DEPRECATED

This project repo is no longer being maintained. For more information on code-gov repos, go to GSA/code-gov.

This project was bootstrapped with Create React App.

Below you will find some information on how to perform common tasks.
You can find the most recent version of this guide here.

Deployment

npm run build creates a build directory with a production build of your app. Set up your favourite HTTP server so that a visitor to your site is served index.html, and requests to static paths like /static/js/main.<hash>.js are served with the contents of the /static/js/main.<hash>.js file. For example, Python contains a built-in HTTP server that can serve static files:

cd build
python -m SimpleHTTPServer 9000

If you're using Node and Express as a server, it might look like this:

const express = require('express');
const path = require('path');
const app = express();

app.use(express.static('./build'));

app.get('/', function (req, res) {
  res.sendFile(path.join(__dirname, './build', 'index.html'));
});

app.listen(9000);

Create React App is not opinionated about your choice of web server. Any static file server will do. The build folder with static assets is the only output produced by Create React App.

However this is not quite enough if you use client-side routing. Read the next section if you want to support URLs like /todos/42 in your single-page app.

Serving Apps with Client-Side Routing

If you use routers that use the HTML5 pushState history API under the hood (for example, React Router with browserHistory), many static file servers will fail. For example, if you used React Router with a route for /todos/42, the development server will respond to localhost:3000/todos/42 properly, but an Express serving a production build as above will not.

This is because when there is a fresh page load for a /todos/42, the server looks for the file build/todos/42 and does not find it. The server needs to be configured to respond to a request to /todos/42 by serving index.html. For example, we can amend our Express example above to serve index.html for any unknown paths:

 app.use(express.static('./build'));

-app.get('/', function (req, res) {
+app.get('/*', function (req, res) {
   res.sendFile(path.join(__dirname, './build', 'index.html'));
 });

Now requests to /todos/42 will be handled correctly both in development and in production.

Building for Relative Paths

By default, Create React App produces a build assuming your app is hosted at the server root.
To override this, specify the homepage in your package.json, for example:

  "homepage": "http://mywebsite.com/relativepath",

This will let Create React App correctly infer the root path to use in the generated HTML file.

GitHub Pages

Note: this feature is available with react-scripts@0.2.0 and higher.

Step 1: Add homepage to package.json

The step below is important!
If you skip it, your app will not deploy correctly.

Open your package.json and add a homepage field:

  "homepage": "https://myusername.github.io/my-app",

Create React App uses the homepage field to determine the root URL in the built HTML file.

Step 2: Install gh-pages and add deploy to scripts in package.json

Now, whenever you run npm run build, you will see a cheat sheet with instructions on how to deploy to GitHub Pages.

To publish it at https://myusername.github.io/my-app, run:

npm install --save-dev gh-pages

Add the following script in your package.json:

  // ...
  "scripts": {
    // ...
    "deploy": "npm run build&&gh-pages -d build"
  }

(Note: the lack of whitespace is intentional.)

Step 3: Deploy the site by running npm run deploy

Then run:

npm run deploy

Step 4: Ensure your project's settings use gh-pages

Finally, make sure GitHub Pages option in your GitHub project settings is set to use the gh-pages branch:

Step 5: Optionally, configure the domain

You can configure a custom domain with GitHub Pages by adding a CNAME file to the public/ folder.

Notes on client-side routing

GitHub Pages doesn't support routers that use the HTML5 pushState history API under the hood (for example, React Router using browserHistory). This is because when there is a fresh page load for a url like http://user.github.io/todomvc/todos/42, where /todos/42 is a frontend route, the GitHub Pages server returns 404 because it knows nothing of /todos/42. If you want to add a router to a project hosted on GitHub Pages, here are a couple of solutions:

• You could switch from using HTML5 history API to routing with hashes. If you use React Router, you can switch to hashHistory for this effect, but the URL will be longer and more verbose (for example, http://user.github.io/todomvc/#/todos/42?_k=yknaj). Read more about different history implementations in React Router.
• Alternatively, you can use a trick to teach GitHub Pages to handle 404 by redirecting to your index.html page with a special redirect parameter. You would need to add a 404.html file with the redirection code to the build folder before deploying your project, and you’ll need to add code handling the redirect parameter to index.html. You can find a detailed explanation of this technique in this guide.

Heroku

Use the Heroku Buildpack for Create React App.
You can find instructions in Deploying React with Zero Configuration.

S3 and CloudFront

See this blog post on how to deploy your React app to Amazon Web Services S3 and CloudFront.

Troubleshooting

It is reported that npm run build can fail on machines with no swap space, which is common in cloud environments. If the symptoms are matching, consider adding some swap space to the machine you’re building on, or build the project locally.