localstack · silv-io · Dec 23, 2025 · Dec 10, 2025 · Dec 10, 2025 · Dec 15, 2025
@@ -1216,6 +1216,15 @@ def populate_edge_configuration(
 # EXPERIMENTAL
 CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES = is_env_not_false("CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES")
 
+# Comma-separated list of resource type names that CloudFormation will ignore on stack creation
+CFN_IGNORE_UNSUPPORTED_TYPE_CREATE = parse_comma_separated_list(
+    "CFN_IGNORE_UNSUPPORTED_TYPE_CREATE"
+)
+# Comma-separated list of resource type names that CloudFormation will ignore on stack update
+CFN_IGNORE_UNSUPPORTED_TYPE_UPDATE = parse_comma_separated_list(
+    "CFN_IGNORE_UNSUPPORTED_TYPE_UPDATE"
+)
+
 # Decrease the waiting time for resource deployment
 CFN_NO_WAIT_ITERATIONS: str | int | None = os.environ.get("CFN_NO_WAIT_ITERATIONS")
 

@@ -33,6 +33,9 @@
     PreprocProperties,
     PreprocResource,
 )
+from localstack.services.cloudformation.engine.v2.unsupported_resource import (
+    should_ignore_unsupported_resource_type,
+)
 from localstack.services.cloudformation.resource_provider import (
     Credentials,
     OperationStatus,
@@ -512,7 +515,9 @@ def _execute_resource_action(
                     resource_model={},
                     message=f"Resource provider operation failed: {reason}",
                 )
-        elif config.CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES:
+        elif should_ignore_unsupported_resource_type(
+            resource_type=resource_type, change_set_type=self._change_set.change_set_type
+        ):
             log_not_available_message(
                 resource_type,
                 f'No resource provider found for "{resource_type}"',

@@ -50,6 +50,9 @@
     extract_dynamic_reference,
     perform_dynamic_reference_lookup,
 )
+from localstack.services.cloudformation.engine.v2.unsupported_resource import (
+    should_ignore_unsupported_resource_type,
+)
 from localstack.services.cloudformation.engine.validations import ValidationError
 from localstack.services.cloudformation.stores import (
     exports_map,
@@ -274,6 +277,7 @@ def _deployed_property_value_of(
                 f"No deployed instances of resource '{resource_logical_id}' were found"
             )
         properties = resolved_resource.get("Properties", {})
+        resource_type = resolved_resource.get("Type")
         # TODO support structured properties, e.g. NestedStack.Outputs.OutputName
         property_value: Any | None = get_value_from_path(properties, property_name)
 
@@ -286,7 +290,10 @@ def _deployed_property_value_of(
                     f"Accessing property '{property_name}' from '{resource_logical_id}' resulted in a non-string value nor list"
                 )
             return property_value
-        elif config.CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES:
+        elif resource_type and should_ignore_unsupported_resource_type(
+            resource_type=resource_type,
+            change_set_type=getattr(self._change_set, "change_set_type", None),
+        ):
             return MOCKED_REFERENCE
 
         return property_value

@@ -1,9 +1,11 @@
-from localstack.services.cloudformation.engine.v2.change_set_model import (
-    NodeResource,
-)
+from localstack.aws.api.cloudformation import ChangeSetType
+from localstack.services.cloudformation.engine.v2.change_set_model import NodeResource
 from localstack.services.cloudformation.engine.v2.change_set_model_visitor import (
     ChangeSetModelVisitor,
 )
+from localstack.services.cloudformation.engine.v2.unsupported_resource import (
+    should_ignore_unsupported_resource_type,
+)
 from localstack.services.cloudformation.resources import AWS_AVAILABLE_CFN_RESOURCES
 from localstack.utils.catalog.catalog import (
     AwsServicesSupportStatus,
@@ -81,17 +83,23 @@ def _build_resource_failure_message(
 
 
 class ChangeSetResourceSupportChecker(ChangeSetModelVisitor):
+    change_set_type: ChangeSetType | str | None
     catalog: CatalogPlugin
 
     TITLE_MESSAGE = "Unsupported resources detected:"
 
