Use CachedEntityLoader in techdocs router

Signed-off-by: Joe Porpeglia <josephp@spotify.com>

plugins/techdocs-backend/src/service/router.test.ts

@@ -17,9 +17,9 @@
 import {
   errorHandler,
   getVoidLogger,
+  PluginCacheManager,
   PluginEndpointDiscovery,
 } from '@backstage/backend-common';
-import { CatalogClient } from '@backstage/catalog-client';
 import { ConfigReader } from '@backstage/config';
 import { NotModifiedError } from '@backstage/errors';
 import {
@@ -30,21 +30,23 @@ import {
 import express, { Response } from 'express';
 import request from 'supertest';
 import { DocsSynchronizer, DocsSynchronizerSyncOpts } from './DocsSynchronizer';
+import { CachedEntityLoader } from './CachedEntityLoader';
 import { createEventStream, createHttpResponse, createRouter } from './router';
 
 jest.mock('@backstage/catalog-client');
 jest.mock('@backstage/config');
+jest.mock('./CachedEntityLoader');
 jest.mock('./DocsSynchronizer');
 
 const MockedConfigReader = ConfigReader as jest.MockedClass<
   typeof ConfigReader
 >;
-const MockCatalogClient = CatalogClient as jest.MockedClass<
-  typeof CatalogClient
->;
 const MockDocsSynchronizer = DocsSynchronizer as jest.MockedClass<
   typeof DocsSynchronizer
 >;
+const MockCachedEntityLoader = CachedEntityLoader as jest.MockedClass<
+  typeof CachedEntityLoader
+>;
 
 describe('createRouter', () => {
   const entity = {
@@ -82,6 +84,9 @@ describe('createRouter', () => {
     getBaseUrl: jest.fn(),
     getExternalBaseUrl: jest.fn(),
   };
+  const cache: jest.Mocked<PluginCacheManager> = {
+    getClient: jest.fn(),
+  };
 
   let app: express.Express;
 
@@ -102,12 +107,14 @@ describe('createRouter', () => {
       config: new ConfigReader({}),
       logger: getVoidLogger(),
       discovery,
+      cache,
     });
     const recommendedRouter = await createRouter({
       publisher,
       config: new ConfigReader({}),
       logger: getVoidLogger(),
       discovery,
+      cache,
     });
 
     app = express();
@@ -119,9 +126,7 @@ describe('createRouter', () => {
   describe('GET /sync/:namespace/:kind/:name', () => {
     describe('accept application/json', () => {
       it('should return not found if entity is not found', async () => {
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(
-          undefined,
-        );
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(undefined);
 
         const response = await request(app)
           .get('/sync/default/Component/test')
@@ -131,7 +136,7 @@ describe('createRouter', () => {
       });
 
       it('should return not found if entity has no uid', async () => {
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(
           entityWithoutMetadata,
         );
 
@@ -144,7 +149,7 @@ describe('createRouter', () => {
 
       it('should not check for an update without local builder', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('external');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
 
         const response = await request(app)
           .get('/sync/default/Component/test')
@@ -155,7 +160,7 @@ describe('createRouter', () => {
 
       it('should error if missing builder', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
 
         const response = await request(app)
           .get('/recommended/sync/default/Component/test')
@@ -171,7 +176,7 @@ describe('createRouter', () => {
 
       it('should execute synchronization', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
         MockDocsSynchronizer.prototype.doSync.mockImplementation(
           async ({ responseHandler }) =>
             responseHandler.finish({ updated: true }),
@@ -194,7 +199,7 @@ describe('createRouter', () => {
 
       it('should return on updated', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
         MockDocsSynchronizer.prototype.doSync.mockImplementation(
           async ({ responseHandler }) => {
             const { log, finish } = responseHandler;
@@ -219,9 +224,7 @@ describe('createRouter', () => {
 
     describe('accept text/event-stream', () => {
       it('should return not found if entity is not found', async () => {
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(
-          undefined,
-        );
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(undefined);
 
         const response = await request(app)
           .get('/sync/default/Component/test')
@@ -232,7 +235,7 @@ describe('createRouter', () => {
       });
 
       it('should return not found if entity has no uid', async () => {
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(
           entityWithoutMetadata,
         );
 
@@ -246,7 +249,7 @@ describe('createRouter', () => {
 
       it('should not check for an update without local builder', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('external');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
 
         const response = await request(app)
           .get('/sync/default/Component/test')
@@ -265,7 +268,7 @@ data: {"updated":false}
 
       it('should error if missing builder', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
 
         const response = await request(app)
           .get('/recommended/sync/default/Component/test')
@@ -286,7 +289,7 @@ data: "Invalid configuration. 'techdocs.builder' was set to 'local' but no 'prep
 
       it('should execute synchronization', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
         MockDocsSynchronizer.prototype.doSync.mockImplementation(
           async ({ responseHandler }) =>
             responseHandler.finish({ updated: true }),
@@ -312,7 +315,7 @@ data: "Invalid configuration. 'techdocs.builder' was set to 'local' but no 'prep
 
