backstage/plugins/scaffolder/README.md

Scaffolder Frontend

This is the React frontend for the default Backstage software templates. This package supplies interfaces related to showing available templates in the Backstage catalog and the workflow to create software using those templates.

Installation

This @backstage/plugin-scaffolder package comes installed by default in any Backstage application created with npx @backstage/create-app, so installation is not usually required.

To check if you already have the package, look under packages/app/package.json, in the dependencies block, for @backstage/plugin-scaffolder. The instructions below walk through restoring the plugin, if you previously removed it.

# From your Backstage root directory
yarn --cwd packages/app add @backstage/plugin-scaffolder

Once installed, the plugin is automatically available in your app through the default feature discovery. For more details and alternative installation methods, see installing plugins.

Troubleshooting

If you encounter issues with early closure of the EventStream used to auto-update logs during task execution, you can work around them by enabling long polling. To do so, update your packages/app/src/apis.ts file to register a ScaffolderClient with useLongPollingLogs set to true. By default, it is false.

import {
  AnyApiFactory,
  createApiFactory,
  discoveryApiRef,
  fetchApiRef,
  identityApiRef,
} from '@backstage/core-plugin-api';
import { scmIntegrationsApiRef } from '@backstage/integration-react';
import {
  scaffolderApiRef,
  ScaffolderClient,
} from '@backstage/plugin-scaffolder';

export const apis: AnyApiFactory[] = [
  createApiFactory({
    api: scaffolderApiRef,
    deps: {
      discoveryApi: discoveryApiRef,
      identityApi: identityApiRef,
      scmIntegrationsApi: scmIntegrationsApiRef,
      fetchApi: fetchApiRef,
    },
    factory: ({ scmIntegrationsApi, discoveryApi, identityApi, fetchApi }) =>
      new ScaffolderClient({
        discoveryApi,
        identityApi,
        scmIntegrationsApi,
        fetchApi,
        useLongPollingLogs: true,
      }),
  }),
  // ... other factories
];

This replaces the default implementation of the scaffolderApiRef.

Local development

When you develop a new template, action or new <ScaffolderFieldExtensions/>, then we recommend to launch the plugin locally using the createDevApp of the ./dev/index.tsx file for testing/Debugging purposes

To play with it, open a terminal and run the command: yarn start within the ./plugins/scaffolder folder

NOTE: Don't forget to open a second terminal, start your Backstage backend there, and configure the template locations that you want to test.

Old Frontend System

If your Backstage app uses the old frontend system, you need to manually wire the plugin into your app as outlined in this section. If you are on the new frontend system, you can skip this.

Add the plugin to your packages/app

Add the root page that the scaffolder plugin provides to your app. You can choose any path for the route, but we recommend the following:

// packages/app/src/App.tsx
+import { ScaffolderPage } from '@backstage/plugin-scaffolder';


<FlatRoutes>
  <Route path="/catalog" element={<CatalogIndexPage />} />
  <Route path="/catalog/:namespace/:kind/:name" element={<CatalogEntityPage />}>
    {entityPage}
  </Route>
+  <Route path="/create" element={<ScaffolderPage />} />;
  ...
</FlatRoutes>

The scaffolder plugin also has one external route that needs to be bound for it to function: the registerComponent route which should link to the page where the user can register existing software component. In a typical setup, the register component route will be linked to the catalog-import plugin's import page:

// packages/app/src/App.tsx
+import { scaffolderPlugin } from '@backstage/plugin-scaffolder';
+import { catalogImportPlugin } from '@backstage/plugin-catalog-import';

const app = createApp({
  // ...
  bindRoutes({ bind }) {
+    bind(scaffolderPlugin.externalRoutes, {
+      registerComponent: catalogImportPlugin.routes.importPage,
+    });
  },
});

You may also want to add a link to the scaffolder page to your application sidebar:

// packages/app/src/components/Root/Root.tsx
+import CreateComponentIcon from '@material-ui/icons/AddCircleOutline';

export const Root = ({ children }: PropsWithChildren<{}>) => (
  <SidebarPage>
    <Sidebar>
+      <SidebarItem icon={CreateComponentIcon} to="create" text="Create..." />;
      ...
    </Sidebar>

Links

• scaffolder-backend provides the backend API for this frontend.