..1c21ede098fc1 100644
--- a/localstack-core/localstack/services/cloudformation/v2/provider.py
+++ b/localstack-core/localstack/services/cloudformation/v2/provider.py
@@ -98,11 +98,14 @@ def is_changeset_arn(change_set_name_or_id: str) -> bool:
 
 
 class StackNotFoundError(ValidationError):
-    def __init__(self, stack_name_or_id: str):
-        if is_stack_arn(stack_name_or_id):
-            super().__init__(f"Stack with id {stack_name_or_id} does not exist")
+    def __init__(self, stack_name_or_id: str, message_override: str | None = None):
+        if message_override:
+            super().__init__(message_override)
         else:
-            super().__init__(f"Stack [{stack_name_or_id}] does not exist")
+            if is_stack_arn(stack_name_or_id):
+                super().__init__(f"Stack with id {stack_name_or_id} does not exist")
+            else:
+                super().__init__(f"Stack [{stack_name_or_id}] does not exist")
 
 
 def find_stack_v2(state: CloudFormationStore, stack_name: str | None) -> Stack | None:
@@ -666,7 +669,9 @@ def describe_stack_resource(
         state = get_cloudformation_store(context.account_id, context.region)
         stack = find_stack_v2(state, stack_name)
         if not stack:
-            raise StackNotFoundError(stack_name)
+            raise StackNotFoundError(
+                stack_name, message_override=f"Stack '{stack_name}' does not exist"
+            )
 
         try:
             resource = stack.resolved_resources[logical_resource_id]
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
index c8e7193df356d..e7d7bf2644667 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
@@ -6,6 +6,16 @@
 from localstack.testing.pytest import markers
 
 
+@markers.aws.validated
+def test_describe_non_existent_stack(aws_client, deploy_cfn_template, snapshot):
+    with pytest.raises(ClientError) as err:
+        aws_client.cloudformation.describe_stack_resource(
+            StackName="not-a-valid-stack", LogicalResourceId="not-a-valid-resource"
+        )
+
+    snapshot.match("error", err.value)
+
+
 @markers.aws.validated
 def test_describe_non_existent_resource(aws_client, deploy_cfn_template, snapshot):
     template_path = os.path.join(
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
index 198fbfd09af80..2c7d2322a05bf 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
@@ -4,5 +4,11 @@
     "recorded-content": {
       "error": "An error occurred (ValidationError) when calling the DescribeStackResource operation: Resource not-a-valid-resource does not exist for stack <stack-id>"
     }
+  },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_describe_non_existent_stack": {
+    "recorded-date": "25-07-2025, 22:02:38",
+    "recorded-content": {
+      "error": "An error occurred (ValidationError) when calling the DescribeStackResource operation: Stack 'not-a-valid-stack' does not exist"
+    }
   }
 }
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
index 8d1da2d0d6d98..5cc65ecfc0159 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
@@ -7,5 +7,14 @@
       "teardown": 4.37,
       "total": 15.81
     }
+  },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_describe_non_existent_stack": {
+    "last_validated_date": "2025-07-25T22:02:38+00:00",
+    "durations_in_seconds": {
+      "setup": 1.04,
+      "call": 0.2,
+      "teardown": 0.0,
+      "total": 1.24
+    }
   }
 }

From beff6eecfffbad368ee0d9caab842ea16c04e44d Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 23:12:24 +0100
Subject: [PATCH 08/18] Unskip tests

---
 .../cloudformation/v2/ported_from_v1/api/test_stacks.py       | 1 -
 .../cloudformation/v2/ported_from_v1/resources/test_cdk.py    | 1 -
 .../cloudformation/v2/ported_from_v1/resources/test_events.py | 1 -
 .../cloudformation/v2/ported_from_v1/resources/test_lambda.py | 4 ----
 4 files changed, 7 deletions(-)

diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
index b65f0fae31ebe..3c0ad16202fc6 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
@@ -910,7 +910,6 @@ def test_stack_deploy_order(deploy_cfn_template, aws_client, snapshot, deploy_or
     snapshot.match("events", filtered_events)
 
 
-@pytest.mark.skip(reason="CFNV2:DescribeStack")
 @markers.snapshot.skip_snapshot_verify(
     paths=[
         # TODO: this property is present in the response from LocalStack when
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_cdk.py b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_cdk.py
index 538013909d4ce..0140153b6dc89 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_cdk.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_cdk.py
@@ -99,7 +99,6 @@ def clean_resources():
 
 
 class TestCdkSampleApp:
-    @pytest.mark.skip(reason="CFNV2:Describe")
     @markers.snapshot.skip_snapshot_verify(
         paths=[
             "$..Attributes.Policy.Statement..Condition",
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_events.py b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_events.py
index 17f1efcac75f8..571c6cdfb3f74 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_events.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_events.py
@@ -47,7 +47,6 @@ def _assert(expected_len):
     _assert(0)
 
