Ensure CfnParameter ordering is respected

Fixes an issue where CloudFormation parameter group ordering was not guaranteed

Author: pwrmiller

source/cdk_solution_helper_py/helpers_cdk/aws_solutions/cdk/__init__.py

@@ -29,5 +29,13 @@ class CDKSolution:
     """
 
     def __init__(self, cdk_json_path: Path, qualifier="hnb659fds"):
+        self.qualifier = qualifier
         self.context = SolutionContext(cdk_json_path=cdk_json_path)
-        self.synthesizer = SolutionStackSubstitions(qualifier=qualifier)
+        self.synthesizer = SolutionStackSubstitions(qualifier=self.qualifier)
+
+    def reset(self) -> None:
+        """
+        Get a new synthesizer for this CDKSolution - useful for testing
+        :return: None
+        """
+        self.synthesizer = SolutionStackSubstitions(qualifier=self.qualifier)

source/cdk_solution_helper_py/helpers_cdk/aws_solutions/cdk/interfaces.py

@@ -77,9 +77,12 @@ def metadata(self) -> dict:
         return self._metadata
 
     def _get_metadata(self) -> dict:
-        parameter_groups = list(
-            set([parameter.group for parameter in self._parameters])
-        )
+        pgs = set()
+        parameter_groups = [
+            p.group
+            for p in self._parameters
+            if p.group not in pgs and not pgs.add(p.group)
+        ]
         metadata = {
             "AWS::CloudFormation::Interface": {
                 "ParameterGroups": [

source/tests/cdk_solution_helper/test_stack.py

@@ -14,7 +14,7 @@
 import re
 
 import pytest
-from aws_cdk.core import App
+from aws_cdk.core import App, CfnParameter
 
 from aws_solutions.cdk.stack import (
     SolutionStack,
@@ -113,3 +113,39 @@ def test_solution_stack():
             ]
         }
     }
+
+
+@pytest.mark.parametrize("execution_number", range(5))
+def test_stack_parameter_ordering(execution_number):
+    app = App(context={"SOLUTION_ID": "SO0123"})
+    stack = SolutionStack(app, "stack", "test stack", "test-stack.template")
+
+    param_1 = CfnParameter(stack, "parameter1")
+    param_2 = CfnParameter(stack, "parameter2")
+
+    stack.solutions_template_options.add_parameter(param_1, "parameter 1", "group 1")
+    stack.solutions_template_options.add_parameter(param_2, "parameter 2", "group 2")
+
+    template = app.synth().stacks[0].template
+
+    assert (
+        template["Metadata"]["AWS::CloudFormation::Interface"]["ParameterGroups"][0][
+            "Label"
+        ]["default"]
+        == "group 1"
+    )
+    assert template["Metadata"]["AWS::CloudFormation::Interface"]["ParameterGroups"][0][
+        "Parameters"
+    ] == ["parameter1"]
+    assert (
+        template["Metadata"]["AWS::CloudFormation::Interface"]["ParameterLabels"][
+            "parameter1"
+        ]["default"]
+        == "parameter 1"
+    )
+    assert (
+        template["Metadata"]["AWS::CloudFormation::Interface"]["ParameterLabels"][
+            "parameter2"
+        ]["default"]
+        == "parameter 2"
+    )

source/tests/test_deploy.py

@@ -25,7 +25,9 @@ def cdk_entrypoint():
 
 
 def test_deploy(solution, cdk_entrypoint):
-    from deploy import build_app
+    from deploy import build_app, solution as cdk_solution
+
+    cdk_solution.reset()
 
     extra_context = "EXTRA_CONTEXT"
     source_bucket = "SOURCE_BUCKET"
@@ -40,3 +42,40 @@ def test_deploy(solution, cdk_entrypoint):
         "Yes"
         == stack.template["Mappings"]["Solution"]["Data"]["SendAnonymousUsageData"]
     )
+    assert stack.template["Outputs"]["PersonalizeBucketName"]
+    assert stack.template["Outputs"]["SchedulerTableName"]
+    assert stack.template["Outputs"]["SNSTopicArn"]
+
+
+def test_parameters(solution, cdk_entrypoint):
+    """Ensure parameter ordering is kept"""
+    from deploy import build_app, solution as cdk_solution
+
+    cdk_solution.reset()
+
+    extra_context = "EXTRA_CONTEXT"
+    source_bucket = "SOURCE_BUCKET"
+    synth = build_app({extra_context: extra_context, "BUCKET_NAME": source_bucket})
+    stack = synth.get_stack("PersonalizeStack").template
+
+    assert (
+        stack["Metadata"]["AWS::CloudFormation::Interface"]["ParameterGroups"][0][
+            "Label"
+        ]["default"]
+        == "Solution Configuration"
+    )
+    assert stack["Metadata"]["AWS::CloudFormation::Interface"]["ParameterGroups"][0][
+        "Parameters"
+    ] == ["Email"]
+    assert (
+        stack["Metadata"]["AWS::CloudFormation::Interface"]["ParameterLabels"]["Email"][
+            "default"
+        ]
+        == "Email"
+    )
+    assert (
+        stack["Metadata"]["AWS::CloudFormation::Interface"]["ParameterLabels"][
+            "PersonalizeKmsKeyArn"
+        ]["default"]
+        == "(Optional) KMS key ARN used to encrypt Datasets managed by Amazon Personalize"
+    )