Serve — Docker

Package a Rank HTTP app into a container image using rank serve.

Source

examples/serve-docker/main.rank

use std::HTTP

HealthRoute = HTTP::Route {
  method: `GET`,
  path: `/health`
}

Routes = HealthRoute

pub config = {
  defaultResponseFormat: `json`
}

pub main = || -> HTTP::Response {
  return {
    status: 200,
    body: {
      ok: true,
      service: `serve-docker-example`
    }
  }
}

examples/serve-docker/rank.toml

manifestVersion = 1

[package]
name = "serve-docker-example"
version = "0.1.0"
source = "."

examples/serve-docker/Dockerfile

FROM node:22-slim

WORKDIR /app

RUN npm install -g @rank-lang/cli

COPY rank.toml main.rank ./

RUN rank sync .

EXPOSE 3000

CMD ["rank", "serve", ".", "--host", "0.0.0.0", "--port", "3000"]

Build and run

docker build -t rank-serve-example .
docker run --rm -p 3000:3000 rank-serve-example

curl http://127.0.0.1:3000/health

{
  "ok": true,
  "service": "serve-docker-example"
}

For local parity without Docker:

rank serve . --host 127.0.0.1 --port 3000

Key concepts

• rank sync . — runs during the Docker build to cache all registry dependencies. The container starts without making outbound package requests.
• --host 0.0.0.0 — binds to all interfaces so traffic forwarded by Docker reaches the server. In local development use 127.0.0.1 (the default).
• pub config — sets defaultResponseFormat: \json`so all route responses are serialized as JSON without having to specifyformat` on each one.
• /.well-known/rank/ready — built-in readiness endpoint managed by the server runtime, not part of the application route table. Use it for Docker health checks or load-balancer probes.