Deploying Deno with Docker

Description of video Jump to heading#

See how to deploy Deno applications with Docker to a compatible cloud environment.

Resources Jump to heading#

• https://github.com/denoland/deno_docker
• https://fly.io/

Transcript and code Jump to heading#

Deno has made a lot of things seem easy: linting, formatting, interoperability with the Node ecosystem, testing, TypeScript, but how about deployment? How easy is it to get Deno running in production? Pretty easy!

Let’s start with a look at our app. It’s an app that provides us with some information about trees. On the homepage we get some text At the trees route, we get some JSON At the dynamic route based on the tree’s id, we get information about that single tree.

import { Hono } from "jsr:@hono/hono";

const app = new Hono();

interface Tree {
  id: string;
  species: string;
  age: number;
  location: string;
}

const oak: Tree = {
  id: "1",
  species: "oak",
  age: 3,
  location: "Jim's Park",
};

const maple: Tree = {
  id: "2",
  species: "maple",
  age: 5,
  location: "Betty's Garden",
};

const trees: Tree[] = [oak, maple];

app.get("/", (c) => {
  return c.text("🌲 🌳 The Trees Welcome You! 🌲 🌳");
});

app.get("/trees", (c) => {
  return c.json(trees);
});

app.get("/trees/:id", (c) => {
  const id = c.req.param("id");
  const tree = trees.find((tree) => tree.id === id);
  if (!tree) return c.json({ message: "That tree isn't here!" }, 404);
  return c.json(tree);
});

Deno.serve(app.fetch);

Run Locally with Docker Jump to heading#

Make sure that Docker is installed on your machine. In your terminal or command prompt, you can run docker and if you get a big list of commands, you have it. If not, head over to https://www.docker.com/ and download it based on your operating system.

Test run docker: Jump to heading#

docker

Then run the command to get running on localhost:8000 with Docker

docker run -it -p 8000:8000 -v $PWD:/my-deno-project denoland/deno:2.0.2 run
--allow-net /my-deno-project/main.ts

Visit the app running at localhost:8000

It’s also possible to run this with a docker config file.

FROM
denoland/deno:2.0.2

# The port that your application listens to.

EXPOSE 8000

WORKDIR /app

# Prefer not to run as root.
USER deno

# These steps will be re-run upon each file change in your working directory:
COPY . .

# Compile the main app so that it doesn't need to be compiled each startup/entry.
RUN deno cache main.ts

# Warmup caches
RUN timeout 10s deno -A main.ts || [ $? -eq 124 ] || exit 1

CMD ["run", "--allow-net", "main.ts"]

Then build it

docker build -t my-deno-project .

From there, you can deploy the app to your hosting provider of choice. I’m going to use fly.io today.

Deploy to fly.io Jump to heading#

If you haven’t worked with fly before, it’s a cloud platform that allows you to deploy and run fullstack apps. They run in multiple regions throughout the world which makes them a pretty nice option. https://fly.io/

Install Fly Jump to heading#

Install with curl

curl -L https://fly.io/install.sh | sh

Log in with Fly via CLI Jump to heading#

fly auth login

This will open the browser for you to log into your account (or create one if you haven’t already). Then we’ll launch the app with fly using:

flyctl launch

This will generate a fly.toml file for the app, and you can choose different settings if you’d like to. And more importantly it will launch it! We’ll just wait for the process to complete, and we should be able to view our app running at that location.

So with Deno, we can use Docker to containerize the app and with Fly we can get the app hosted in production in just a few minutes.