 
-@pytest.mark.skip(reason="CFNV2:Describe")
 @markers.aws.validated
 def test_eventbus_policies(deploy_cfn_template, aws_client):
     event_bus_name = f"event-bus-{short_uid()}"
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_lambda.py b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_lambda.py
index ce5570b67476e..2f5e2cd70ffd2 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_lambda.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/resources/test_lambda.py
@@ -157,7 +157,6 @@ def test_update_lambda_function_name(s3_create_bucket, deploy_cfn_template, aws_
     aws_client.lambda_.get_function(FunctionName=function_name_2)
 
 
-@pytest.mark.skip(reason="CFNV2:Describe")
 @markers.snapshot.skip_snapshot_verify(
     paths=[
         "$..Metadata",
@@ -728,7 +727,6 @@ def wait_logs():
 
         assert wait_until(wait_logs)
 
-    @pytest.mark.skip(reason="CFNV2:DescribeStackResources")
     @markers.snapshot.skip_snapshot_verify(
         paths=[
             # Lambda
@@ -887,7 +885,6 @@ def _send_events():
         sleep = 10 if os.getenv("TEST_TARGET") == "AWS_CLOUD" else 1
         assert wait_until(_send_events, wait=sleep, max_retries=50)
 
-    @pytest.mark.skip(reason="CFNV2:Describe")
     @markers.snapshot.skip_snapshot_verify(
         paths=[
             # Lambda
@@ -1025,7 +1022,6 @@ def wait_logs():
         with pytest.raises(aws_client.lambda_.exceptions.ResourceNotFoundException):
             aws_client.lambda_.get_event_source_mapping(UUID=esm_id)
 
-    @pytest.mark.skip(reason="CFNV2:Describe")
     @markers.snapshot.skip_snapshot_verify(
         paths=[
             "$..Role.Description",

From ce1a1087c0b51a24362cf958a6b41aae553d5dae Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 23:17:42 +0100
Subject: [PATCH 09/18] Remove unused method override

---
 .../cloudformation/engine/v2/change_set_model_executor.py    | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
index a1804cce2ce62..77105d6273d01 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_executor.py
@@ -19,7 +19,6 @@
     NodeDependsOn,
     NodeOutput,
     NodeParameter,
-    NodeParameters,
     NodeResource,
     is_nothing,
 )
@@ -71,10 +70,6 @@ def execute(self) -> ChangeSetModelExecutorResult:
             resources=self.resources, parameters=self.resolved_parameters, outputs=self.outputs
         )
 
-    def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntityDelta:
-        delta = super().visit_node_parameters(node_parameters)
-        return delta
-
     def visit_node_parameter(self, node_parameter: NodeParameter) -> PreprocEntityDelta:
         delta = super().visit_node_parameter(node_parameter)
 

From f3374927b4bac85d9808fb5e930ff5b0a8599ec8 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Fri, 25 Jul 2025 23:26:27 +0100
Subject: [PATCH 10/18] Add validation of logical resource ids

---
 .../engine/v2/change_set_model_validator.py   | 18 ++++++++++++++---
 .../v2/ported_from_v1/api/test_resources.py   | 20 +++++++++++++++++++
 .../api/test_resources.snapshot.json          |  6 ++++++
 .../api/test_resources.validation.json        |  9 +++++++++
 4 files changed, 50 insertions(+), 3 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
index cc67959aee4bb..e4b3f00f6059c 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
@@ -1,5 +1,8 @@
+import re
+
 from localstack.services.cloudformation.engine.v2.change_set_model import (
     NodeParameters,
+    NodeResource,
     NodeTemplate,
     is_nothing,
 )
@@ -9,14 +12,16 @@
 )
 from localstack.services.cloudformation.engine.validations import ValidationError
 
