This section describes how to get set up for doing development on the Backstage repository.
Cloning the Repository
Ok. So you're gonna want some code right? Go ahead and fork the repository into your own GitHub account and clone that code to your local machine or you can grab the one for the origin like so:
git clone firstname.lastname@example.org:backstage/backstage --depth 1
If you cloned a fork, you can add the upstream dependency like so:
git remote add upstream email@example.com:backstage/backstage git pull upstream master
After you have cloned the Backstage repository, you should run the following commands once to set things up for development:
$ yarn install # fetch dependency packages - may take a while $ yarn tsc # does a first run of type generation and checks
Serving the Example App
Open a terminal window and start the web app by using the following command from the project root. Make sure you have run the above mentioned commands first.
$ yarn dev
This is going to start two things, the frontend (:3000) and the backend (:7000).
This should open a local instance of Backstage in your browser, otherwise open one of the URLs printed in the terminal.
By default, Backstage will start on port 3000, however you can override this by
setting an environment variable
PORT on your local machine. e.g.
export PORT=8080 then running
yarn start. Or
PORT=8080 yarn start.
Once successfully started, you should see the following message in your terminal window:
$ concurrently "yarn start" "yarn start-backend" $ yarn workspace example-app start $ yarn workspace example-backend start $ backstage-cli app:serve $ backstage-cli backend:dev  Loaded config from app-config.yaml  Build succeeded  ℹ ｢wds｣: Project is running at http://localhost:3000/  ℹ ｢wds｣: webpack output is served from /  ℹ ｢wds｣: Content not from webpack is served from $BACKSTAGE_DIR/packages/app/public  ℹ ｢wds｣: 404s will fallback to /index.html  ℹ ｢wdm｣: wait until bundle finished: /  2021-02-12T20:58:17.614Z backstage info Loaded config from app-config.yaml
You'll see how you get both logs for the frontend
serves the react app () and the backend ();
Visit http://localhost:3000 and you should see the bleeding edge of Backstage ready for contributions!
The Backstage development environment does not require any specific editor, but
it is intended to be used with one that has built-in linting and type-checking.
The development server does not include any checks by default, but they can be
enabled using the
--check flag. Note that using the flag may consume more
system resources and slow things down.
There are many commands to be found in the root package.json, here are some useful ones:
yarn start # Start serving the example app, use --check to include type checks and linting yarn storybook # Start local storybook, useful for working on components in @backstage/core yarn workspace @backstage/plugin-welcome start # Serve welcome plugin only, also supports --check yarn tsc # Run typecheck, use --watch for watch mode yarn tsc:full # Run full type checking, for example without skipLibCheck, use in CI yarn build # Build published versions of packages, depends on tsc yarn lint # lint packages that have changed since later commit on origin/master yarn lint:all # lint all packages yarn lint:type-deps # verify that @types/* dependencies are placed correctly in packages yarn test # test packages that have changed since later commit on origin/master yarn test:all # test all packages yarn clean # Remove all output folders and @backstage/cli cache yarn diff # Make sure all plugins are up to date with the latest plugin template yarn create-plugin # Create a new plugin
See package.json for other yarn commands/options.
Backstage allows you to specify the configuration used while running the
application on your computer. Local configuration is read from
app-config.local.yaml. This file is ignored by Git, which means that you can
safely use it to reference secrets like GitHub tokens without worrying about
these secrets, inadvertently ending up in the Git repository. You do not need to
copy everything from the default config to the local config.
app-config.local.yaml will be merged with
app-config.yaml and overwrite the
default app configs.
NOTE: If you want to add your own configuration values to access in the frontend you also need to mark those values as visible using configuration schema, either in the app or in your own plugin. For more information, see Defining Configuration.
You can learn more about the local configuration in Static Configuration in Backstage section.