feat(catalog/gerrit): Add backend plugin

Add `gerritEntityProviderCatalogModule` (new backend-plugin-api, alpha).

Relates-to: PR #13859
Signed-off-by: Patrick Jungermann <Patrick.Jungermann@gmail.com>

.changeset/metal-dogs-swim.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend-module-gerrit': patch
+---
+
+Add `gerritEntityProviderCatalogModule` (new backend-plugin-api, alpha).

plugins/catalog-backend-module-gerrit/api-report.md

@@ -3,6 +3,7 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
+import { BackendFeature } from '@backstage/backend-plugin-api';
 import { Config } from '@backstage/config';
 import { EntityProvider } from '@backstage/plugin-catalog-backend';
 import { EntityProviderConnection } from '@backstage/plugin-catalog-backend';
@@ -29,5 +30,10 @@ export class GerritEntityProvider implements EntityProvider {
   refresh(logger: Logger): Promise<void>;
 }
 
+// @alpha (undocumented)
+export const gerritEntityProviderCatalogModule: (
+  options?: undefined,
+) => BackendFeature;
+
 // (No @packageDocumentation comment for this package)
 ```

plugins/catalog-backend-module-gerrit/package.json

@@ -6,6 +6,7 @@
   "license": "Apache-2.0",
   "publishConfig": {
     "access": "public",
+    "alphaTypes": "dist/index.alpha.d.ts",
     "main": "dist/index.cjs.js",
     "types": "dist/index.d.ts"
   },
@@ -20,21 +21,23 @@
   },
   "scripts": {
     "start": "backstage-cli package start",
-    "build": "backstage-cli package build",
+    "build": "backstage-cli package build --experimental-type-build",
     "lint": "backstage-cli package lint",
     "test": "backstage-cli package test",
-    "clean": "backstage-cli package clean",
     "prepack": "backstage-cli package prepack",
-    "postpack": "backstage-cli package postpack"
+    "postpack": "backstage-cli package postpack",
+    "clean": "backstage-cli package clean"
   },
   "dependencies": {
     "@backstage/backend-common": "workspace:^",
+    "@backstage/backend-plugin-api": "workspace:^",
     "@backstage/backend-tasks": "workspace:^",
     "@backstage/catalog-model": "workspace:^",
     "@backstage/config": "workspace:^",
     "@backstage/errors": "workspace:^",
     "@backstage/integration": "workspace:^",
     "@backstage/plugin-catalog-backend": "workspace:^",
+    "@backstage/plugin-catalog-node": "workspace:^",
     "fs-extra": "10.1.0",
     "msw": "^0.47.0",
     "node-fetch": "^2.6.7",

plugins/catalog-backend-module-gerrit/src/index.ts

@@ -15,3 +15,4 @@
  */
 
 export { GerritEntityProvider } from './providers/GerritEntityProvider';
+export { gerritEntityProviderCatalogModule } from './service/GerritEntityProviderCatalogModule';

plugins/catalog-backend-module-gerrit/src/service/GerritEntityProviderCatalogModule.test.ts

@@ -0,0 +1,97 @@
+/*
+ * 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 { getVoidLogger } from '@backstage/backend-common';
+import {
+  configServiceRef,
+  loggerServiceRef,
+  schedulerServiceRef,
+} from '@backstage/backend-plugin-api';
+import {
+  PluginTaskScheduler,
+  TaskScheduleDefinition,
+} from '@backstage/backend-tasks';
+import { startTestBackend } from '@backstage/backend-test-utils';
+import { ConfigReader } from '@backstage/config';
+import { catalogProcessingExtensionPoint } from '@backstage/plugin-catalog-node';
+import { Duration } from 'luxon';
+import { gerritEntityProviderCatalogModule } from './GerritEntityProviderCatalogModule';
+import { GerritEntityProvider } from '../providers/GerritEntityProvider';
+
+describe('gerritEntityProviderCatalogModule', () => {
+  it('should register provider at the catalog extension point', async () => {
+    let addedProviders: Array<GerritEntityProvider> | undefined;
