Merge pull request #22568 from sennyeya/catalog-entity-policies

feat(catalog): add support for entity policies in the new backend.

.changeset/thirty-bags-try.md

@@ -0,0 +1,33 @@
+---
+'@backstage/plugin-catalog-backend': minor
+'@backstage/plugin-catalog-node': minor
+---
+
+Adds support for supplying field validators to the new backend's catalog plugin. If you're using entity policies, you should use the new `transformLegacyPolicyToProcessor` function to install them as processors instead.
+
+```ts
+import {
+  catalogProcessingExtensionPoint,
+  catalogModelExtensionPoint,
+} from '@backstage/plugin-catalog-node/alpha';
+import {myPolicy} from './my-policy';
+
+export const catalogModulePolicyProvider = createBackendModule({
+  pluginId: 'catalog',
+  moduleId: 'internal-policy-provider',
+  register(reg) {
+    reg.registerInit({
+      deps: {
+        modelExtensions: catalogModelExtensionPoint,
+        processingExtensions: catalogProcessingExtensionPoint,
+      },
+      async init({ modelExtensions, processingExtensions }) {
+        modelExtensions.setFieldValidators({
+          ...
+        });
+        processingExtensions.addProcessors(transformLegacyPolicyToProcessor(myPolicy))
+      },
+    });
+  },
+});
+```

plugins/catalog-backend/src/modules/core/index.ts

@@ -24,3 +24,4 @@ export { PlaceholderProcessor } from './PlaceholderProcessor';
 export type { PlaceholderProcessorOptions } from './PlaceholderProcessor';
 export { UrlReaderProcessor } from './UrlReaderProcessor';
 export { parseEntityYaml } from '../util/parse';
+export { transformLegacyPolicyToProcessor } from './transformLegacyPolicyToProcessor';

plugins/catalog-backend/src/modules/core/transformLegacyPolicyToProcessor.test.ts

@@ -0,0 +1,90 @@
+/*
+ * Copyright 2024 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 { Entity, EntityPolicy } from '@backstage/catalog-model';
+import { transformLegacyPolicyToProcessor } from './transformLegacyPolicyToProcessor';
+import { clone } from 'lodash';
+
+describe('transformLegacyPolicyToProcessor', () => {
+  const entityToProcess: Entity = {
+    apiVersion: 'backstage.io/v1alpha',
+    kind: 'Component',
+    metadata: {
+      name: 'test',
+    },
+  };
+  it('modifies the entity if the policy modifies the entity', async () => {
+    const policy: EntityPolicy = {
+      async enforce(entity) {
+        entity.kind = 'Group';
+        return entity;
+      },
+    };
+    const processor = transformLegacyPolicyToProcessor(policy);
+    const clonedEntity = clone(entityToProcess);
+    const entity = await processor.preProcessEntity?.(
+      clonedEntity,
+      {} as any,
+      jest.fn(),
+      {} as any,
+      {} as any,
+    );
+    expect(entity).toBeTruthy();
+    expect(entity?.kind).toBe('Group');
+    expect(entity?.apiVersion).toBe('backstage.io/v1alpha');
+    expect(entity?.metadata.name).toBe('test');
+  });
+
+  it('does not modify the entity if the policy returns undefined', async () => {
+    const policy: EntityPolicy = {
+      async enforce() {
+        return undefined;
+      },
+    };
+    const processor = transformLegacyPolicyToProcessor(policy);
+    const clonedEntity = clone(entityToProcess);
+    const entity = await processor.preProcessEntity?.(
+      clonedEntity,
+      {} as any,
+      jest.fn(),
+      {} as any,
+      {} as any,
+    );
+    expect(entity).toBeTruthy();
+    expect(entity?.kind).toBe('Component');
+    expect(entity?.apiVersion).toBe('backstage.io/v1alpha');
+    expect(entity?.metadata.name).toBe('test');
+  });
+
+  it('bubbles up processor error', async () => {
+    const policy: EntityPolicy = {
+      async enforce() {
+        throw new TypeError('Invalid value for metadata.name');
+      },
+    };
+    const processor = transformLegacyPolicyToProcessor(policy);
+    const clonedEntity = clone(entityToProcess);
+    await expect(
+      processor.preProcessEntity?.(
+        clonedEntity,
+        {} as any,
+        jest.fn(),
+        {} as any,
+        {} as any,
+      ),
+    ).rejects.toThrow(/Invalid value for metadata.name/);
+  });
+});

plugins/catalog-backend/src/modules/core/transformLegacyPolicyToProcessor.ts

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2024 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 { EntityPolicy } from '@backstage/catalog-model';
+import { CatalogProcessor } from '@backstage/plugin-catalog-node';
+
+/**
+ * Transform a given entity policy to an entity processor.
+ * @param policy - The policy to transform
+ * @returns A new entity processor that uses the entity policy.
+ * @public
+ */
+export function transformLegacyPolicyToProcessor(
+  policy: EntityPolicy,
+): CatalogProcessor {
+  return {
+    getProcessorName() {
+      return policy.constructor.name;
+    },
+    async preProcessEntity(entity) {
+      // If enforcing the policy fails, throw the policy error.
+      const result = await policy.enforce(entity);
+      if (!result) {
+        return entity;
+      }
+      return result;
+    },
+  };
+}

