A trivial Terraform example for WireGuard peering

This is potato-Terraform sufficient to create an RDS database, and connect it to a Fly.io 6PN network. It needs:

• An AWS account (strong recommend: aws-vault)

• A password for a newly created RDS database

• A WireGuard configuration generated from flyctl wireguard create, in wg0.conf.

• An SSH key pair (you'll need to edit the Terraform, replacing YOUR_KEY_HERE).

It will create:

• A new VPC, numbered 172.16.0.0/16

• An EC2 instance, to which SSH is allowed from the world (see below).

• An RDS database called "appdb" with the specified password, and a security group rule allowing the EC2 instance to talk to it.

It uses Terraform's remote-exec to provision the EC2 instance:

• Installing WireGuard

• Setting up the WireGuard configuration

• Installing PgBouncer

• Configuring PgBouncer to talk to our RDS instance.

After running, you should have a WireGuard peer in your 6PN DNS, by whichever name you gave the peer, to which you can connect Postgres on 5432/tcp.

Important Note

Part of the point of deploying like this is not having management dependencies like SSH lying around, but an even bigger point of why I work at Fly.io is not having to be good at Terraform, so I don't have a standalone Terraform that "temporarily" allows SSH. If it were me, I'd just go in afterwards and kill the SSH rule with the AWS CLI. Maybe you'd create an AMI instead; there's lots of ways to do this.