Extract resource ordering to new submodule

localstack-core/localstack/services/cloudformation/engine/changes.py

@@ -0,0 +1,18 @@
+from typing import Literal, Optional, TypedDict
+
+Action = str
+
+
+class ResourceChange(TypedDict):
+    Action: Action
+    LogicalResourceId: str
+    PhysicalResourceId: Optional[str]
+    ResourceType: str
+    Scope: list
+    Details: list
+    Replacement: Optional[Literal["False"]]
+
+
+class ChangeConfig(TypedDict):
+    Type: str
+    ResourceChange: ResourceChange

localstack-core/localstack/services/cloudformation/engine/resource_ordering.py

@@ -0,0 +1,109 @@
+from collections import OrderedDict
+
+from localstack.services.cloudformation.engine.changes import ChangeConfig
+from localstack.services.cloudformation.engine.parameters import StackParameter
+from localstack.services.cloudformation.engine.template_utils import get_deps_for_resource
+
+
+class NoResourceInStack(ValueError):
+    """Raised when we preprocess the template and do not find a resource"""
+
+    def __init__(self, logical_resource_id: str):
+        msg = f"Template format error: Unresolved resource dependencies [{logical_resource_id}] in the Resources block of the template"
+
+        super().__init__(msg)
+
+
+def order_resources(
+    resources: dict,
+    resolved_parameters: dict[str, StackParameter],
+    resolved_conditions: dict[str, bool],
+    reverse: bool = False,
+) -> OrderedDict:
+    """
+    Given a dictionary of resources, topologically sort the resources based on
+    inter-resource dependencies (e.g. usages of intrinsic functions).
+    """
+    nodes: dict[str, list[str]] = {}
+    for logical_resource_id, properties in resources.items():
+        nodes.setdefault(logical_resource_id, [])
+        deps = get_deps_for_resource(properties, resolved_conditions)
+        for dep in deps:
+            if dep in resolved_parameters:
+                # we only care about other resources
+                continue
+            nodes.setdefault(dep, [])
+            nodes[dep].append(logical_resource_id)
+
+    # implementation from https://dev.to/leopfeiffer/topological-sort-with-kahns-algorithm-3dl1
+    indegrees = {k: 0 for k in nodes.keys()}
+    for dependencies in nodes.values():
+        for dependency in dependencies:
+            indegrees[dependency] += 1
+
+    # Place all elements with indegree 0 in queue
+    queue = [k for k in nodes.keys() if indegrees[k] == 0]
+
+    sorted_logical_resource_ids = []
+
+    # Continue until all nodes have been dealt with
+    while len(queue) > 0:
+        # node of current iteration is the first one from the queue
+        curr = queue.pop(0)
+        sorted_logical_resource_ids.append(curr)
+
+        # remove the current node from other dependencies
+        for dependency in nodes[curr]:
+            indegrees[dependency] -= 1
+
+            if indegrees[dependency] == 0:
+                queue.append(dependency)
+
+    # check for circular dependencies
+    if len(sorted_logical_resource_ids) != len(nodes):
+        raise Exception("Circular dependency found.")
+
+    sorted_mapping = []
+    for logical_resource_id in sorted_logical_resource_ids:
+        if properties := resources.get(logical_resource_id):
+            sorted_mapping.append((logical_resource_id, properties))
+        else:
+            if (
+                logical_resource_id not in resolved_parameters
+                and logical_resource_id not in resolved_conditions
+            ):
+                raise NoResourceInStack(logical_resource_id)
+
+    if reverse:
+        sorted_mapping = sorted_mapping[::-1]
+    return OrderedDict(sorted_mapping)
+
+
+def order_changes(
+    given_changes: list[ChangeConfig],
+    resources: dict,
+    resolved_parameters: dict[str, StackParameter],
+    # TODO: remove resolved conditions somehow
+    resolved_conditions: dict[str, bool],
+    reverse: bool = False,
+) -> list[ChangeConfig]:
+    """
+    Given a list of changes, a dictionary of resources and a dictionary of resolved conditions, topologically sort the
+    changes based on inter-resource dependencies (e.g. usages of intrinsic functions).
+    """
+    ordered_resources = order_resources(
+        resources=resources,
+        resolved_parameters=resolved_parameters,
+        resolved_conditions=resolved_conditions,
+        reverse=reverse,
+    )
+    sorted_changes = []
+    for logical_resource_id in ordered_resources.keys():
+        for change in given_changes:
+            if change["ResourceChange"]["LogicalResourceId"] == logical_resource_id:
+                sorted_changes.append(change)
+                break
+    assert len(sorted_changes) > 0
+    if reverse:
+        sorted_changes = sorted_changes[::-1]
+    return sorted_changes

localstack-core/localstack/services/cloudformation/engine/template_deployer.py

@@ -5,8 +5,7 @@
 import traceback
 import uuid
 from abc import ABC, abstractmethod
-from collections import OrderedDict
-from typing import Literal, Optional, TypedDict
+from typing import Optional
 
 from localstack import config
 from localstack.aws.connect import connect_to
@@ -16,9 +15,14 @@
     get_action_name_for_resource_change,
     remove_none_values,
 )
+from localstack.services.cloudformation.engine.changes import ChangeConfig, ResourceChange
 from localstack.services.cloudformation.engine.entities import Stack, StackChangeSet
 from localstack.services.cloudformation.engine.parameters import StackParameter
 from localstack.services.cloudformation.engine.quirks import VALID_GETATT_PROPERTIES
+from localstack.services.cloudformation.engine.resource_ordering import (
+    order_changes,
+    order_resources,
+)
 from localstack.services.cloudformation.engine.template_utils import (
     AWS_URL_SUFFIX,
     fn_equals_type_conversion,
@@ -63,15 +67,6 @@ class NoStackUpdates(Exception):
     pass
 
