fix(cfn-include): NestedStack's Parameters are not converted to strin…

…gs (aws#15098)

When we include a NestedStack when creating a CfnInclude instance,
the conversion of the Parameters property of the AWS::CloudFormation::Stack resource is performed manually
(because of the eventuality that one of those Parameters was also requested to be removed when including the nested stack).
In that manual conversion, we did not correctly convert the values to strings,
which is what the underlying CfnStack class expects.
And so, if the parent stack passed a non-string primitive value to a nested stack Parameter,
like a number or boolean, including the nested stack would fail with a validation exception.

Fixes aws#15092

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/cloudformation-include/lib/cfn-include.ts

@@ -682,8 +682,8 @@ export class CfnInclude extends core.CfnElement {
  const nestedStackProps = cfnParser.parseValue(nestedStackAttributes.Properties);
  const nestedStack = new core.NestedStack(this, nestedStackId, {
  parameters: this.parametersForNestedStack(nestedStackProps.Parameters, nestedStackId),
- notificationArns: nestedStackProps.NotificationArns,
- timeout: nestedStackProps.Timeout,
+ notificationArns: cfn_parse.FromCloudFormation.getStringArray(nestedStackProps.NotificationARNs).value,
+ timeout: this.timeoutForNestedStack(nestedStackProps.TimeoutInMinutes),
  });
  const template = new CfnInclude(nestedStack, nestedStackId, this.nestedStacksToInclude[nestedStackId]);
  this.nestedStacks[nestedStackId] = { stack: nestedStack, includedTemplate: template };
@@ -694,7 +694,7 @@ export class CfnInclude extends core.CfnElement {
  return nestedStackResource;
  }
 
- private parametersForNestedStack(parameters: any, nestedStackId: string): { [key: string]: any } | undefined {
+ private parametersForNestedStack(parameters: any, nestedStackId: string): { [key: string]: string } | undefined {
  if (parameters == null) {
  return undefined;
  }
@@ -703,12 +703,20 @@ export class CfnInclude extends core.CfnElement {
  const ret: { [key: string]: string } = {};
  for (const paramName of Object.keys(parameters)) {
  if (!(paramName in parametersToReplace)) {
- ret[paramName] = parameters[paramName];
+ ret[paramName] = cfn_parse.FromCloudFormation.getString(parameters[paramName]).value;
  }
  }
  return ret;
  }
 
+ private timeoutForNestedStack(value: any): core.Duration | undefined {
+ if (value == null) {
+ return undefined;
+ }
+
+ return core.Duration.minutes(cfn_parse.FromCloudFormation.getNumber(value).value);
+ }
+
  private overrideLogicalIdIfNeeded(element: core.CfnElement, id: string): void {
  if (this.preserveLogicalIds) {
  element.overrideLogicalId(id);

packages/@aws-cdk/cloudformation-include/test/nested-stacks.test.ts

@@ -334,6 +334,28 @@ describe('CDK Include for nested stacks', () => {
  }).toThrow(/Nested Stack 'AnotherChildStack' was not included in the parent template/);
  });
 
+ test('correctly handles references in nested stacks Parameters', () => {
+ new inc.CfnInclude(stack, 'ParentStack', {
+ templateFile: testTemplateFilePath('cross-stack-refs.json'),
+ loadNestedStacks: {
+ 'ChildStack': {
+ templateFile: testTemplateFilePath('child-import-stack.json'),
+ },
+ },
+ });
+
+ expect(stack).toHaveResourceLike('AWS::CloudFormation::Stack', {
+ "Parameters": {
+ "Param1": {
+ "Ref": "Param",
+ },
+ "Param2": {
+ "Fn::GetAtt": ["Bucket", "Arn"],
+ },
+ },
+ });
+ });
+
  test('correctly handles renaming of references across nested stacks', () => {
  const parentTemplate = new inc.CfnInclude(stack, 'ParentStack', {
  templateFile: testTemplateFilePath('cross-stack-refs.json'),
@@ -386,15 +408,12 @@ describe('CDK Include for nested stacks', () => {
  });
 
  test("handles Metadata, DeletionPolicy, and UpdateReplacePolicy attributes of the nested stack's resource", () => {
- const cfnTemplate = new inc.CfnInclude(stack, 'ParentStack', {
+ new inc.CfnInclude(stack, 'ParentStack', {
  templateFile: testTemplateFilePath('parent-with-attributes.json'),
  loadNestedStacks: {
  'ChildStack': {
  templateFile: testTemplateFilePath('child-import-stack.json'),
  },
- 'AnotherChildStack': {
- templateFile: testTemplateFilePath('child-import-stack.json'),
- },
  },
  });
 