-    def __init__(self):
+    def __init__(self, change_set_type: ChangeSetType | str | None = None):
         self._resource_failure_messages: dict[str, str] = {}
+        self.change_set_type = change_set_type
         self.catalog = get_aws_catalog()
 
     def visit_node_resource(self, node_resource: NodeResource):
         resource_type = node_resource.type_.value
-        if resource_type not in self._resource_failure_messages:
+        ignore_unsupported = should_ignore_unsupported_resource_type(
+            resource_type=resource_type, change_set_type=self.change_set_type
+        )
+
+        if resource_type not in self._resource_failure_messages and not ignore_unsupported:
             if resource_type not in AWS_AVAILABLE_CFN_RESOURCES:
                 # Ignore non-AWS resources
                 pass

@@ -0,0 +1,19 @@
+from __future__ import annotations
+
+from localstack import config
+from localstack.aws.api.cloudformation import ChangeSetType
+
+
+def should_ignore_unsupported_resource_type(
+    resource_type: str, change_set_type: ChangeSetType | str | None
+) -> bool:
+    if config.CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES:
+        return True
+
+    match change_set_type:
+        case ChangeSetType.CREATE:
+            return resource_type in config.CFN_IGNORE_UNSUPPORTED_TYPE_CREATE
+        case ChangeSetType.UPDATE | ChangeSetType.IMPORT:
+            return resource_type in config.CFN_IGNORE_UNSUPPORTED_TYPE_UPDATE
+        case _:
+            return False
@@ -427,7 +427,9 @@ def _setup_change_set_model(
         change_set.processed_template = transformed_after_template
 
         if not config.CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES:
-            support_visitor = ChangeSetResourceSupportChecker()
+            support_visitor = ChangeSetResourceSupportChecker(
+                change_set_type=change_set.change_set_type
+            )
             support_visitor.visit(change_set.update_model.node_template)
             failure_messages = support_visitor.failure_messages
             if failure_messages:

diff --git a/tests/integration/test_catalog.py b/tests/integration/test_catalog.py
@@ -86,6 +86,97 @@ def testing_catalog(monkeypatch):
     return plugin
 
