Packer

Packer builds identical machine images for AWS, Azure, GCP, and VMware from the same configuration, defined in code. Packer does that. Instead of manually configuring a server and hoping you remember every step, you write a template that says "start with Ubuntu, install these packages, configure these settings" and Packer builds the image automatically.

The entire tool is free under the BSL license (business source license, free for most use cases, restricted for competing managed services). No paid features, no cloud tier from HashiCorp specifically for Packer. You download the binary and run it.

There's nothing to host; it's a CLI tool that runs on your machine and talks to cloud APIs. Install it, write a template in HCL or JSON, run `packer build`. It creates the image in your cloud provider and exits. Ops burden is trivial. Solo developers: useful if you're automating infrastructure. Otherwise, a manual AMI snapshot works fine. Small teams: Packer templates in version control mean everyone builds the same image. Growing teams: this is where it shines: golden images across multiple clouds, baked into your CI/CD.

The catch: Packer solves one problem well but it's only the image layer. You still need Terraform or similar to deploy those images. And the BSL license change in 2023 upset the open source community; if you're philosophically opposed, look at alternatives.