aws-cloudformation
[AWS::RDS::GlobalCluster] - False positive drift on 'SourceDBClusterIdentifer' property
Name of the resource
AWS::RDS::GlobalCluster
Resource Name
No response
Issue Description
The 'AWS::RDS::GlobalCluster' resource is showing as false positive drift for the 'SourceDBClusterIdentifer' property where the ARN is being passed instead of the cluster identifier/physical resource ID.
According to this AWS documentation, the "SourceDBClusterIdentifier" value should be the Amazon Resource Name (ARN) to use as the primary cluster of the global database. We see that the template is using a Reference to the "AWS::RDS::DBCluster" resource and according to this documentation Ref should be returning the name (DBClusterIdentifier) of the DB cluster, however, is it seen that even if the identifier/name is being passed (either via ref or hardcoded), it is being converted automatically to an ARN causing a false positive drift in CFN.
Expected Behavior
When using Ref or hardcoding the value for the SourceDBClusterIdentifer property, it should not show as Drifted as no manual changes were made outside of CFN
Observed Behavior
When the identifier/name is being passed (either via ref or hardcoded), it is being passed as an ARN causing a false positive drift in CFN: [ { "Type": "AWS::RDS::GlobalCluster", "Resource": "GlobalCluster", "Status": "MODIFIED", "Diff": [ { "PropertyPath": "/SourceDBClusterIdentifier", "ExpectedValue": "name-of-cluster", "ActualValue": "arn:aws:rds:us-east-1:123456789123:cluster:name-of-cluster", "DifferenceType": "NOT_EQUAL" } ] } ]
Test Cases
Create a Global Database cluster for Aurora PostgreSQL, you may use the template from this example in the docs: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-rds-globalcluster.html#aws-resource-rds-globalcluster--examples--Creating_a_Global_Database_cluster_for_Aurora_PostgreSQL
Once the stack has created successfully, run drift detection on the stack and the stack will show as drifted with the AWS::RDS::GlobalCluster showing as modified for the SourceDBClusterIdentifier property
Other Details
No response