 
+@markers.aws.only_localstack
+def test_ignore_unsupported_resources_toggle(testing_catalog, aws_client, monkeypatch, cleanups):
+    unsupported_resource = "AWS::LatestService::NotSupported"
+
+    def _create_change_set(stack_name: str, template_body: str):
+        change_set_name = f"cs-{short_uid()}"
+        response = aws_client.cloudformation.create_change_set(
+            StackName=stack_name,
+            ChangeSetName=change_set_name,
+            TemplateBody=template_body,
+            ChangeSetType="CREATE",
+        )
+        return response["Id"], response["StackId"]
+
+    def _wait_for_failed_change_set(change_set_id: str):
+        def _describe():
+            result = aws_client.cloudformation.describe_change_set(ChangeSetName=change_set_id)
+            status = result["Status"]
+            if status == "FAILED":
+                return result
+            if status == "CREATE_COMPLETE":
+                pytest.fail("expected change set creation to fail")
+            raise Exception("still waiting for change set to fail")
+
+        return retry(_describe, retries=15, sleep=2)
+
+    def _wait_for_complete_change_set(change_set_id: str):
+        def _describe():
+            result = aws_client.cloudformation.describe_change_set(ChangeSetName=change_set_id)
+            status = result["Status"]
+            if status == "CREATE_COMPLETE":
+                return result
+            if status == "FAILED":
+                pytest.fail(f"change set unexpectedly failed: {result.get('StatusReason')}")
+            raise Exception("still waiting for change set")
+
+        return retry(_describe, retries=15, sleep=2)
+
+    def _wait_for_stack_status(stack_name: str, expected: str):
+        def _describe():
+            stack = aws_client.cloudformation.describe_stacks(StackName=stack_name)["Stacks"][0]
+            status = stack["StackStatus"]
+            if status == expected:
+                return stack
+            if status.endswith("FAILED") or "ROLLBACK" in status:
+                pytest.fail(f"stack ended in failure: {status} ({stack.get('StackStatusReason')})")
+            raise Exception("still waiting for stack")
+
+        return retry(_describe, retries=30, sleep=2)
+
+    # template with one supported and one unsupported resource
+    bucket_name = f"cfn-toggle-{short_uid()}"
+    template_body = textwrap.dedent(
+        f"""
+        AWSTemplateFormatVersion: '2010-09-09'
+        Resources:
+          SupportedBucket:
+            Type: AWS::S3::Bucket
+            Properties:
+              BucketName: {bucket_name}
+          Unsupported:
+            Type: {unsupported_resource}
+        """
+    )
+
+    # 1) ignore lists empty -> change set should fail
+    monkeypatch.setattr(config, "CFN_IGNORE_UNSUPPORTED_RESOURCE_TYPES", False)
+    monkeypatch.setattr(config, "CFN_IGNORE_UNSUPPORTED_TYPE_CREATE", [])
+    stack_name_fail = f"stack-fail-{short_uid()}"
+    cs_id_fail, stack_id_fail = _create_change_set(stack_name_fail, template_body)
+    failed_cs = _wait_for_failed_change_set(cs_id_fail)
+    status_reason = failed_cs.get("StatusReason", "")
+    assert ChangeSetResourceSupportChecker.TITLE_MESSAGE in status_reason
+    assert unsupported_resource in status_reason
-    failed_cs = _wait_for_failed_change_set(cs_id_fail)
-    status_reason = failed_cs.get("StatusReason", "")
-    assert ChangeSetResourceSupportChecker.TITLE_MESSAGE in status_reason
-    assert unsupported_resource in status_reason
+    with pytest.raises(WaiterError) as exc_info:
+        aws_client.cloudformation.get_waiter("change_set_create_complete").wait(
+            ChangeSetName=cs_id_fail
+        )
+
+    assert exc_info.value.last_response["Status"] == "FAILED"
+    status_reason = exc_info.value.last_response["StatusReason"]
+    assert ChangeSetResourceSupportChecker.TITLE_MESSAGE in status_reason
+    assert unsupported_resource in status_reason
-    failed_cs = _wait_for_failed_change_set(cs_id_fail)
-    status_reason = failed_cs.get("StatusReason", "")
-    assert ChangeSetResourceSupportChecker.TITLE_MESSAGE in status_reason
-    assert unsupported_resource in status_reason
+    with pytest.raises(WaiterError) as exc_info:
+        aws_client.cloudformation.get_waiter("change_set_create_complete").wait(
+            ChangeSetName=cs_id_fail
+        )
+
+    assert exc_info.value.last_response["Status"] == "FAILED"
+    status_reason = exc_info.value.last_response["StatusReason"]
+    assert ChangeSetResourceSupportChecker.TITLE_MESSAGE in status_reason
+    assert unsupported_resource in status_reason
+    cleanups.append(lambda: aws_client.cloudformation.delete_change_set(ChangeSetName=cs_id_fail))
+    cleanups.append(lambda: aws_client.cloudformation.delete_stack(StackName=stack_id_fail))
+
+    # 2) add unsupported resource to create ignore list -> deployment succeeds and bucket is present
+    monkeypatch.setattr(config, "CFN_IGNORE_UNSUPPORTED_TYPE_CREATE", [unsupported_resource])
+    stack_name_ok = f"stack-ok-{short_uid()}"
+    cs_id_ok, stack_id_ok = _create_change_set(stack_name_ok, template_body)
+    _wait_for_complete_change_set(cs_id_ok)
-    _wait_for_complete_change_set(cs_id_ok)
+    aws_client.cloudformation.get_waiter("change_set_create_complete").wait(ChangeSetName=cs_id_ok)
-    _wait_for_complete_change_set(cs_id_ok)
+    aws_client.cloudformation.get_waiter("change_set_create_complete").wait(ChangeSetName=cs_id_ok)
+    aws_client.cloudformation.execute_change_set(ChangeSetName=cs_id_ok)
+    _wait_for_stack_status(stack_name_ok, "CREATE_COMPLETE")
-    _wait_for_stack_status(stack_name_ok, "CREATE_COMPLETE")
+    aws_client.cloudformation.get_waiter("stack_create_complete").wait(StackName=stack_name_ok)
-    _wait_for_stack_status(stack_name_ok, "CREATE_COMPLETE")
+    aws_client.cloudformation.get_waiter("stack_create_complete").wait(StackName=stack_name_ok)
+
+    buckets = aws_client.s3.list_buckets()["Buckets"]
+    assert any(b["Name"] == bucket_name for b in buckets)
+
+    cleanups.append(lambda: aws_client.cloudformation.delete_stack(StackName=stack_id_ok))
+
+
 @markers.aws.only_localstack
 @pytest.mark.parametrize(
     "unsupported_resource, expected_service",