migrate: stacks do not generate from from CloudWatch alarms due to tags property

[robertkatz4]

Describe the bug

stacks do not generate from from CloudWatch alarms due to tags property

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Version

No response

Expected Behavior

I wanted to generate a stack from a generated CloudFormation template, including a CloudWatch::Alarm, with the cdk migrate command

Current Behavior

Stack could not be generated because Tags is not a valid property for resource CloudWatchAlarm

Reproduction Steps

Hard to reproduce exactly... going from ClickOps to IaC is the business purpose.

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.171.0 (build 4957967)

Framework Version

No response

Node.js Version

v22.9.0

OS

MacOS 12.6.8 (really)

Language

TypeScript

Language Version

v22.9.0

Other information

cdk migrate --stack-name abc123-1 --from-path ./abc123-925472.yaml --language typescript
This command is an experimental feature.
 ❌  Migrate failed for `abc123-1`: Stack could not be generated because Tags is not a valid property for resource CloudWatchAlarm.... of type AWS::CloudWatch::Alarm

aws/aws-cdk#29759
perhaps "command is experimental" should be taken seriously.

[pahud]

Root Cause:

• The error seemsed to be generated by the cdk-from-cfn package

aws-cdk-cli/packages/aws-cdk/lib/commands/migrate.ts

Lines 98 to 112 in a1fbefe

	/**
	* Generates a CDK stack file.
	* @param template The template to translate into a CDK stack
	* @param stackName The name to assign to the stack
	* @param language The language to generate the stack in
	* @returns A string representation of a CDK stack file
	*/
	export function generateStack(template: string, stackName: string, language: string) {
	const formattedStackName = `${camelCase(decamelize(stackName), { pascalCase: true })}Stack`;
	try {
	return cdk_from_cfn.transmute(template, language, formattedStackName);
	} catch (e) {
	throw new ToolkitError(`${formattedStackName} could not be generated because ${(e as Error).message}`);
	}
	}

• The validation is failing because the package's schema for AWS::CloudWatch::Alarm doesn't recognize the Tags property
• This is despite CloudFormation now supporting tags for CloudWatch Alarms

Fix Location: The fix needs to be made in the cdk-from-cfn package to update its CloudFormation resource schemas to recognize Tags as a valid property for AWS::CloudWatch::Alarm resources.

I am reaching out the core team to take a look. Meanwhile, can you update your AWS CLI to the latest version and let me know if this issue still exists?