+    let usedSchedule: TaskScheduleDefinition | undefined;
+
+    const extensionPoint = {
+      addEntityProvider: (providers: any) => {
+        addedProviders = providers;
+      },
+    };
+    const runner = jest.fn();
+    const scheduler = {
+      createScheduledTaskRunner: (schedule: TaskScheduleDefinition) => {
+        usedSchedule = schedule;
+        return runner;
+      },
+    } as unknown as PluginTaskScheduler;
+
+    const config = new ConfigReader({
+      catalog: {
+        providers: {
+          gerrit: {
+            test: {
+              host: 'g.com',
+              query: 'state=ACTIVE&prefix=training',
+              branch: 'main',
+              schedule: {
+                frequency: 'P1M',
+                timeout: 'PT3M',
+              },
+            },
+          },
+        },
+      },
+      integrations: {
+        gerrit: [
+          {
+            host: 'g.com',
+            baseUrl: 'https://g.com/gerrit',
+            gitilesBaseUrl: 'https:/g.com/gitiles',
+          },
+        ],
+      },
+    });
+
+    await startTestBackend({
+      extensionPoints: [[catalogProcessingExtensionPoint, extensionPoint]],
+      services: [
+        [configServiceRef, config],
+        [loggerServiceRef, getVoidLogger()],
+        [schedulerServiceRef, scheduler],
+      ],
+      features: [gerritEntityProviderCatalogModule()],
+    });
+
+    expect(usedSchedule?.frequency).toEqual(Duration.fromISO('P1M'));
+    expect(usedSchedule?.timeout).toEqual(Duration.fromISO('PT3M'));
+    expect(addedProviders?.length).toEqual(1);
+    expect(addedProviders?.pop()?.getProviderName()).toEqual(
+      'gerrit-provider:test',
+    );
+    expect(runner).not.toHaveBeenCalled();
+  });
+});

plugins/catalog-backend-module-gerrit/src/service/GerritEntityProviderCatalogModule.ts

@@ -0,0 +1,52 @@
+/*
+ * 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,
+  createBackendModule,
+  loggerServiceRef,
+  loggerToWinstonLogger,
+  schedulerServiceRef,
+} from '@backstage/backend-plugin-api';
+import { catalogProcessingExtensionPoint } from '@backstage/plugin-catalog-node';
+import { GerritEntityProvider } from '../providers/GerritEntityProvider';
+
+/**
+ * @alpha
+ */
+export const gerritEntityProviderCatalogModule = createBackendModule({
+  pluginId: 'catalog',
+  moduleId: 'gerritEntityProvider',
+  register(env) {
+    env.registerInit({
+      deps: {
+        catalog: catalogProcessingExtensionPoint,
+        config: configServiceRef,
+        logger: loggerServiceRef,
+        scheduler: schedulerServiceRef,
+      },
+      async init({ catalog, config, logger, scheduler }) {
+        const winstonLogger = loggerToWinstonLogger(logger);
+        const providers = GerritEntityProvider.fromConfig(config, {
+          logger: winstonLogger,
+          scheduler,
+        });
+
+        catalog.addEntityProvider(providers);
+      },
+    });
+  },
+});

yarn.lock

@@ -4559,6 +4559,7 @@ __metadata:
   resolution: "@backstage/plugin-catalog-backend-module-gerrit@workspace:plugins/catalog-backend-module-gerrit"
   dependencies:
     "@backstage/backend-common": "workspace:^"
+    "@backstage/backend-plugin-api": "workspace:^"
     "@backstage/backend-tasks": "workspace:^"
     "@backstage/backend-test-utils": "workspace:^"
     "@backstage/catalog-model": "workspace:^"
@@ -4567,6 +4568,7 @@ __metadata:
     "@backstage/errors": "workspace:^"
     "@backstage/integration": "workspace:^"
     "@backstage/plugin-catalog-backend": "workspace:^"
+    "@backstage/plugin-catalog-node": "workspace:^"
     "@types/fs-extra": ^9.0.1
     fs-extra: 10.1.0
     luxon: ^3.0.0