(rds): support for Aurora Serverless V2

[rpbarnes]

Describe the feature

Please like the original post instead of leaving a +1 comment.

Add CDK support for aurora serverless v2 ideally via the ServerlessCluster construct.

edit there's a few solutions using base cloud formation constructs in the comments. Please see those for a work around.

Currently deploying a Serverless V2 instance via cdk doesn't seem possible.

I've got this far

        enum ServerlessInstanceType {
            SERVERLESS = 'serverless',
        }
        type CustomInstanceType = ServerlessInstanceType | ec2.InstanceType;
        const CustomInstanceType = {
            ...ServerlessInstanceType,
            ...ec2.InstanceType,
        };

        this.serverlessCluster = new DatabaseCluster(
            this,
            'ServerlessClusterV2',
            {
                engine: DatabaseClusterEngine.auroraMysql({
                    version: AuroraMysqlEngineVersion.of(
                        '8.0.mysql_aurora.3.02.0'
                    ), // The new minor version of Database Engine.
                }),
                storageEncrypted: true,
                iamAuthentication: true,
                parameterGroup: ParameterGroup.fromParameterGroupName(
                    this,
                    'rdsClusterPrameterGroup',
                    'default.aurora-mysql8.0'
                ),
                storageEncryptionKey: new Key(this, 'dbEncryptionKey'),
                instanceProps: {
                    instanceType:
                        CustomInstanceType.SERVERLESS as unknown as InstanceType,
                    vpc: props.vpc,
                    vpcSubnets: {
                        subnetType: SubnetType.PRIVATE_ISOLATED,
                    },
                },
            }
        );

but I keep running into this error

Set the Serverless v2 scaling configuration on the parent DB cluster before creating a Serverless v2 DB instance.

Which I can't figure out a way around.

Use Case

Need to create a DB via CDK. I want to use Serverless V2 because of the support for mysql 8.0.

Proposed Solution

No response

Other Information

No response

Acknowledgements

• I may be able to implement this feature request
• This feature might incur a breaking change

CDK version used

2.15.0

Environment details (OS name and version, etc.)

mac OS X

[jvlch]

I found a workaround using a custom resource, uses addDependency on instances to a custom resource that sets the min/max capacity settings

enum ServerlessInstanceType {
  SERVERLESS = 'serverless',
}

type CustomInstanceType = ServerlessInstanceType | ec2.InstanceType;

const CustomInstanceType = { ...ServerlessInstanceType, ...ec2.InstanceType };

const dbClusterInstanceCount: number = 1

const dbCluster = new rds.DatabaseCluster(this, 'DbCluster', {
  engine: rds.DatabaseClusterEngine.auroraPostgres({
    version: rds.AuroraPostgresEngineVersion.VER_13_6,
  }),
  instances: dbClusterInstanceCount,
  instanceProps: {
    vpc: vpc,
    instanceType: CustomInstanceType.SERVERLESS as unknown as ec2.InstanceType,
    autoMinorVersionUpgrade: false,
    publiclyAccessible: false,
    securityGroups: [
      dbSecurityGroup,
    ],
    vpcSubnets: {
      subnets: [vpc.isolatedSubnets[0], vpc.isolatedSubnets[1], vpc.isolatedSubnets[2]]
    },
  },
  credentials: rds.Credentials.fromSecret(dbAdminSecret),
  backup: {
    retention: cdk.Duration.days(7),
    preferredWindow: '08:00-09:00'
  },
  port: 5432,
  cloudwatchLogsExports: ["postgresql"],
  cloudwatchLogsRetention: logs.RetentionDays.SIX_MONTHS,
  subnetGroup: dbSubnetGroup,
  storageEncrypted: true,
  storageEncryptionKey: dbKey,
})


const serverlessV2ScalingConfiguration = {
  MinCapacity: 0.5,
  MaxCapacity: 16,
}

const dbScalingConfigure = new cr.AwsCustomResource(this, 'DbScalingConfigure', {
  onCreate: {
    service: "RDS",
    action: "modifyDBCluster",
    parameters: {
      DBClusterIdentifier: dbCluster.clusterIdentifier,
      ServerlessV2ScalingConfiguration: serverlessV2ScalingConfiguration,
    },
    physicalResourceId: cr.PhysicalResourceId.of(dbCluster.clusterIdentifier)
  },
  onUpdate: {
    service: "RDS",
    action: "modifyDBCluster",
    parameters: {
      DBClusterIdentifier: dbCluster.clusterIdentifier,
      ServerlessV2ScalingConfiguration: serverlessV2ScalingConfiguration,
    },
    physicalResourceId: cr.PhysicalResourceId.of(dbCluster.clusterIdentifier)
  },
  policy: cr.AwsCustomResourcePolicy.fromSdkCalls({
    resources: cr.AwsCustomResourcePolicy.ANY_RESOURCE,
  }),
})

const cfnDbCluster = dbCluster.node.defaultChild as rds.CfnDBCluster
const dbScalingConfigureTarget = dbScalingConfigure.node.findChild("Resource").node.defaultChild as cdk.CfnResource

cfnDbCluster.addPropertyOverride("EngineMode", "provisioned")
dbScalingConfigure.node.addDependency(cfnDbCluster)


for (let i = 1 ; i <= dbClusterInstanceCount ; i++) { 
  (dbCluster.node.findChild(`Instance${i}`) as rds.CfnDBInstance).addDependsOn(dbScalingConfigureTarget)
}

[rpbarnes]

Wo that's cool.

I'll give that a try. Just curious though... Is AWS planning on adding Aurora Serverless V2 setup as proper cdk constructs? I'm happy to wait a bit if I can get the proper thing instead of moving forward with the workaround.

[skinny85]

Yes, this is definitely on our roadmap. Not sure when we're going to get to it though - leaving +1s on the issue will definitely help us prioritize.

We also encourage community contributions. Our "Contributing" guide: https://github.com/aws/aws-cdk/blob/master/CONTRIBUTING.md.

Thanks,
Adam