aws_db_instance - instance always created in default VPC

[wilb]

Hi there,

I'm trying to provision an RDS instance within a VPC I've created within my terraform, however I don't seem to be able to do so - the instance gets created in my default AWS VPC and I get the error:

"aws_db_instance.XX-XX: Error: Error creating DB Instance: InvalidParameterCombination: DB Instance is in vpc-d7XXXXXX, but Ec2 Security Group sg-a9XXXXXX is in vpc-d5XXXXXX"

My test config is as follows:

resource "aws_db_instance" "XXXXXXXX" {
identifier = "XXXXXXXX"
engine = "mysql"
engine_version = "5.5.38"
instance_class = "db.m1.small"
multi_az = true
allocated_storage = "50"
name = "XXXXXXXX"
username = "root"
password = "XXXXXXXX"
vpc_security_group_ids = [ "${aws_security_group.XXXXXXXX.id}" ]
backup_retention_period = 7
}

I envisaged that by specifying "vpc_security_group_ids" to match a security group within the VPC that would dictate where the instance was created, but this doesn't appear to be the case.

The VPC in question is created succesfully and I'm creating EC2 resources in it without issue. Currently using terraform 0.2.2, not tested with a master build yet.

[wilb]

Is this due to a lack of DB subnet groups being created for the VPC? I don't see a way to manually enforce the creation of these when defining a VPC or subnet.

I have just reapplied my config without the RDS step in place and gone through the creation process via the AWS web console - it looks like I manually need to create a DB subnet group before I can proceed with the RDS creation in that VPC... so I've tried manually creating the subnet group, re-enabled the RDS part of my config and tried to reapply but again I get the same error message.

Am I just trying to do something that isn't yet supported?

[buth]

Subnet groups have not been supported in a released version yet; added them in pull request #295.

[wilb]

Aah cool, I'll build it and give it a go. Thanks.

[wilb]

Awesome - working exactly as expected. I'll not close the bug as obviously its an issue until your PR is merged.

Thanks 👍