@@ -408,20 +427,50 @@ describe('CDK Include for nested stacks', () => {
  ],
  "UpdateReplacePolicy": "Retain",
  }, ResourcePart.CompleteDefinition);
-
- cfnTemplate.getNestedStack('AnotherChildStack');
  });
 
  test('correctly parses NotificationsARNs, Timeout', () => {
  new inc.CfnInclude(stack, 'ParentStack', {
  templateFile: testTemplateFilePath('parent-with-attributes.json'),
+ loadNestedStacks: {
+ 'ChildStack': {
+ templateFile: testTemplateFilePath('custom-resource.json'),
+ },
+ 'AnotherChildStack': {
+ templateFile: testTemplateFilePath('custom-resource.json'),
+ },
+ },
  });
 
  expect(stack).toHaveResourceLike('AWS::CloudFormation::Stack', {
- "TemplateURL": "https://cfn-templates-set.s3.amazonaws.com/child-import-stack.json",
  "NotificationARNs": ["arn1"],
  "TimeoutInMinutes": 5,
  });
+ expect(stack).toHaveResourceLike('AWS::CloudFormation::Stack', {
+ "NotificationARNs": { "Ref": "ArrayParam" },
+ "TimeoutInMinutes": {
+ "Fn::Select": [0, {
+ "Ref": "ArrayParam",
+ }],
+ },
+ });
+ });
+
+ test('can ingest a NestedStack with a Number CFN Parameter passed as a number', () => {
+ new inc.CfnInclude(stack, 'MyScope', {
+ templateFile: testTemplateFilePath('parent-number-in-child-params.yaml'),
+ loadNestedStacks: {
+ 'NestedStack': {
+ templateFile: testTemplateFilePath('child-with-number-parameter.yaml'),
+ },
+ },
+ });
+
+ expect(stack).toHaveResourceLike('AWS::CloudFormation::Stack', {
+ "Parameters": {
+ "Number": "60",
+ },
+ });
  });
 
  test('can lazily include a single child nested stack', () => {

packages/@aws-cdk/cloudformation-include/test/test-templates/nested/child-with-number-parameter.yaml

@@ -0,0 +1,9 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Parameters:
+ Number:
+ Type: Number
+Resources:
+ S3Bucket:
+ Type: AWS::S3::Bucket
+ Properties:
+ BucketName: 'testbucket1234unique'

packages/@aws-cdk/cloudformation-include/test/test-templates/nested/parent-number-in-child-params.yaml

@@ -0,0 +1,8 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Resources:
+ NestedStack:
+ Type: AWS::CloudFormation::Stack
+ Properties:
+ TemplateURL: 'https://s3.amazonaws.com/masonme-cdk-test/templates/nested-bucket.yaml'
+ Parameters:
+ Number: 60

packages/@aws-cdk/cloudformation-include/test/test-templates/nested/parent-with-attributes.json

@@ -1,9 +1,20 @@
 {
+ "Parameters": {
+ "ArrayParam": {
+ "Type": "CommaDelimitedList"
+ }
+ },
  "Resources": {
  "ChildStack": {
  "Type": "AWS::CloudFormation::Stack",
  "Properties": {
- "TemplateURL": "https://cfn-templates-set.s3.amazonaws.com/child-import-stack.json"
+ "TemplateURL": "https://cfn-templates-set.s3.amazonaws.com/child-import-stack.json",
+ "NotificationARNs": { "Ref": "ArrayParam" },
+ "TimeoutInMinutes": {
+ "Fn::Select": [0, {
+ "Ref": "ArrayParam"
+ }]
+ }
  },
  "DependsOn": [
  "AnotherChildStack"
@@ -23,4 +34,4 @@
  }
  }
  }
-}
+}