       it('should return an event-stream', async () => {
         MockedConfigReader.prototype.getString.mockReturnValue('local');
-        MockCatalogClient.prototype.getEntityByName.mockResolvedValue(entity);
+        MockCachedEntityLoader.prototype.load.mockResolvedValue(entity);
         MockDocsSynchronizer.prototype.doSync.mockImplementation(
           async ({ responseHandler }) => {
             const { log, finish } = responseHandler;

plugins/techdocs-backend/src/service/router.ts

@@ -34,6 +34,8 @@ import { Logger } from 'winston';
 import { ScmIntegrations } from '@backstage/integration';
 import { DocsSynchronizer, DocsSynchronizerSyncOpts } from './DocsSynchronizer';
 import { createCacheMiddleware, TechDocsCache } from '../cache';
+import { CachedEntityLoader } from './CachedEntityLoader';
+import { IdentityClient } from '@backstage/plugin-auth-backend';
 
 /**
  * All of the required dependencies for running TechDocs in the "out-of-the-box"
@@ -47,7 +49,7 @@ type OutOfTheBoxDeploymentOptions = {
   discovery: PluginEndpointDiscovery;
   database?: Knex; // TODO: Make database required when we're implementing database stuff.
   config: Config;
-  cache?: PluginCacheManager;
+  cache: PluginCacheManager;
 };
 
 /**
@@ -59,7 +61,7 @@ type RecommendedDeploymentOptions = {
   logger: Logger;
   discovery: PluginEndpointDiscovery;
   config: Config;
-  cache?: PluginCacheManager;
+  cache: PluginCacheManager;
 };
 
 /**
@@ -85,11 +87,23 @@ export async function createRouter(
   const router = Router();
   const { publisher, config, logger, discovery } = options;
   const catalogClient = new CatalogClient({ discoveryApi: discovery });
+  const identity = new IdentityClient({
+    discovery,
+    issuer: await discovery.getBaseUrl('auth'),
+  });
+
+  // Entities are cached to optimize the /static/docs request path, which can be called many times
+  // when loading a single techdocs page.
+  const entityLoader = new CachedEntityLoader({
+    catalog: catalogClient,
+    cache: options.cache.getClient(),
+    identity,
+  });
 
   // Set up a cache client if configured.
   let cache: TechDocsCache | undefined;
   const defaultTtl = config.getOptionalNumber('techdocs.cache.ttl');
-  if (options.cache && defaultTtl) {
+  if (defaultTtl) {
     const cacheClient = options.cache.getClient({ defaultTtl });
     cache = TechDocsCache.fromConfig(config, { cache: cacheClient, logger });
   }
@@ -109,7 +123,7 @@ export async function createRouter(
     const token = getBearerToken(req.headers.authorization);
 
     // Verify that the related entity exists and the current user has permission to view it.
-    const entity = await catalogClient.getEntityByName(entityName, { token });
+    const entity = await entityLoader.load(entityName, token);
 
     if (!entity) {
       throw new NotFoundError(
@@ -141,7 +155,7 @@ export async function createRouter(
     const entityName = { kind, namespace, name };
     const token = getBearerToken(req.headers.authorization);
 
-    const entity = await catalogClient.getEntityByName(entityName, { token });
+    const entity = await entityLoader.load(entityName, token);
 
     if (!entity) {
       throw new NotFoundError(
@@ -173,10 +187,7 @@ export async function createRouter(
     const { kind, namespace, name } = req.params;
     const token = getBearerToken(req.headers.authorization);
 
-    const entity = await catalogClient.getEntityByName(
-      { kind, namespace, name },
-      { token },
-    );
+    const entity = await entityLoader.load({ kind, namespace, name }, token);
 
     if (!entity?.metadata?.uid) {
       throw new NotFoundError('Entity metadata UID missing');
@@ -237,7 +248,7 @@ export async function createRouter(
     const entityName = { kind, namespace, name };
     const token = getBearerToken(req.headers.authorization);
 
-    const entity = await catalogClient.getEntityByName(entityName, { token });
+    const entity = await entityLoader.load(entityName, token);
 
     if (!entity) {
       throw new NotFoundError(

plugins/techdocs-backend/src/service/standaloneServer.ts

@@ -15,6 +15,7 @@
  */
 
 import {
+  CacheManager,
   createServiceBuilder,
   DockerContainerRunner,
   SingleHostDiscovery,
@@ -78,6 +79,8 @@ export async function startStandaloneServer(
 
   const publisher = await Publisher.fromConfig(config, { logger, discovery });
 
+  const cache = CacheManager.fromConfig(config).forPlugin('techdocs');
+
   logger.debug('Starting application server...');
   const router = await createRouter({
     preparers,
@@ -86,6 +89,7 @@ export async function startStandaloneServer(
     publisher,
     config,
     discovery,
+    cache,
   });
   let service = createServiceBuilder(module)
     .setPort(options.port)