Docker and systemd

Use the devbox image to get Docker, Compose, and Buildx already installed. Docker starts when the Sailbox boots.

sail box devbox up docker-demo
sail box shell <id>

import sail

app = sail.App.find(name="my-app", mint_if_missing=True)
sb = sail.Sailbox.create(
    app=app, name="docker-demo", image=sail.Image.devbox("amd64")
)
print(sb.run("docker version").stdout)

import { App, Image, Sailbox } from "@sailresearch/sdk";

const app = await App.find("my-app", { mintIfMissing: true });
const sb = await Sailbox.create({
  app,
  name: "docker-demo",
  image: Image.devbox("amd64"),
});
console.log((await sb.run("docker version")).stdout);

Run a container

Inside the Sailbox:

docker run --rm hello-world
docker run -d --name web --restart unless-stopped -p 8080:80 nginx:alpine

From your machine, expose the published port:

sail box expose <id> 8080
sail box address <id> 8080

Publishing a Docker port makes it available inside the Sailbox. Exposing it through Sail gives it a public endpoint. See Networking.

Use Compose

Copy your project into the Sailbox, then start it there:

sail box cp --recursive ./app <id>:/root/app
sail box exec <id> -- sh -lc 'cd /root/app && docker compose up -d'

To build the whole Sailbox from a Dockerfile or Compose project instead, see Custom images.

systemd

Devbox images already run systemd. For a custom image, call with_systemd and enable your service during the image build.

Define a service

Create worker.service next to your application:

worker.service

[Unit]
Description=Application worker
After=network-online.target

[Service]
WorkingDirectory=/opt/app
ExecStart=/usr/bin/python3 /opt/app/worker.py
Restart=always

[Install]
WantedBy=multi-user.target

Build the image

import sail

image = (
    sail.Image.debian_amd64
    .with_systemd()
    .add_local_dir("./app", "/opt/app")
    .add_local_file("./worker.service", "/etc/systemd/system/worker.service")
    .run_commands("systemctl enable worker.service")
)
app = sail.App.find(name="my-app", mint_if_missing=True)
sb = sail.Sailbox.create(app=app, name="worker", image=image)

import { App, Image, Sailbox } from "@sailresearch/sdk";

const image = Image.debian("amd64")
  .withSystemd()
  .addLocalDir("./app", "/opt/app")
  .addLocalFile("./worker.service", "/etc/systemd/system/worker.service")
  .runCommand("systemctl enable worker.service");
const app = await App.find("my-app", { mintIfMissing: true });
const sb = await Sailbox.create({ app, name: "worker", image });

The service starts when the Sailbox boots. It may still be starting when create returns; check the application’s readiness before sending work.

Inspect and restart

Inside the Sailbox:

systemctl status worker
journalctl -u worker -f
systemctl restart worker

with_systemd works with the Debian base, registry images, and Dockerfile images. Compose images cannot use it. See the image reference for timers and reboot behavior.

Getting started

Inference

Sailboxes

Guides

Security & compliance

Run a container

Use Compose

systemd

Define a service

Build the image

Inspect and restart

​Run a container

​Use Compose

​systemd

​Define a service

​Build the image

​Inspect and restart

Run a container

Use Compose

systemd

Define a service

Build the image

Inspect and restart