From ef875b07c330ba0163945bd0c8315e58b203e92e Mon Sep 17 00:00:00 2001
From: Johan Haals <johan.haals@gmail.com>
Date: Tue, 30 Aug 2022 15:15:33 +0200
Subject: [PATCH] Add experimental ScaffolderPlugin

Signed-off-by: Johan Haals <johan.haals@gmail.com>
---
 .../src/ScaffolderPlugin.ts                   | 138 ++++++++++++++++++
 plugins/scaffolder-backend/src/index.ts       |   1 +
 2 files changed, 139 insertions(+)
 create mode 100644 plugins/scaffolder-backend/src/ScaffolderPlugin.ts

diff --git a/plugins/scaffolder-backend/src/ScaffolderPlugin.ts b/plugins/scaffolder-backend/src/ScaffolderPlugin.ts
new file mode 100644
index 0000000000..5f69484179
--- /dev/null
+++ b/plugins/scaffolder-backend/src/ScaffolderPlugin.ts
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {
+  configServiceRef,
+  createBackendPlugin,
+  databaseServiceRef,
+  loggerServiceRef,
+  loggerToWinstonLogger,
+  permissionsServiceRef,
+  urlReaderServiceRef,
+  httpRouterServiceRef,
+  createExtensionPoint,
+} from '@backstage/backend-plugin-api';
+import { ScmIntegrations } from '@backstage/integration';
+import { catalogServiceRef } from '@backstage/plugin-catalog-node';
+import { TemplateFilter } from './lib';
+import { createBuiltinActions, TaskBroker, TemplateAction } from './scaffolder';
+import { createRouter } from './service/router';
+
+/**
+ * Catalog plugin options
+ * @alpha
+ */
+export type ScaffolderPluginOptions = {
+  actions?: TemplateAction<any>[];
+  taskWorkers?: number;
+  taskBroker?: TaskBroker;
+  additionalTemplateFilters?: Record<string, TemplateFilter>;
+};
+
+/**
+ * @alpha
+ * TODO: MOVE to catalog-node before merge.
+ */
+interface ScaffolderActionsExtensionPoint {
+  addActions(...actions: TemplateAction<any>[]): void;
+}
+
+class ScaffolderActionsExtensionPointImpl
+  implements ScaffolderActionsExtensionPoint
+{
+  #actions = new Array<TemplateAction<any>>();
+  addActions(...actions: TemplateAction<any>[]): void {
+    this.#actions.push(...actions);
+  }
+  get actions() {
+    return this.#actions;
+  }
+}
+
+/**
+ * @alpha
+ * TODO: MOVE to catalog-node before merge.
+ */
+export const scaffolderActionsExtensionPoint =
+  createExtensionPoint<ScaffolderActionsExtensionPoint>({
+    id: 'scaffolder.actions',
+  });
+
+/**
+ * Catalog plugin
+ * @alpha
+ */
+export const scaffolderPlugin = createBackendPlugin({
+  id: 'scaffolder',
+  register(env, options: ScaffolderPluginOptions) {
+    const actionsExtensions = new ScaffolderActionsExtensionPointImpl();
+    env.registerExtensionPoint(
+      scaffolderActionsExtensionPoint,
+      actionsExtensions,
+    );
+
+    env.registerInit({
+      deps: {
+        logger: loggerServiceRef,
+        config: configServiceRef,
+        reader: urlReaderServiceRef,
+        permissions: permissionsServiceRef,
+        database: databaseServiceRef,
+        httpRouter: httpRouterServiceRef,
+        catalogClient: catalogServiceRef,
+      },
+      async init({
+        logger,
+        config,
+        reader,
+        database,
+        httpRouter,
+        catalogClient,
+      }) {
+        const { additionalTemplateFilters, taskBroker, taskWorkers } = options;
+        const log = loggerToWinstonLogger(logger);
+
+        const actions = options.actions || [
+          ...actionsExtensions.actions,
+          ...createBuiltinActions({
+            integrations: ScmIntegrations.fromConfig(config),
+            catalogClient,
+            reader,
+            config,
+            additionalTemplateFilters,
+          }),
+        ];
+
+        const actionIds = actions.map(action => action.id).join(', ');
+        log.info(
+          `Starting scaffolder with the following actions enabled ${actionIds}`,
+        );
+
+        const router = await createRouter({
+          logger: log,
+          config,
+          database,
+          catalogClient,
+          reader,
+          actions,
+          taskBroker,
+          taskWorkers,
+          additionalTemplateFilters,
+        });
+        httpRouter.use(router);
+      },
+    });
+  },
+});
diff --git a/plugins/scaffolder-backend/src/index.ts b/plugins/scaffolder-backend/src/index.ts
index a1032449d5..a511aa8776 100644
--- a/plugins/scaffolder-backend/src/index.ts
+++ b/plugins/scaffolder-backend/src/index.ts
@@ -25,3 +25,4 @@ export * from './service/router';
 export * from './lib';
 export * from './processor';
 export * from './extension';
+export { scaffolderPlugin } from './ScaffolderPlugin';