+VALID_LOGICAL_RESOURCE_ID_RE = re.compile(r"^[A-Za-z0-9]+$")
+
 
 class ChangeSetModelValidator(ChangeSetModelPreproc):
     def validate(self):
-        # validate parameters are all given
-        self.visit(self._change_set.update_model.node_template.parameters)
+        self.visit(self._change_set.update_model.node_template)
 
     def visit_node_template(self, node_template: NodeTemplate):
-        self.visit_node_parameters(node_template.parameters)
+        self.visit(node_template.parameters)
+        self.visit(node_template.resources)
 
     def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntityDelta:
         # check that all parameters have values
@@ -33,3 +38,10 @@ def visit_node_parameters(self, node_parameters: NodeParameters) -> PreprocEntit
 
         # continue visiting
         return super().visit_node_parameters(node_parameters)
+
+    def visit_node_resource(self, node_resource: NodeResource) -> PreprocEntityDelta:
+        if not VALID_LOGICAL_RESOURCE_ID_RE.match(node_resource.name):
+            raise ValidationError(
+                f"Template format error: Resource name {node_resource.name} is non alphanumeric."
+            )
+        return super().visit_node_resource(node_resource)
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
index e7d7bf2644667..ee6f8e960568a 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py
@@ -1,3 +1,4 @@
+import json
 import os
 
 import pytest
@@ -30,3 +31,22 @@ def test_describe_non_existent_resource(aws_client, deploy_cfn_template, snapsho
         )
 
     snapshot.match("error", err.value)
+
+
+@markers.aws.validated
+def test_invalid_logical_resource_id(deploy_cfn_template, snapshot):
+    template = {
+        "Resources": {
+            "my-bad-resource-id": {
+                "Type": "AWS::SSM::Parameter",
+                "Properties": {
+                    "Type": "String",
+                    "Value": "Foo",
+                },
+            }
+        }
+    }
+    with pytest.raises(ClientError) as err:
+        deploy_cfn_template(template=json.dumps(template))
+
+    snapshot.match("error", err.value)
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
index 2c7d2322a05bf..6c6ec67947625 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.snapshot.json
@@ -10,5 +10,11 @@
     "recorded-content": {
       "error": "An error occurred (ValidationError) when calling the DescribeStackResource operation: Stack 'not-a-valid-stack' does not exist"
     }
+  },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_invalid_logical_resource_id": {
+    "recorded-date": "25-07-2025, 22:21:31",
+    "recorded-content": {
+      "error": "An error occurred (ValidationError) when calling the CreateChangeSet operation: Template format error: Resource name my-bad-resource-id is non alphanumeric."
+    }
   }
 }
diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
index 5cc65ecfc0159..4bd2c1ca3dd99 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.validation.json
@@ -16,5 +16,14 @@
       "teardown": 0.0,
       "total": 1.24
     }
+  },
+  "tests/aws/services/cloudformation/v2/ported_from_v1/api/test_resources.py::test_invalid_logical_resource_id": {
+    "last_validated_date": "2025-07-25T22:21:31+00:00",
+    "durations_in_seconds": {
+      "setup": 1.31,
+      "call": 0.35,
+      "teardown": 0.0,
+      "total": 1.66
+    }
   }
 }

From cea35667aef8c628f7d150af9fd47c021c757a21 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sat, 26 Jul 2025 05:32:47 +0100
Subject: [PATCH 11/18] Increased test timeout

---
 .github/workflows/aws-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/aws-tests.yml b/.github/workflows/aws-tests.yml
index 6bb60c7be4a31..ea97e812fc828 100644
--- a/.github/workflows/aws-tests.yml
+++ b/.github/workflows/aws-tests.yml
@@ -822,7 +822,7 @@ jobs:
           path: dist/testselection/
 
       - name: Run CloudFormation Engine v2 Tests
-        timeout-minutes: 30
+        timeout-minutes: 60
         env:
           # add the GitHub API token to avoid rate limit issues
           GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}

From be599f7b3b7566f8730c18642f482ee60a4c87ad Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sat, 26 Jul 2025 22:23:19 +0100
Subject: [PATCH 12/18] Validator inherits directly from visitor

We don't need preprocessing in this implmenentation
---
 .../engine/v2/change_set_model_validator.py            | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
index e4b3f00f6059c..8176733b44667 100644
--- a/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
+++ b/localstack-core/localstack/services/cloudformation/engine/v2/change_set_model_validator.py
@@ -7,15 +7,21 @@
     is_nothing,
 )
 from localstack.services.cloudformation.engine.v2.change_set_model_preproc import (
-    ChangeSetModelPreproc,
     PreprocEntityDelta,
 )
+from localstack.services.cloudformation.engine.v2.change_set_model_visitor import (
+    ChangeSetModelVisitor,
+)
 from localstack.services.cloudformation.engine.validations import ValidationError
+from localstack.services.cloudformation.v2.entities import ChangeSet
 
