camptocamp / terraform-aws-rds-nlb

Module to update NLB target-groups with IP addresses of RDS db instances

This module will track IP changes on AWS RDS instances and update a given (NLB) target-group with theses IP addresses.

Most of the python code comes from [1], inspired by [2]

Architecture:

___________________________
| RDS Events subscription |
~~~~~~~~~~~~~~~~~~~~~~~~~~~
            |
            |       _______     __________     ____________________
            +------>| SNS |---->| Lambda |---->| NLB target-group |
                    ~~~~~~~     ~~~~~~~~~~     ~~~~~~~~~~~~~~~~~~~~

When invoked, the lambda function will:

• Lookup IP addresses from given FQDN list
• check target-group registered IPs (target health isn't taken into account)
• add/remove IP from target group so they match the FQDN list.

Prerequisites:

This terraform code doesn't create load-balancer resources nor its components (listener, target-group). You'll have to declare them separately

It basically replaces the function that aws_lb_target_group_attachment resources holds when attaching to static ip addresses.

[1] https://github.com/aws-samples/hostname-as-target-for-elastic-load-balancer

[2] https://aws.amazon.com/blogs/networking-and-content-delivery/hostname-as-target-for-network-load-balancers/

terraform-aws-rds-nlb's Issues

"read replica" event category missing if there is no database replica

Seems like "read replica" event category does not exist if you have no replica database. It might be handy if one could modify the SNS categories through input vars ?

can't find external program python.exe terraform

Hello, I was using this module and it had this error can't find external program python.exe terraform. It was because in package.tf on line 2 was "python.exe" as the program to use. It worked changing it by "py".

It is possible to be changed in the source?

thanks!

private RDS

This doesn't seem to work with a private rds.

question

@saimonn This is not really an issue, but a question...

I'm trying to use this module to allow access from external IP addresses to my internal RDS, but the only way i've succeeded to make it work is without preserve_ip, which is basically opening the RDS to the entire world. I was wondering what is your NLB configuration to allow access to the RDS?

Thank you in advance.