Add the ability to create databases in a existing instance

[geNAZt]

Is your feature request related to a problem? Please describe.
We currently deploy a RD instance with the service broker and get one database back. Our usecase needs multiple databases. Currently the service broker is not able to process such requests.

Describe the solution you'd like
Add a service which allows the use of the broker to create new databases in existing instances by providing the endpoint address, port and username/password

Describe alternatives you've considered
The alternative would use a terraform config inside a helm chart do create a user and database, grant access to the database and generating env variables for the container to pick up

[jaymccon]

I really like this idea, could be implemented with a CloudFormation template that launches a lambda into the RDS VPC and executes it as a custom resource.

[pierreozoux]

For me, this looks like a new plan.
"create a db in an existing RDS"