How to talk to the public internet from AWS ECS

At $WORK I’ve been recently thrown head-first into designing, building and improving an AWS setup and this reality with ECS networking really tripped me up.

To get going quickly, we setup Fargate with a Public IP address. That allowed us to verify that our containerised backend was being built, pushed and run correctly in ECS and that we were able to CURL it over the internet - success!

We knew this wasn’t the end goal, so I got to work setting up an ALB, having