 VALID_LOGICAL_RESOURCE_ID_RE = re.compile(r"^[A-Za-z0-9]+$")
 
 
-class ChangeSetModelValidator(ChangeSetModelPreproc):
+class ChangeSetModelValidator(ChangeSetModelVisitor):
+    def __init__(self, change_set: ChangeSet):
+        self._change_set = change_set
+
     def validate(self):
         self.visit(self._change_set.update_model.node_template)
 

From 756b0a00cea3797c3114fa1455ebc1c257869d24 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sat, 26 Jul 2025 22:24:40 +0100
Subject: [PATCH 13/18] Revert "Increased test timeout"

This reverts commit cea35667aef8c628f7d150af9fd47c021c757a21.
---
 .github/workflows/aws-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/aws-tests.yml b/.github/workflows/aws-tests.yml
index ea97e812fc828..6bb60c7be4a31 100644
--- a/.github/workflows/aws-tests.yml
+++ b/.github/workflows/aws-tests.yml
@@ -822,7 +822,7 @@ jobs:
           path: dist/testselection/
 
       - name: Run CloudFormation Engine v2 Tests
-        timeout-minutes: 60
+        timeout-minutes: 30
         env:
           # add the GitHub API token to avoid rate limit issues
           GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}

From 948c8d58358691cdb2a399d26daf1a0c0694911b Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sun, 27 Jul 2025 20:03:14 +0100
Subject: [PATCH 14/18] Ignore cloudformation v2 tests for community tests
 against pro

---
 .github/workflows/tests-pro-integration.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/tests-pro-integration.yml b/.github/workflows/tests-pro-integration.yml
index 92e8eb09e8d57..e6cf5b05363e1 100644
--- a/.github/workflows/tests-pro-integration.yml
+++ b/.github/workflows/tests-pro-integration.yml
@@ -339,7 +339,7 @@ jobs:
           AWS_DEFAULT_REGION: "us-east-1"
           JUNIT_REPORTS_FILE: "pytest-junit-community-${{ matrix.group }}.xml"
           TEST_PATH: "../../localstack/tests/aws/"  # TODO: run tests in tests/integration
-          PYTEST_ARGS: "${{ env.TINYBIRD_PYTEST_ARGS }}${{ env.TESTSELECTION_PYTEST_ARGS }}--splits ${{ strategy.job-total }} --group ${{ matrix.group }} --durations-path ../../localstack/.test_durations --store-durations"
+          PYTEST_ARGS: "${{ env.TINYBIRD_PYTEST_ARGS }}${{ env.TESTSELECTION_PYTEST_ARGS }}--splits ${{ strategy.job-total }} --group ${{ matrix.group }} --durations-path ../../localstack/.test_durations --store-durations --ignore tests/aws/services/cloudformation/v2"
         working-directory: localstack-pro
         run: |
           # Remove the host tmp folder (might contain remnant files with different permissions)

From 6135c93520726ae8b4801823d9a91f7f59882416 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sun, 27 Jul 2025 20:09:21 +0100
Subject: [PATCH 15/18] Remove accidental unskip

---
 .../services/cloudformation/v2/ported_from_v1/api/test_stacks.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
index 3c0ad16202fc6..b65f0fae31ebe 100644
--- a/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/v2/ported_from_v1/api/test_stacks.py
@@ -910,6 +910,7 @@ def test_stack_deploy_order(deploy_cfn_template, aws_client, snapshot, deploy_or
     snapshot.match("events", filtered_events)
 
 
+@pytest.mark.skip(reason="CFNV2:DescribeStack")
 @markers.snapshot.skip_snapshot_verify(
     paths=[
         # TODO: this property is present in the response from LocalStack when

From d5cc6a64deb80d1e74b7fa4235562e6a05738797 Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sun, 27 Jul 2025 22:39:54 +0100
Subject: [PATCH 16/18] Implement list_stack_resources

---
 .../services/cloudformation/v2/provider.py    | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/localstack-core/localstack/services/cloudformation/v2/provider.py b/localstack-core/localstack/services/cloudformation/v2/provider.py
index 1c21ede098fc1..ee2b6f23aab97 100644
--- a/localstack-core/localstack/services/cloudformation/v2/provider.py
+++ b/localstack-core/localstack/services/cloudformation/v2/provider.py
@@ -34,6 +34,7 @@
     IncludePropertyValues,
     InsufficientCapabilitiesException,
     InvalidChangeSetStatusException,
+    ListStackResourcesOutput,
     ListStacksOutput,
     LogicalResourceId,
     NextToken,
@@ -46,6 +47,7 @@
     StackName,
     StackNameOrId,
     StackResourceDetail,
+    StackResourceSummary,
     StackStatus,
     StackStatusFilter,
     TemplateStage,
@@ -658,6 +660,29 @@ def list_stacks(
         stacks = [select_attributes(stack, attrs) for stack in stacks]
         return ListStacksOutput(StackSummaries=stacks)
 
