Cannot create PostgreSQL with CloudFormation but works with web interface - amazon-web-services

Question

I'm trying to create a Serverless V2 Aurora PostgreSQL cluster and an instance with CloudFormation.
It works fine when using the AWS web interface but when using CloudFormation (trough Serverless) I get
Error: CREATE_FAILED: auroraCluster (AWS::RDS::DBCluster) Resource
handler returned message: "The engine mode serverless you requested is
currently unavailable.
CF Template:
# Database
auroraCluster:
Type: AWS::RDS::DBCluster
Properties:
AutoMinorVersionUpgrade: 'true'
AvailabilityZones:
- eu-north-1a
- eu-north-1b
- eu-north-1c
DatabaseName:
publisher
DeletionProtection: !If [isProd, 'true', 'false']
Engine: aurora-postgresql
EngineMode: serverless
EngineVersion: '14.6'
auroraInstance:
Type: AWS::RDS::DBInstance
Properties:
AllowMajorVersionUpgrade: !If [isProd, 'true', 'false']
AutoMinorVersionUpgrade: 'true'
AvailabilityZone: !Sub ${AWS::Region}a
DBClusterIdentifier: !Ref auroraCluster
DBInstanceIdentifier: ${self:service}-rds-${sls:stage}
DeleteAutomatedBackups: !If [isProd, 'false', 'true']
DeletionProtection: !If [isProd, 'true', 'false']
Engine: aurora-postgresql
ManageMasterUserPassword: 'true'
MasterUsername: postgres
MasterUserSecret:
SecretArn: !Ref secretRds

Answer 1

Serverless aurora for postgress 14.6 is only supported for serverless v2. This requires different setup then you have. For example, you have to provide ServerlessV2ScalingConfiguration, delete EngineMode and use DBInstanceClass set to db.serverless. For example:
Resources:
auroraCluster:
Type: AWS::RDS::DBCluster
Properties:
#AutoMinorVersionUpgrade: 'true'
DatabaseName:
publisher
Engine: aurora-postgresql
EngineVersion: '14.6'
MasterUsername: "trdyd"
MasterUserPassword: "gfsdg344231"
ServerlessV2ScalingConfiguration:
MinCapacity: 1
MaxCapacity: 4
auroraInstance:
Type: 'AWS::RDS::DBInstance'
Properties:
Engine: aurora-postgresql
DBInstanceClass: db.serverless
DBClusterIdentifier: !Ref auroraCluster
Obviously you have to adjust the above example, which works, to what exactly you need, taking into account serverless v2 capabilities.