Pass in event broker to notify on conflicts

Signed-off-by: sblausten <sam@roadie.io>

packages/backend/src/plugins/catalog.ts

@@ -19,14 +19,28 @@ import { EntityProvider } from '@backstage/plugin-catalog-node';
 import { ScaffolderEntitiesProcessor } from '@backstage/plugin-scaffolder-backend';
 import { Router } from 'express';
 import { PluginEnvironment } from '../types';
+import { InMemoryEventBroker } from '@backstage/plugin-events-backend';
+import { GithubEntityProvider } from '@backstage/plugin-catalog-backend-module-github';
 
 export default async function createPlugin(
   env: PluginEnvironment,
   providers?: Array<EntityProvider>,
 ): Promise<Router> {
   const builder = await CatalogBuilder.create(env);
+  const githubEntityProviders = GithubEntityProvider.fromConfig(env.config, {
+    logger: env.logger,
+    // optional: alternatively, use scheduler with schedule defined in app-config.yaml
+    schedule: env.scheduler.createScheduledTaskRunner({
+      frequency: { minutes: 5 },
+      timeout: { minutes: 3 },
+    }),
+    scheduler: env.scheduler,
+  });
+  builder.addEntityProvider(githubEntityProviders);
   builder.addProcessor(new ScaffolderEntitiesProcessor());
   builder.addEntityProvider(providers ?? []);
+  const conflictBroker = new InMemoryEventBroker(env.logger);
+  builder.setConflictEventBroker(conflictBroker);
   const { processingEngine, router } = await builder.build();
   await processingEngine.start();
   return router;

plugins/catalog-backend/package.json

@@ -54,6 +54,7 @@
     "@backstage/integration": "workspace:^",
     "@backstage/plugin-catalog-common": "workspace:^",
     "@backstage/plugin-catalog-node": "workspace:^",
+    "@backstage/plugin-events-node": "workspace:^",
     "@backstage/plugin-permission-common": "workspace:^",
     "@backstage/plugin-permission-node": "workspace:^",
     "@backstage/plugin-scaffolder-common": "workspace:^",

plugins/catalog-backend/src/database/DefaultProcessingDatabase.ts

@@ -44,6 +44,7 @@ import { checkLocationKeyConflict } from './operations/refreshState/checkLocatio
 import { insertUnprocessedEntity } from './operations/refreshState/insertUnprocessedEntity';
 import { updateUnprocessedEntity } from './operations/refreshState/updateUnprocessedEntity';
 import { generateStableHash } from './util';
+import { EventBroker } from '@backstage/plugin-events-node';
 
 // The number of items that are sent per batch to the database layer, when
 // doing .batchInsert calls to knex. This needs to be low enough to not cause
@@ -57,6 +58,7 @@ export class DefaultProcessingDatabase implements ProcessingDatabase {
       database: Knex;
       logger: Logger;
       refreshInterval: ProcessingIntervalFunction;
+      conflictEventBroker?: EventBroker;
     },
   ) {
     initDatabaseMetrics(options.database);
@@ -356,6 +358,18 @@ export class DefaultProcessingDatabase implements ProcessingDatabase {
         this.options.logger.warn(
           `Detected conflicting entityRef ${entityRef} already referenced by ${conflictingKey} and now also ${locationKey}`,
         );
+        if (this.options.conflictEventBroker) {
+          this.options.conflictEventBroker?.publish({
+            topic: 'conflicting-entities',
+            eventPayload: {
+              ...entity,
+              entityRef,
+              newLocationKey: locationKey,
+              existingLocationKey: conflictingKey,
+            },
+            metadata: {},
+          });
+        }
       }
     }
 

plugins/catalog-backend/src/service/CatalogBuilder.ts

@@ -98,6 +98,7 @@ import {
 import { AuthorizedLocationService } from './AuthorizedLocationService';
 import { DefaultProviderDatabase } from '../database/DefaultProviderDatabase';
 import { DefaultCatalogDatabase } from '../database/DefaultCatalogDatabase';
+import { EventBroker } from '@backstage/plugin-events-node';
 
 /**
  * This is a duplicate of the alpha `CatalogPermissionRule` type, for use in the stable API.
@@ -166,6 +167,7 @@ export class CatalogBuilder {
   private readonly permissionRules: CatalogPermissionRuleInput[];
   private allowedLocationType: string[];
   private legacySingleProcessorValidation = false;
+  private conflictEventBroker?: EventBroker;
 
   /**
    * Creates a catalog builder.
@@ -417,6 +419,11 @@ export class CatalogBuilder {
     return this;
   }
 
+  setConflictEventBroker(broker: EventBroker): CatalogBuilder {
+    this.conflictEventBroker = broker;
+    return this;
+  }
+
   /**
    * Wires up and returns all of the component parts of the catalog
    */
@@ -440,6 +447,7 @@ export class CatalogBuilder {
       database: dbClient,
       logger,
       refreshInterval: this.processingInterval,
+      conflictEventBroker: this.conflictEventBroker,
     });
     const providerDatabase = new DefaultProviderDatabase({
       database: dbClient,

plugins/events-backend/src/index.ts

@@ -21,4 +21,5 @@
  */
 
 export { EventsBackend } from './service/EventsBackend';
+export { InMemoryEventBroker } from './service/InMemoryEventBroker';
 export { HttpPostIngressEventPublisher } from './service/http';

yarn.lock

@@ -5006,7 +5006,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@backstage/plugin-catalog-backend-module-github@workspace:plugins/catalog-backend-module-github":
+"@backstage/plugin-catalog-backend-module-github@workspace:^, @backstage/plugin-catalog-backend-module-github@workspace:plugins/catalog-backend-module-github":
   version: 0.0.0-use.local
   resolution: "@backstage/plugin-catalog-backend-module-github@workspace:plugins/catalog-backend-module-github"
   dependencies:
@@ -5204,6 +5204,7 @@ __metadata:
     "@backstage/integration": "workspace:^"
     "@backstage/plugin-catalog-common": "workspace:^"
     "@backstage/plugin-catalog-node": "workspace:^"
+    "@backstage/plugin-events-node": "workspace:^"
     "@backstage/plugin-permission-common": "workspace:^"
     "@backstage/plugin-permission-node": "workspace:^"
     "@backstage/plugin-scaffolder-common": "workspace:^"
@@ -22508,6 +22509,7 @@ __metadata:
     "@backstage/plugin-azure-sites-backend": "workspace:^"
     "@backstage/plugin-badges-backend": "workspace:^"
     "@backstage/plugin-catalog-backend": "workspace:^"
+    "@backstage/plugin-catalog-backend-module-github": "workspace:^"
     "@backstage/plugin-catalog-node": "workspace:^"
     "@backstage/plugin-code-coverage-backend": "workspace:^"
     "@backstage/plugin-entity-feedback-backend": "workspace:^"