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Deploy a React app with create‑react‑app

​​ Before you start

All of the tutorials assume you have already completed the Get started guide, which gets you set up with a Cloudflare Workers account, and the Workers CLI tool, Wrangler.

​​ Overview

In this tutorial, you will use Wrangler and Cloudflare Workers to deploy and serve a static site. With the rise of architectures like JAMStack, static sites have become a simple, streamlined way to combine highly available static assets with performant back-end code, especially when deployed in a serverless model. With Workers, your application will be distributed to over 200+ locations around the world and served directly from Cloudflare’s CDN at the server closest to your users.

If you just want to review the code used in this tutorial, the final version of the codebase is available on GitHub. You can take that code, customize it, and deploy it for use in your own projects.

​​ Prerequisites

You will be using create-react-app to create the example project for this tutorial. No experience with React is needed. You can utilize what you learn in this tutorial and apply it to other frameworks, such as Vue or Angular, and even static site frameworks like Gatsby and Hugo.

​​ Create a static site

In this tutorial, you will use create-react-app to build a simple static application. Create a new project directly by using npx:

Create a new React application
$ npx create-react-app my-static-site

create-react-app will create a new project and include all the relevant dependencies needed to build the project.

​​ Generate a project

In the command line, navigate to your newly created React project and use wrangler init --site to generate a Workers Sites configuration for your project:

Initialize a new Wrangler project
$ cd my-static-site
$ wrangler init --site

The init --site command will provide the scaffolding necessary to deploy your React application. For the majority of static sites, you should not need to change the Workers script. By default, the script will look at an incoming request, and will serve a corresponding asset from Workers KV based on that route.

For example, if you deploy a static site at mystaticsite.com, requesting mystaticsite.com/about.html will look for a file in KV called about.html and serve it back to the client. In addition, if the asset being returned from KV is cacheable, it will automatically be cached with Cloudflare’s CDN, making subsequent requests even faster.

To serve a single page application, update workers-site/index.js with the following code so that all HTML requests are pointed at your root index.html file.

import { getAssetFromKV, serveSinglePageApp } from '@cloudflare/kv-asset-handler';
async function handleEvent(event) {
...
const asset = await getAssetFromKV(event, { mapRequestToAsset: serveSinglePageApp });
}

​​ Configure and publish

To prepare your application for deployment, open the newly created wrangler.toml file, which represents the configuration for your Workers application. Using the Configuring your project section in Get started as a guide, populate wrangler.toml with your account ID, which will allow you to deploy your React application to your Cloudflare account.

The bucket key in your wrangler.toml file indicates the build folder that Sites will deploy to Workers. While many front-end application and static site generators use the folder public, create-react-app uses the folder build. Change the bucket key in wrangler.toml to build:

wrangler.toml
# ... previous wrangler config
[site]
bucket = "./build"
entry-point = "workers-site"

With a configured wrangler.toml file, it is time to build your project and publish it to Workers. Run npm run build to tell create-react-app to build your site and wrangler publish to deploy it to Workers:

Build and publish your application
$ npm run build
$ wrangler publish

After deploying your project, open your browser to review your static site.

After deploying your browser, you will be able to review your successfully published static site

​​ How it works

The Workers Site feature is designed to work with as little configuration as possible. Since the process for deploying static sites is fairly consistent, regardless of framework or language, you should not need to spend a lot of time configuring your project or writing any additional code to serve your site on Workers.

If you are interested in how a Workers Site operates, this section will briefly document how the underlying script works and what it does each time a user makes a request to your site.

Like all Workers scripts, the static site feature begins by listening for incoming fetch events to your application — these are incoming requests from a client, such as a browser or a phone:

index.js
addEventListener("fetch", event => {
event.respondWith(handleRequest(event.request))
})

When the script receives an incoming Request, it looks at the pathname, such as /workers, and looks up an associated file uploaded to Workers KV. If that file is found, a new Response is generated, with a matching MIME type in the Content-Type header of the response. For example, if the path /workers.jpg is requested, a new response is returned with the header Content-type: image/jpeg.

After fetching assets from Workers KV, the static site template will cache them in Cloudflare’s CDN. When subsequent users request /index.html, Cloudflare’s CDN will transparently serve a cached version.

In this tutorial, you built and published a static site to Workers. If you would like to see the full source code for this application, the final version of the codebase is available in a GitHub repository.

If you want to get started building your own projects, review the existing list of Quickstart templates.