Heroku Buildpack for create-react-app

Deploy React.js web apps generated with create-react-app.

Automates deployment with the built-in tooling and serves it up via Nginx.

Requires

• Heroku
  • command-line tools (CLI)
  • a free account
• git
• Node.js
• create-react-app
  • npm install -g create-react-app

Usage

Generate a React app

create-react-app my-app
cd my-app

Make it a git repo

git init

At this point, this new repo is local, only on your computer. Eventually, you may want to push to Github.

Create the Heroku app

heroku create my-app-name --buildpack https://github.com/mars/create-react-app-buildpack.git

✏️ Replace my-app-name with a name for your unique app.

This command:

• sets the app name & its URL https://my-app-name.herokuapp.com
• sets the buildpack to deploy a create-react-app app
• configures the heroku remote in the local git repo, so git push heroku master will push to this new Heroku app.

Commit & deploy ♻️

git add .
git commit -m "react-create-app on Heroku"
git push heroku master

Visit the app's public URL in your browser

heroku open

Visit the Heroku Dashboard for the app

Find the app on your dashboard.

Continue Development

Work with your app locally using npm start. See: create-react-app docs

Then, commit & deploy ♻️

Push to Github

Eventually, to share, collaborate, or simply back-up your code, create an empty repo at Github, and then follow the instructions shown on the repo to push an existing repository from the command line.

Customization

Web server

The web server may be configured via the static buildpack.

The default static.json, if it does not exist in the repo, is:

{ "root": "build/" }

Routing clean URLs

By default, React Router (not included) uses hash-based URLs like https://example.com/index.html#/users/me/edit. This is nice & easy when getting started with local development, but for a public app you probably want real URLs like https://example.com/users/me/edit.

Create a static.json file to configure the web server for clean browserHistory URLs with React Router:

{
  "root": "build/",
  "clean_urls": false,
  "routes": {
    "/**": "index.html"
  }
}

Environment variables

REACT_APP_* and NODE_* environment variables are supported on Heroku during the compile phase, when npm run build is executed to generate the JavaScript bundle.

Set config vars on a Heroku app like this:

heroku config:set REACT_APP_HELLO='I love sushi!'

Add-on config vars

To use the config vars directly from an add-on, create it with a custom REACT_APP_ prefix.

Example with the fixie add-on:

heroku addons:create fixie --as REACT_APP_FIXIE

See: Creating an add-on

Stateless builds

Environment variables may be different between various instances of an app, such as dev, staging, & production. This buildpack follows Heroku's stateless app architecture by bundling the JavaScript with these values everytime a dyno starts-up.

If bundling the JavaScript takes longer than the boot timeout limit (currently 60-seconds), then the app will fail to start-up.

Here are a few options to work around this limitation:

• limit use of environment vars to values that do not change between instances of the app
• heroku config:set REACT_APP_STATEFUL_BUILD=true will switch bundling the JavaScript to the build phase, where it has a time limit of 30-minutes, but updating environment variables will require redeployment, potentially breaking things like Pipeline promotions
• contact Heroku support to have the boot timeout for the app lifted up to 120-seconds, but this will cause slower recovery from app crashes

Version compatibility

We'll keep branches to maintain compatibility as create-react-app evolves. These will only be useful for projects that have been ejected and therefore stagnate with the tooling of a specific version.

Currently, using branch cra-0.2.x will ensure that your deployment continues to work with 0.2.x versions of create-react-app.

heroku create -b https://github.com/mars/create-react-app-buildpack.git#cra-0.2.x

Usually, using master as directed in the main instructions will be appropriate to automatically keep up with the newest create-react-app.

Architecture 🏙

This buildpack composes three buildpacks (specified in .buildpacks) to support no-configuration deployment on Heroku:

1. heroku/nodejs buildpack

• complete Node.js enviroment to support the webpack build
• node_modules cached between deployments

2. mars/create-react-app-inner-buildpack

• generates the default static.json

3. heroku/static buildpack

• Nginx web server
• handy static website & SPA (single-page app) customization options

4. This buildpack builds the JavaScript bundle in one of two ways:
5. when config var REACT_APP_STATEFUL_BUILD is set to true, then npm run build is executed during compile once for the deploy
6. otherwise, npm run build is executed in the runtime each time a dyno starts-up

General-purpose SPA deployment

Some kind feedback pointed out that this buildpack is not necessarily specific to create-react-app.

This buildpack can deploy any SPA [single-page app] as long as it meets the following requirements:

• npm run build performs the transpile/bundling
• the file build/index.html or the root specified in static.json exists at runtime.