 
-class NoResourceInStack(ValueError):
-    """Raised when we preprocess the template and do not find a resource"""
-
-    def __init__(self, logical_resource_id: str):
-        msg = f"Template format error: Unresolved resource dependencies [{logical_resource_id}] in the Resources block of the template"
-
-        super().__init__(msg)
-
-
 # ---------------------
 # CF TEMPLATE HANDLING
 # ---------------------
@@ -784,119 +779,6 @@ def evaluate_resource_condition(conditions: dict[str, bool], resource: dict) ->
 # -----------------------
 
 
-Action = str
-
-
-class ResourceChange(TypedDict):
-    Action: Action
-    LogicalResourceId: str
-    PhysicalResourceId: Optional[str]
-    ResourceType: str
-    Scope: list
-    Details: list
-    Replacement: Optional[Literal["False"]]
-
-
-class ChangeConfig(TypedDict):
-    Type: str
-    ResourceChange: ResourceChange
-
-
-def order_resources(
-    resources: dict,
-    resolved_parameters: dict[str, StackParameter],
-    resolved_conditions: dict[str, bool],
-    reverse: bool = False,
-) -> OrderedDict:
-    """
-    Given a dictionary of resources, topologically sort the resources based on
-    inter-resource dependencies (e.g. usages of intrinsic functions).
-    """
-    nodes: dict[str, list[str]] = {}
-    for logical_resource_id, properties in resources.items():
-        nodes.setdefault(logical_resource_id, [])
-        deps = get_deps_for_resource(properties, resolved_conditions)
-        for dep in deps:
-            if dep in resolved_parameters:
-                # we only care about other resources
-                continue
-            nodes.setdefault(dep, [])
-            nodes[dep].append(logical_resource_id)
-
-    # implementation from https://dev.to/leopfeiffer/topological-sort-with-kahns-algorithm-3dl1
-    indegrees = {k: 0 for k in nodes.keys()}
-    for dependencies in nodes.values():
-        for dependency in dependencies:
-            indegrees[dependency] += 1
-
-    # Place all elements with indegree 0 in queue
-    queue = [k for k in nodes.keys() if indegrees[k] == 0]
-
-    sorted_logical_resource_ids = []
-
-    # Continue until all nodes have been dealt with
-    while len(queue) > 0:
-        # node of current iteration is the first one from the queue
-        curr = queue.pop(0)
-        sorted_logical_resource_ids.append(curr)
-
-        # remove the current node from other dependencies
-        for dependency in nodes[curr]:
-            indegrees[dependency] -= 1
-
-            if indegrees[dependency] == 0:
-                queue.append(dependency)
-
-    # check for circular dependencies
-    if len(sorted_logical_resource_ids) != len(nodes):
-        raise Exception("Circular dependency found.")
-
-    sorted_mapping = []
-    for logical_resource_id in sorted_logical_resource_ids:
-        if properties := resources.get(logical_resource_id):
-            sorted_mapping.append((logical_resource_id, properties))
-        else:
-            if (
-                logical_resource_id not in resolved_parameters
-                and logical_resource_id not in resolved_conditions
-            ):
-                raise NoResourceInStack(logical_resource_id)
-
-    if reverse:
-        sorted_mapping = sorted_mapping[::-1]
-    return OrderedDict(sorted_mapping)
-
-
-def order_changes(
-    given_changes: list[ChangeConfig],
-    resources: dict,
-    resolved_parameters: dict[str, StackParameter],
-    # TODO: remove resolved conditions somehow
-    resolved_conditions: dict[str, bool],
-    reverse: bool = False,
-) -> list[ChangeConfig]:
-    """
-    Given a list of changes, a dictionary of resources and a dictionary of resolved conditions, topologically sort the
-    changes based on inter-resource dependencies (e.g. usages of intrinsic functions).
-    """
-    ordered_resources = order_resources(
-        resources=resources,
-        resolved_parameters=resolved_parameters,
-        resolved_conditions=resolved_conditions,
-        reverse=reverse,
-    )
-    sorted_changes = []
-    for logical_resource_id in ordered_resources.keys():
-        for change in given_changes:
-            if change["ResourceChange"]["LogicalResourceId"] == logical_resource_id:
-                sorted_changes.append(change)
-                break
-    assert len(sorted_changes) > 0
-    if reverse:
-        sorted_changes = sorted_changes[::-1]
-    return sorted_changes
-
-
 class TemplateDeployerBase(ABC):
     def __init__(self, account_id: str, region_name: str, stack):
         self.stack = stack

localstack-core/localstack/services/cloudformation/provider.py

@@ -89,11 +89,13 @@
     StackSet,
 )
 from localstack.services.cloudformation.engine.parameters import strip_parameter_type
-from localstack.services.cloudformation.engine.template_deployer import (
+from localstack.services.cloudformation.engine.resource_ordering import (
     NoResourceInStack,
-    NoStackUpdates,
     order_resources,
 )
+from localstack.services.cloudformation.engine.template_deployer import (
+    NoStackUpdates,
+)
 from localstack.services.cloudformation.engine.template_utils import resolve_stack_conditions
 from localstack.services.cloudformation.engine.transformers import (
     FailedTransformationException,