---
title: Containerize a Deno application
linkTitle: Containerize your app
weight: 10
keywords: deno, containerize, initialize
description: Learn how to containerize a Deno application.
aliases:
  - /language/deno/containerize/
---

## Prerequisites

* You have a [Git client](https://git-scm.com/downloads). The examples in this section use a command-line based Git client, but you can use any client.

## Overview

For a long time, Node.js has been the go-to runtime for server-side JavaScript applications. However, recent years have introduced new alternative runtimes, including [Deno](https://deno.land/). Like Node.js, Deno is a JavaScript and TypeScript runtime, but it takes a fresh approach with modern security features, a built-in standard library, and native support for TypeScript.

Why develop Deno applications with Docker? Having a choice of runtimes is exciting, but managing multiple runtimes and their dependencies consistently across environments can be tricky. This is where Docker proves invaluable. Using containers to create and destroy environments on demand simplifies runtime management and ensures consistency. Additionally, as Deno continues to grow and evolve, Docker helps establish a reliable and reproducible development environment, minimizing setup challenges and streamlining the workflow.

## Get the sample application

Clone the sample application to use with this guide. Open a terminal, change
directory to a directory that you want to work in, and run the following
command to clone the repository:

```console
$ git clone https://github.com/dockersamples/docker-deno.git && cd docker-deno
```

You should now have the following contents in your `deno-docker` directory.

```text
├── deno-docker/
│ ├── compose.yml
│ ├── Dockerfile
│ ├── LICENSE
│ ├── server.ts
│ └── README.md
```

## Understand the sample application

The sample application is a simple Deno application that uses the Oak framework to create a simple API that returns a JSON response. The application listens on port 8000 and returns a message `{"Status" : "OK"}` when you access the application in a browser.

```typescript
// server.ts
import { Application, Router } from "https://deno.land/x/oak@v12.0.0/mod.ts";

const app = new Application();
const router = new Router();

// Define a route that returns JSON
router.get("/", (context) => {
  context.response.body = { Status: "OK" };
  context.response.type = "application/json";
});

app.use(router.routes());
app.use(router.allowedMethods());

console.log("Server running on http://localhost:8000");