Boiler plate: your own CuOS Init App

A starting point for the Own CuOS Init App level — you implement your own update mechanism or way of deployment, instead of letting CuOS IaC do it.

The CuOS Init App is the one container CuOS starts on a finished system, and from which everything else is started. CuOS names it in init_image.

File	What it is
Dockerfile	Alpine base, with the dev.cuos.app_command label naming the mounts a CuOS Init App needs — the docker socket, the registry credentials, /system.json, the API socket and the custom CA certificates.
entrypoint.sh	Where your application starts. Reports readiness, then keeps running.
cuos_lib.sh	Shell wrappers around the CuOS API socket: cuos_ready, cuos_update.
api/post_update	Optional hook CuOS runs in this container after a successful update. Delete it if you have nothing to do there.

Use it

1. Fork or copy this repository.
2. Put your application into entrypoint.sh and the Dockerfile.
3. Publish the image, then point init_image at it:

{
  "#include": ["cuos-release/release.json"],
  "hostname": "my-system",
  "init_image": "ghcr.io/my-org/my-init-app",
  "init_image_version": "1.0.0",
  "init_image_digest": "sha256:..."
}

Naming init_image yourself replaces CuOS IaC, which release.json otherwise pins there.

4. Build the system with cuos-release.

Before you ship

Everything a remote system sends you must be protected by signatures. CuOS IaC uses git commit signing and docker digest checks; an Init App that updates the system has to bring its own equivalent. An update path that trusts whatever it downloads is a remote code execution path.

The commented block in the Dockerfile lists the hardening options worth turning on — memory limit, read-only root, tmpfs mounts.

Next

• Your CuOS Init App — the label, the startup parameters, the update hook, the rollback rules
• CuOS API — what the socket accepts

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License

MIT-0 — see LICENSE.txt. MIT without the attribution clause: copy this, change it, ship it, and you owe nothing — no notice to carry, no credit to give.

That is deliberate. This repository exists to be taken. CuOS itself is Apache-2.0; only the boiler plates and the example are MIT-0.