+    @handler("ListStackResources")
+    def list_stack_resources(
+        self, context: RequestContext, stack_name: StackName, next_token: NextToken = None, **kwargs
+    ) -> ListStackResourcesOutput:
+        result = self.describe_stack_resources(context, stack_name)
+
+        resources = []
+        for resource in result.get("StackResources", []):
+            resources.append(
+                StackResourceSummary(
+                    LogicalResourceId=resource["LogicalResourceId"],
+                    PhysicalResourceId=resource["PhysicalResourceId"],
+                    ResourceType=resource["ResourceType"],
+                    LastUpdatedTimestamp=resource["Timestamp"],
+                    ResourceStatus=resource["ResourceStatus"],
+                    ResourceStatusReason=resource.get("ResourceStatusReason"),
+                    DriftInformation=resource.get("DriftInformation"),
+                    ModuleInfo=resource.get("ModuleInfo"),
+                )
+            )
+
+        return ListStackResourcesOutput(StackResourceSummaries=resources)
+
     @handler("DescribeStackResource")
     def describe_stack_resource(
         self,

From aabdeac3b65f31c46fd163b750f77ec6e34cacbc Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Sun, 27 Jul 2025 22:51:12 +0100
Subject: [PATCH 17/18] Make sure update method of queue policy correctly sets
 physical resource id

---
 .../services/sqs/resource_providers/aws_sqs_queuepolicy.py    | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/localstack-core/localstack/services/sqs/resource_providers/aws_sqs_queuepolicy.py b/localstack-core/localstack/services/sqs/resource_providers/aws_sqs_queuepolicy.py
index cc7bdecfa9254..40dd99191b659 100644
--- a/localstack-core/localstack/services/sqs/resource_providers/aws_sqs_queuepolicy.py
+++ b/localstack-core/localstack/services/sqs/resource_providers/aws_sqs_queuepolicy.py
@@ -104,7 +104,9 @@ def update(
             policy = json.dumps(model["PolicyDocument"])
             sqs.set_queue_attributes(QueueUrl=queue, Attributes={"Policy": policy})
 
+        model["Id"] = request.previous_state["Id"]
+
         return ProgressEvent(
             status=OperationStatus.SUCCESS,
-            resource_model=request.desired_state,
+            resource_model=model,
         )

From 481143cbf4a51a4e5c6336dac8b6e4647f0b511d Mon Sep 17 00:00:00 2001
From: Simon Walker <simon.walker@localstack.cloud>
Date: Mon, 28 Jul 2025 05:02:33 +0100
Subject: [PATCH 18/18] Correct skip path

---
 .github/workflows/tests-pro-integration.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/tests-pro-integration.yml b/.github/workflows/tests-pro-integration.yml
index e6cf5b05363e1..d97f74beab71c 100644
--- a/.github/workflows/tests-pro-integration.yml
+++ b/.github/workflows/tests-pro-integration.yml
@@ -339,7 +339,7 @@ jobs:
           AWS_DEFAULT_REGION: "us-east-1"
           JUNIT_REPORTS_FILE: "pytest-junit-community-${{ matrix.group }}.xml"
           TEST_PATH: "../../localstack/tests/aws/"  # TODO: run tests in tests/integration
-          PYTEST_ARGS: "${{ env.TINYBIRD_PYTEST_ARGS }}${{ env.TESTSELECTION_PYTEST_ARGS }}--splits ${{ strategy.job-total }} --group ${{ matrix.group }} --durations-path ../../localstack/.test_durations --store-durations --ignore tests/aws/services/cloudformation/v2"
+          PYTEST_ARGS: "${{ env.TINYBIRD_PYTEST_ARGS }}${{ env.TESTSELECTION_PYTEST_ARGS }}--splits ${{ strategy.job-total }} --group ${{ matrix.group }} --durations-path ../../localstack/.test_durations --store-durations --ignore ../../localstack/tests/aws/services/cloudformation/v2"
         working-directory: localstack-pro
         run: |
           # Remove the host tmp folder (might contain remnant files with different permissions)