You can clone with
When you create or get all DBInstance objects in RDS, the DBInstance object does not support having multiple DBSecurityGroup objects associated with the DBInstance. It also does not support multiple DBParameterGroup objects to be associated with the DBInstance.
The DBParameterGroup issue seems to be a non-issue at the moment because as far as I can tell you can't associate multiple DBParameterGroups with a DBInstance at creation time or at modify time.
This bug has been in the code since forever, really. My memory may be incorrect but as I recall in the early days of RDS, you could only have one DBSecurityGroup associated with a DBInstance so perhaps that is where this started. That clearly is no longer the case, though, and this bug needs to be fixed.
Support multiple DBSecurityGroups for DBInstance. Fixes #1086.