Deploy modes

Hostrig supports exactly three deploy paths. The builder picks one based on your deployment input.

1. Prebuilt image

Provide a registry image reference (e.g. nginx:alpine, ghcr.io/org/app:tag). Hostrig pulls the image and runs it with bound env injected.

Use when: you already publish container images from CI.

2. Dockerfile

If the source tree contains a Dockerfile, Hostrig runs docker build (via BuildKit) and tags the result as deplow/<slug>:<deploymentId>.

Use when: you have an existing container build definition.

3. Railpack (default for source)

If there is no Dockerfile, Hostrig invokes Railpack:

railpack build --name deplow/<slug>:<deploymentId> <source>

Use when: you want zero-config builds from source — the primary happy path.

Build selection logic

if image provided     → pull & run
else if Dockerfile    → docker build → run
else                  → railpack build → run

Not supported

• Docker Compose as a deploy target
• Nixpacks / Paketo / Heroku buildpacks
• Remote builders or multi-host orchestration

Compose-related code paths may exist as stubs but are intentionally rejected.