rds: `DatabaseInstanceFromSnapshot `doesn't expose `DBClusterSnapshotIdentifier`

[BwL1289]

Describe the bug

The DatabaseInstanceFromSnapshot doesn't expose the DBClusterSnapshotIdentifier attribute so without a workaround, you can't create a db instance from a cluster snapshot.

Regression Issue

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

Last Known Working CDK Version

No response

Expected Behavior

DBClusterSnapshotIdentifier to be exposed via DatabaseInstanceFromSnapshot for example:

dev_db_instance = rds.DatabaseInstanceFromSnapshot(
            self,
            "DatabaseInstanceFromSnapshot",
            cluster_snapshot_identifier="cluster-snapshot-id",
            vpc=vpc,
            parameter_group=parameter_group,
            engine=rds.DatabaseInstanceEngine.mysql(version=self.engine_vsn),
            subnet_group=subnet_group,
            vpc_subnets=ec2.SubnetSelection(subnet_type=ec2.SubnetType.PUBLIC),
            storage_type=rds.StorageType.GP2,
            auto_minor_version_upgrade=True,
            security_groups=[security_group],
            option_group=option_group,
        )

Current Behavior

Only the snapshot_identifier is exposed.

Reproduction Steps

Try to create an rds.DatabaseInstanceFromSnapshot with a cluster snapshot id.

Possible Solution

No response

Additional Information/Context

The workaround is the following:

from typing import cast

dev_db_instance = rds.DatabaseInstanceFromSnapshot(...)

cfn_db = cast(rds.CfnDBInstance, dev_db_instance.node.default_child)
cfn_db.db_cluster_snapshot_identifier = snapshot_identifier
cfn_db.db_snapshot_identifier = None

CDK CLI Version

2.180.0

Framework Version

No response

Node.js Version

v22.12.0

OS

MacOS

Language

Python

Language Version

No response

Other information

No response

[pahud]

Thanks for the report.

Solution approach:

To properly fix this issue, we would need to:

1. Update the DatabaseInstanceFromSnapshotProps interface to add a new optional property clusterSnapshotIdentifier
2. Modify the DatabaseInstanceFromSnapshot class to handle this property and pass it to the underlying CfnDBInstance
3. Add validation to ensure that users don't specify both snapshotIdentifier and clusterSnapshotIdentifier at the same time
4. Update any relevant documentation

Python Workaround:

from typing import cast

# Create your DB instance from snapshot as usual
dev_db_instance = rds.DatabaseInstanceFromSnapshot(
    self,
    "DatabaseInstanceFromSnapshot",
    vpc=vpc,
    parameter_group=parameter_group,
    engine=rds.DatabaseInstanceEngine.mysql(version=self.engine_vsn),
    subnet_group=subnet_group,
    vpc_subnets=ec2.SubnetSelection(subnet_type=ec2.SubnetType.PUBLIC),
    storage_type=rds.StorageType.GP2,
    auto_minor_version_upgrade=True,
    security_groups=[security_group],
    option_group=option_group,
    # Note: we don't use snapshotIdentifier here as we'll override it
)

# Cast to the L1 construct (CfnDBInstance) and modify properties directly
cfn_db = cast(rds.CfnDBInstance, dev_db_instance.node.default_child)
cfn_db.db_cluster_snapshot_identifier = "cluster-snapshot-id"  # Your cluster snapshot ID here
cfn_db.db_snapshot_identifier = None  # Clear the regular snapshot identifier

TypeScript Workaround:

// Create your DB instance from snapshot as usual
const devDbInstance = new rds.DatabaseInstanceFromSnapshot(this, 'DatabaseInstanceFromSnapshot', {
  vpc,
  parameterGroup,
  engine: rds.DatabaseInstanceEngine.mysql({version: engineVsn}),
  subnetGroup,
  vpcSubnets: {subnetType: ec2.SubnetType.PUBLIC},
  storageType: rds.StorageType.GP2,
  autoMinorVersionUpgrade: true,
  securityGroups: [securityGroup],
  optionGroup,
  // Note: we don't use snapshotIdentifier here as we'll override it
});

// Get the L1 construct (CfnDBInstance) and modify properties directly
const cfnDb = devDbInstance.node.defaultChild as rds.CfnDBInstance;
cfnDb.dbClusterSnapshotIdentifier = "cluster-snapshot-id"; // Your cluster snapshot ID here
cfnDb.dbSnapshotIdentifier = undefined; // Clear the regular snapshot identifier

Making this a p2 and we welcome PRs.