Requested attribute SecretArn does not exist in schema for AWS::RDS::DBCluster

[TomasChmelik]

According to the AWS documentation there should be "SecretArn" attribute on DBCluster resource: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-dbcluster.html#aws-resource-rds-dbcluster-return-values

It is a bit worrisome that its description is "Property description not available." but shouldn't this be available in CloudFormation?

When ManageMasterUserPassword is se to true the RDS will create new secret in secret manager which isn't referencable anywhere in CloudFormation template, which is where the RDS cluster SecretArn attribute comes in

{
	"Resources": {
		"DatabaseCluster": {
			"Type": "AWS::RDS::DBCluster",
			"Properties": {
				"ManageMasterUserPassword": true,
				// other properties
			}
		}
	},
	"Outputs": {
		"ClusterSecretArn": {
			"Value": {
				"Fn::Sub": "${DatabaseCluster.SecretArn}"
			},
			"Export": {
				"Name": "cluster-secret-arn"
			}
		}
	},
}