Show HN: Forja – Remote Docker Builders on AWS

Hello HN. I got sick of docker builds on my mac taking forever, so I built forja.

Forja is an ephemeral Docker builder that runs entirely in your own AWS account. It spins up real EC2 instances for each build (`c7a` for AMD64, `c7g` for ARM), builds your image with BuildKit, pushes cache layers to S3, and then tears the machine down.

Here’s how it works: - The CLI asks AWS for a fresh EC2 instance with a pre-baked AMI (boots in ~5 seconds, ready to build in ~30). - It sets up mutual TLS on the fly: for each build it creates a short-lived CA, issues client/server certs, drops them in S3, and both sides mutually auth before any data moves. - BuildKit runs on the remote box, pulls/pushes cache layers to S3 so future builds stay fast even though every machine is ephemeral. - When the build finishes or fails—or even if you Ctrl+C—the instance self-terminates and the certs disappear with it.

Let me know what you think!

Cheers, Benji