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

@@ -17,7 +17,7 @@ import {
   createBackendPlugin,
   coreServices,
 } from '@backstage/backend-plugin-api';
-import { Entity } from '@backstage/catalog-model';
+import { Entity, Validators } from '@backstage/catalog-model';
 import { CatalogBuilder, CatalogPermissionRuleInput } from './CatalogBuilder';
 import {
   CatalogAnalysisExtensionPoint,
@@ -26,6 +26,8 @@ import {
   catalogProcessingExtensionPoint,
   CatalogPermissionExtensionPoint,
   catalogPermissionExtensionPoint,
+  CatalogModelExtensionPoint,
+  catalogModelExtensionPoint,
 } from '@backstage/plugin-catalog-node/alpha';
 import {
   CatalogProcessor,
@@ -34,6 +36,7 @@ import {
   ScmLocationAnalyzer,
 } from '@backstage/plugin-catalog-node';
 import { loggerToWinstonLogger } from '@backstage/backend-common';
+import { merge } from 'lodash';
 
 class CatalogProcessingExtensionPointImpl
   implements CatalogProcessingExtensionPoint
@@ -124,6 +127,18 @@ class CatalogPermissionExtensionPointImpl
   }
 }
 
+class CatalogModelExtensionPointImpl implements CatalogModelExtensionPoint {
+  #fieldValidators: Partial<Validators> = {};
+
+  setFieldValidators(validators: Partial<Validators>): void {
+    merge(this.#fieldValidators, validators);
+  }
+
+  get fieldValidators() {
+    return this.#fieldValidators;
+  }
+}
+
 /**
  * Catalog plugin
  * @alpha
@@ -150,6 +165,9 @@ export const catalogPlugin = createBackendPlugin({
       permissionExtensions,
     );
 
+    const modelExtensions = new CatalogModelExtensionPointImpl();
+    env.registerExtensionPoint(catalogModelExtensionPoint, modelExtensions);
+
     env.registerInit({
       deps: {
         logger: coreServices.logger,
@@ -192,6 +210,7 @@ export const catalogPlugin = createBackendPlugin({
         );
         builder.addLocationAnalyzers(...analysisExtensions.locationAnalyzers);
         builder.addPermissionRules(...permissionExtensions.permissionRules);
+        builder.setFieldFormatValidators(modelExtensions.fieldValidators);
 
         const { processingEngine, router } = await builder.build();
 

plugins/catalog-node/src/alpha.ts

@@ -22,3 +22,5 @@ export { catalogAnalysisExtensionPoint } from './extensions';
 export type { CatalogPermissionRuleInput } from './extensions';
 export type { CatalogPermissionExtensionPoint } from './extensions';
 export { catalogPermissionExtensionPoint } from './extensions';
+export type { CatalogModelExtensionPoint } from './extensions';
+export { catalogModelExtensionPoint } from './extensions';

plugins/catalog-node/src/extensions.ts

@@ -15,7 +15,7 @@
  */
 
 import { createExtensionPoint } from '@backstage/backend-plugin-api';
-import { Entity } from '@backstage/catalog-model';
+import { Entity, Validators } from '@backstage/catalog-model';
 import {
   CatalogProcessor,
   EntitiesSearchFilter,
@@ -45,6 +45,18 @@ export interface CatalogProcessingExtensionPoint {
   ): void;
 }
 
+/** @alpha */
+export interface CatalogModelExtensionPoint {
+  /**
+   * Sets the validator function to use for one or more special fields of an
+   * entity. This is useful if the default rules for formatting of fields are
+   * not sufficient.
+   *
+   * @param validators - The (subset of) validators to set
+   */
+  setFieldValidators(validators: Partial<Validators>): void;
+}
+
 /**
  * @alpha
  */
@@ -68,6 +80,12 @@ export const catalogAnalysisExtensionPoint =
     id: 'catalog.analysis',
   });
 
+/** @alpha */
+export const catalogModelExtensionPoint =
+  createExtensionPoint<CatalogModelExtensionPoint>({
+    id: 'catalog.model',
+  });
+
 /**
  * @alpha
  */