Merge pull request #23682 from Bonial-International-GmbH/pjungermann/events-service/github

feat(events,github): add support for EventsService, events at new backend

.changeset/nervous-mangos-peel.md

@@ -0,0 +1,24 @@
+---
+'@backstage/plugin-catalog-backend-module-github': patch
+---
+
+Support EventsService and events with the new backend system (through EventsService).
+
+_New/Current Backend System:_
+
+The events support for the provider will be enabled always, making it ready to consume events from its subscribed topics.
+In order to receive events and make use of this feature, you still need to set up receiving events from the event source as before.
+
+_Legacy Backend System:_
+
+You can pass the `EventsService` instance to the factory method as one of its options:
+
+```diff
+  // packages/backend/src/plugins/catalog.ts
+  const githubProvider = GithubEntityProvider.fromConfig(env.config, {
++   events: env.events,
+    logger: env.logger,
+    scheduler: env.scheduler,
+  });
+- env.eventBroker.subscribe(githubProvider);
+```

docs/integrations/github/discovery.md

@@ -51,6 +51,26 @@ export default async function createPlugin(
 
 ## Installation with Events Support
 
+_For the legacy backend system, please read the sub-section below._
+
+The catalog module for GitHub comes with events support enabled.
+This will make it subscribe to its relevant topics (`github.push`)
+and expects these events to be published via the `EventsService`.
+
+Additionally, you should install the
+[event router by `events-backend-module-github`](https://github.com/backstage/backstage/tree/master/plugins/events-backend-module-github/README.md)
+which will route received events from the generic topic `github` to more specific ones
+based on the event type (e.g., `github.push`).
+
+In order to receive Webhook events by GitHub, you have to decide how you want them
+to be ingested into Backstage and published to its `EventsService`.
+You can decide between the following options (extensible):
+
+- [via HTTP endpoint](https://github.com/backstage/backstage/tree/master/plugins/events-backend/README.md)
+- [via an AWS SQS queue](https://github.com/backstage/backstage/tree/master/plugins/events-backend-module-aws-sqs/README.md)
+
+### Legacy Backend System
+
 Please follow the installation instructions at
 
 - <https://github.com/backstage/backstage/tree/master/plugins/events-backend/README.md>
@@ -78,10 +98,10 @@ export default async function createPlugin(
   builder.addProcessor(new ScaffolderEntitiesProcessor());
   /* highlight-add-start */
   const githubProvider = GithubEntityProvider.fromConfig(env.config, {
+    events: env.events,
     logger: env.logger,
     scheduler: env.scheduler,
   });
-  env.eventBroker.subscribe(githubProvider);
   builder.addEntityProvider(githubProvider);
   /* highlight-add-end */
   const { processingEngine, router } = await builder.build();

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

@@ -13,6 +13,7 @@ import { EntityProvider } from '@backstage/plugin-catalog-node';
 import { EntityProviderConnection } from '@backstage/plugin-catalog-node';
 import { EventBroker } from '@backstage/plugin-events-node';
 import { EventParams } from '@backstage/plugin-events-node';
+import { EventsService } from '@backstage/plugin-events-node';
 import { EventSubscriber } from '@backstage/plugin-events-node';
 import { GithubCredentialsProvider } from '@backstage/integration';
 import { GithubIntegrationConfig } from '@backstage/integration';
@@ -88,6 +89,7 @@ export class GithubEntityProvider implements EntityProvider, EventSubscriber {
   static fromConfig(
     config: Config,
     options: {
+      events?: EventsService;
       logger: Logger;
       schedule?: TaskRunner;
       scheduler?: PluginTaskScheduler;

plugins/catalog-backend-module-github/src/module/githubCatalogModule.ts

@@ -23,6 +23,7 @@ import {
   catalogAnalysisExtensionPoint,
   catalogProcessingExtensionPoint,
 } from '@backstage/plugin-catalog-node/alpha';
+import { eventsServiceRef } from '@backstage/plugin-events-node';
 import { GithubEntityProvider } from '../providers/GithubEntityProvider';
 import { GithubLocationAnalyzer } from '../analyzers/GithubLocationAnalyzer';
 
@@ -37,17 +38,19 @@ export const githubCatalogModule = createBackendModule({
   register(env) {
     env.registerInit({
       deps: {
-        catalog: catalogProcessingExtensionPoint,
         analyzers: catalogAnalysisExtensionPoint,
         auth: coreServices.auth,
-        discovery: coreServices.discovery,
+        catalog: catalogProcessingExtensionPoint,
         config: coreServices.rootConfig,
+        discovery: coreServices.discovery,
+        events: eventsServiceRef,
         logger: coreServices.logger,
         scheduler: coreServices.scheduler,
       },
       async init({
         catalog,
         config,
+        events,
         logger,
         scheduler,
         analyzers,
@@ -64,6 +67,7 @@ export const githubCatalogModule = createBackendModule({
 
         catalog.addEntityProvider(
           GithubEntityProvider.fromConfig(config, {
+            events,
             logger: loggerToWinstonLogger(logger),
             scheduler,
           }),

plugins/catalog-backend-module-github/src/providers/GithubEntityProvider.ts

@@ -46,7 +46,11 @@ import {
   satisfiesVisibilityFilter,
 } from '../lib/util';
 
-import { EventParams, EventSubscriber } from '@backstage/plugin-events-node';
+import {
+  EventParams,
+  EventsService,
+  EventSubscriber,
+} from '@backstage/plugin-events-node';
 import { PushEvent, Commit } from '@octokit/webhooks-types';
 import { Minimatch } from 'minimatch';
 
@@ -73,6 +77,7 @@ type Repository = {
  */
 export class GithubEntityProvider implements EntityProvider, EventSubscriber {
   private readonly config: GithubEntityProviderConfig;
+  private readonly events?: EventsService;
   private readonly logger: Logger;
   private readonly integration: GithubIntegrationConfig;
   private readonly scheduleFn: () => Promise<void>;
@@ -82,6 +87,7 @@ export class GithubEntityProvider implements EntityProvider, EventSubscriber {
   static fromConfig(
     config: Config,
     options: {
+      events?: EventsService;
       logger: Logger;
       schedule?: TaskRunner;
       scheduler?: PluginTaskScheduler;
@@ -118,6 +124,7 @@ export class GithubEntityProvider implements EntityProvider, EventSubscriber {
         integration,
         options.logger,
         taskRunner,
+        options.events,
       );
     });
   }
@@ -127,8 +134,10 @@ export class GithubEntityProvider implements EntityProvider, EventSubscriber {
     integration: GithubIntegration,
     logger: Logger,
     taskRunner: TaskRunner,
+    events?: EventsService,
   ) {
     this.config = config;
+    this.events = events;
     this.integration = integration.config;
     this.logger = logger.child({
       target: this.getProviderName(),
@@ -146,6 +155,11 @@ export class GithubEntityProvider implements EntityProvider, EventSubscriber {
   /** {@inheritdoc @backstage/plugin-catalog-backend#EntityProvider.connect} */
   async connect(connection: EntityProviderConnection): Promise<void> {
     this.connection = connection;
+    await this.events?.subscribe({
+      id: this.getProviderName(),
+      topics: [TOPIC_REPO_PUSH],
+      onEvent: params => this.onEvent(params),
+    });
     return await this.scheduleFn();
   }