Compute cache keys from tokens instead of user entity refs

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

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

@@ -16,13 +16,7 @@
 import { CachedEntityLoader } from './CachedEntityLoader';
 import { CatalogClient } from '@backstage/catalog-client';
 import { CacheClient } from '@backstage/backend-common';
-import { ResponseError } from '@backstage/errors';
-import {
-  BackstageIdentityResponse,
-  IdentityClient,
-} from '@backstage/plugin-auth-backend';
 import { EntityName } from '@backstage/catalog-model';
-import { Response } from 'cross-fetch';
 
 describe('CachedEntityLoader', () => {
   const catalog: jest.Mocked<CatalogClient> = {
@@ -34,10 +28,6 @@ describe('CachedEntityLoader', () => {
     set: jest.fn(),
   } as any;
 
-  const identity: jest.Mocked<IdentityClient> = {
-    authenticate: jest.fn(),
-  } as any;
-
   const entityName: EntityName = {
     kind: 'component',
     namespace: 'default',
@@ -55,24 +45,13 @@ describe('CachedEntityLoader', () => {
 
   const token = 'test-token';
 
-  const identityResponse: BackstageIdentityResponse = {
-    id: '',
-    token,
-    identity: {
-      type: 'user',
-      userEntityRef: 'user:default/test-user',
-      ownershipEntityRefs: [],
-    },
-  };
-
-  const loader = new CachedEntityLoader({ catalog, cache, identity });
+  const loader = new CachedEntityLoader({ catalog, cache });
 
   afterEach(() => {
     jest.resetAllMocks();
   });
 
   it('writes entities to cache', async () => {
-    identity.authenticate.mockResolvedValue(identityResponse);
     cache.get.mockResolvedValue(undefined);
     catalog.getEntityByName.mockResolvedValue(entity);
 
@@ -80,14 +59,13 @@ describe('CachedEntityLoader', () => {
 
     expect(result).toEqual(entity);
     expect(cache.set).toBeCalledWith(
-      'catalog:component:default/test:user:default/test-user',
+      'catalog:component:default/test:test-token',
       entity,
       { ttl: 5000 },
     );
   });
 
   it('returns entities from cache', async () => {
-    identity.authenticate.mockResolvedValue(identityResponse);
     cache.get.mockResolvedValue(entity);
 
     const result = await loader.load(entityName, token);
@@ -97,7 +75,6 @@ describe('CachedEntityLoader', () => {
   });
 
   it('does not cache missing entites', async () => {
-    identity.authenticate.mockResolvedValue(identityResponse);
     cache.get.mockResolvedValue(undefined);
     catalog.getEntityByName.mockResolvedValue(undefined);
 
@@ -120,7 +97,6 @@ describe('CachedEntityLoader', () => {
   });
 
   it('calls the catalog if the cache read takes too long', async () => {
-    identity.authenticate.mockResolvedValue(identityResponse);
     cache.get.mockImplementation(
       () =>
         new Promise(resolve => {

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

@@ -20,24 +20,20 @@ import {
   EntityName,
   stringifyEntityRef,
 } from '@backstage/catalog-model';
-import { IdentityClient } from '@backstage/plugin-auth-backend';
 
 export type CachedEntityLoaderOptions = {
   catalog: CatalogClient;
   cache: CacheClient;
-  identity: IdentityClient;
 };
 
 export class CachedEntityLoader {
   private readonly catalog: CatalogClient;
   private readonly cache: CacheClient;
-  private readonly identity: IdentityClient;
   private readonly readTimeout = 1000;
 
-  constructor({ catalog, cache, identity }: CachedEntityLoaderOptions) {
+  constructor({ catalog, cache }: CachedEntityLoaderOptions) {
     this.catalog = catalog;
     this.cache = cache;
-    this.identity = identity;
   }
 
   async load(
@@ -73,12 +69,10 @@ export class CachedEntityLoader {
     entityName: EntityName,
     token: string | undefined,
   ): Promise<string> {
-    const key = ['catalog'];
-    key.push(stringifyEntityRef(entityName));
+    const key = ['catalog', stringifyEntityRef(entityName)];
 
     if (token) {
-      const response = await this.identity.authenticate(token);
-      key.push(response.identity.userEntityRef);
+      key.push(token);
     }
 
     return key.join(':');

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

@@ -35,7 +35,6 @@ 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"
@@ -87,17 +86,12 @@ 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.