Implement NextCatalogBuilder.addEntityProvider

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

.changeset/nice-dryers-dream.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-catalog-backend': patch
+---
+
+Implement `NextCatalogBuilder.addEntityProvider`

plugins/catalog-backend/src/next/NextCatalogBuilder.ts

@@ -63,7 +63,11 @@ import {
 } from '../ingestion/processors/PlaceholderProcessor';
 import { defaultEntityDataParser } from '../ingestion/processors/util/parse';
 import { LocationAnalyzer } from '../ingestion/types';
-import { CatalogProcessingEngine, LocationService } from '../next/types';
+import {
+  CatalogProcessingEngine,
+  EntityProvider,
+  LocationService,
+} from '../next/types';
 import { ConfigLocationEntityProvider } from './ConfigLocationEntityProvider';
 import { DefaultProcessingDatabase } from './database/DefaultProcessingDatabase';
 import { DefaultCatalogProcessingEngine } from './DefaultCatalogProcessingEngine';
@@ -105,6 +109,7 @@ export class NextCatalogBuilder {
   private entityPoliciesReplace: boolean;
   private placeholderResolvers: Record<string, PlaceholderResolver>;
   private fieldFormatValidators: Partial<Validators>;
+  private entityProviders: EntityProvider[];
   private processors: CatalogProcessor[];
   private processorsReplace: boolean;
   private parser: CatalogProcessorParser | undefined;
@@ -116,6 +121,7 @@ export class NextCatalogBuilder {
     this.entityPoliciesReplace = false;
     this.placeholderResolvers = {};
     this.fieldFormatValidators = {};
+    this.entityProviders = [];
     this.processors = [];
     this.processorsReplace = false;
     this.parser = undefined;
@@ -198,6 +204,20 @@ export class NextCatalogBuilder {
     return this;
   }
 
+  /**
+   * Adds or replaces entity providers. These are responsible for bootstrapping
+   * the list of entities out of original data sources. For example, there is
+   * one entity source for the config locations, and one for the database
+   * stored locations. If you ingest entities out of a third party system, you
+   * may want to implement that in terms of an entity provider as well.
+   *
+   * @param providers One or more entity providers
+   */
+  addEntityProvider(...providers: EntityProvider[]): NextCatalogBuilder {
+    this.entityProviders.push(...providers);
+    return this;
+  }
+
   /**
    * Adds entity processors. These are responsible for reading, parsing, and
    * processing entities before they are persisted in the catalog.
@@ -277,13 +297,18 @@ export class NextCatalogBuilder {
       policy,
     });
     const entitiesCatalog = new NextEntitiesCatalog(dbClient);
+    const stitcher = new Stitcher(dbClient, logger);
 
     const locationStore = new DefaultLocationStore(dbClient);
-    const stitcher = new Stitcher(dbClient, logger);
     const configLocationProvider = new ConfigLocationEntityProvider(config);
+    const entityProviders = lodash.uniqBy(
+      [...this.entityProviders, locationStore, configLocationProvider],
+      provider => provider.getProviderName(),
+    );
+
     const processingEngine = new DefaultCatalogProcessingEngine(
       logger,
-      [locationStore, configLocationProvider],
+      entityProviders,
       processingDatabase,
       orchestrator,
       stitcher,
@@ -295,6 +320,7 @@ export class NextCatalogBuilder {
       locationStore,
       orchestrator,
     );
+
     return {
       entitiesCatalog,
       locationsCatalog,