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Installing in your Backstage App

The scaffolder plugin comes in two packages, @backstage/plugin-scaffolder and @backstage/plugin-scaffolder-backend. Each has their own installation steps, outlined below.

The Scaffolder plugin also depends on the Software Catalog. Instructions for how to set that up can be found here.

Installing @backstage/plugin-scaffolder

Note that if you used npx @backstage/create-app, the plugin may already be present

The scaffolder frontend plugin should be installed in your app package, which is created as a part of @backstage/create-app. To install the package, run:

cd packages/app
yarn add @backstage/plugin-scaffolder

Make sure the version of @backstage/plugin-scaffolder matches the version of other @backstage packages. You can update it in packages/app/package.json if it doesn't.

Adding the Plugin to your packages/app

Add the following entry to the head of your packages/app/src/plugins.ts:

export { scaffolderPlugin } from '@backstage/plugin-scaffolder';

Next we need to install the root page that the Scaffolder plugin provides. You can choose any path for the route, but we recommend the following:

import { ScaffolderPage } from '@backstage/plugin-scaffolder';

// Add to the top-level routes, directly within <FlatRoutes>
<Route path="/create" element={<ScaffolderPage />} />;

You may also want to add a link to the template index page to your sidebar:

import CreateComponentIcon from '@material-ui/icons/AddCircleOutline';

// Somewhere within the <Sidebar>
<SidebarItem icon={CreateComponentIcon} to="create" text="Create..." />;

This is all that is needed for the frontend part of the Scaffolder plugin to work!

Installing @backstage/plugin-scaffolder-backend

Note that if you used npx @backstage/create-app, the plugin may already be present

The scaffolder backend should be installed in your backend package, which is created as a part of @backstage/create-app. To install the package, run:

cd packages/backend
yarn add @backstage/plugin-scaffolder-backend

Make sure the version of @backstage/plugin-scaffolder-backend matches the version of other @backstage packages. You can update it in packages/backend/package.json if it doesn't.

Adding the Plugin to your packages/backend

You'll need to add the plugin to the backend's router. You can do this by creating a file called packages/backend/src/plugins/scaffolder.ts with the following contents to get you up and running quickly.

import {
  CookieCutter,
  createRouter,
  Preparers,
  Publishers,
  CreateReactAppTemplater,
  Templaters,
} from '@backstage/plugin-scaffolder-backend';
import { SingleHostDiscovery } from '@backstage/backend-common';
import type { PluginEnvironment } from '../types';
import Docker from 'dockerode';
import { CatalogClient } from '@backstage/catalog-client';

export default async function createPlugin({
  logger,
  config,
  database,
}: PluginEnvironment) {
  const cookiecutterTemplater = new CookieCutter();
  const craTemplater = new CreateReactAppTemplater();
  const templaters = new Templaters();

  templaters.register('cookiecutter', cookiecutterTemplater);
  templaters.register('cra', craTemplater);

  const preparers = await Preparers.fromConfig(config, { logger });
  const publishers = await Publishers.fromConfig(config, { logger });

  const dockerClient = new Docker();

  const discovery = SingleHostDiscovery.fromConfig(config);
  const catalogClient = new CatalogClient({ discoveryApi: discovery });

  return await createRouter({
    preparers,
    templaters,
    publishers,
    logger,
    config,
    dockerClient,
    database,
    catalogClient,
  });
}

Once the scaffolder.ts router setup file is in place, add the router to packages/backend/src/index.ts:

import scaffolder from './plugins/scaffolder';

const scaffolderEnv = useHotMemoize(module, () => createEnv('scaffolder'));

const service = createServiceBuilder(module)
  .loadConfig(configReader)
  /** several different routers */
  .addRouter('/scaffolder', await scaffolder(scaffolderEnv));

Adding Templates

At this point the scaffolder backend is installed in your backend package, but you will not have any templates available to use. These need to be added to the software catalog, as they are represented as entities of kind Template. You can find out more about adding templates here.

To get up and running and try out some templates quickly, you can add some of our example templates through static configuration. Add the following to the catalog.locations section in your app-config.yaml:

catalog:
  locations:
    # Backstage Example Templates
    - type: url
      target: https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend/sample-templates/react-ssr-template/template.yaml
    - type: url
      target: https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend/sample-templates/springboot-grpc-template/template.yaml
    - type: url
      target: https://github.com/backstage/backstage/blob/master/plugins/scaffolder-backend/sample-templates/create-react-app/template.yaml
    - type: url
      target: https://github.com/spotify/cookiecutter-golang/blob/master/template.yaml

Runtime Dependencies / Configuration

For the scaffolder backend plugin to function, it needs a GitHub access token, and access to a running Docker daemon. You can create a GitHub access token here, select repo scope only. Full docs on creating private GitHub access tokens is available here. Note that the need for private GitHub access tokens will be replaced with GitHub Apps integration further down the line by using the existing integrations config.

Note: Some of this configuration may already be set up as part of your app-config.yaml. We're moving away from the duplicated config for authentication in the scaffolder section and using integrations instead.

GitHub

The GitHub access token is retrieved from environment variables via the config. The config file needs to specify what environment variable the token is retrieved from. Your config should have the following objects.

You can configure who can see the new repositories that the scaffolder creates by specifying visibility option. Valid options are public, private and internal. The internal option is for GitHub Enterprise clients, which means public within the enterprise.

integrations:
  github:
    - host: github.com
      token:
        $env: GITHUB_TOKEN

scaffolder:
  github:
    visibility: public # or 'internal' or 'private'

GitLab

For GitLab, we currently support the configuration of the GitLab publisher and allows to configure the private access token and the base URL of a GitLab instance:

integrations:
  gitlab:
    - host: gitlab.com
      token:
        $env: GITLAB_TOKEN

Azure DevOps

For Azure DevOps we support both the preparer and publisher stage with the configuration of a private access token (PAT). For the publisher it's also required to define the base URL for the client to connect to the service. This will hopefully support on-prem installations as well but that has not been verified.

integrations:
  azure:
    - host: dev.azure.com
      token:
        $env: AZURE_TOKEN

Running the Backend

Finally, make sure you have a local Docker daemon running, and start up the backend with the new configuration:

cd packages/backend
GITHUB_TOKEN=<token> yarn start

If you've also set up the frontend plugin, so you should be ready to go browse the templates at localhost:3000/create now!