permission-backend: remove manual construction of service discovery

We shouldn't be constructing a service discovery implementation inside
the router, since it removes the ability to provide a different
discovery mechanism.

Signed-off-by: Mike Lewis <mtlewis@users.noreply.github.com>

plugins/permission-backend/api-report.md

@@ -3,10 +3,10 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
-import { Config } from '@backstage/config';
 import express from 'express';
 import { Logger as Logger_2 } from 'winston';
 import { PermissionPolicy } from '@backstage/plugin-permission-node';
+import { PluginEndpointDiscovery } from '@backstage/backend-common';
 
 // Warning: (ae-missing-release-tag) "createRouter" is exported by the package, but it is missing a release tag (@alpha, @beta, @public, or @internal)
 //
@@ -18,7 +18,7 @@ export function createRouter(options: RouterOptions): Promise<express.Router>;
 // @public (undocumented)
 export interface RouterOptions {
   // (undocumented)
-  config: Config;
+  discovery: PluginEndpointDiscovery;
   // (undocumented)
   logger: Logger_2;
   // (undocumented)

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

@@ -17,7 +17,6 @@
 import express from 'express';
 import request from 'supertest';
 import { getVoidLogger } from '@backstage/backend-common';
-import { ConfigReader } from '@backstage/config';
 import {
   AuthorizeResult,
   Permission,
@@ -67,12 +66,10 @@ describe('createRouter', () => {
   beforeAll(async () => {
     const router = await createRouter({
       logger: getVoidLogger(),
-      config: new ConfigReader({
-        backend: {
-          baseUrl: 'http://localhost',
-          listen: { port: 7007 },
-        },
-      }),
+      discovery: {
+        getBaseUrl: jest.fn(),
+        getExternalBaseUrl: jest.fn(),
+      },
       policy,
     });
 

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

@@ -16,7 +16,6 @@
 
 import {
   errorHandler,
-  SingleHostDiscovery,
   PluginEndpointDiscovery,
 } from '@backstage/backend-common';
 import express, { Request, Response } from 'express';
@@ -26,7 +25,6 @@ import {
   BackstageIdentity,
   IdentityClient,
 } from '@backstage/plugin-auth-backend';
-import { Config } from '@backstage/config';
 import { ConflictError } from '@backstage/errors';
 import {
   AuthorizeResult,
@@ -39,7 +37,7 @@ import { PermissionIntegrationClient } from './PermissionIntegrationClient';
 
 export interface RouterOptions {
   logger: Logger;
-  config: Config;
+  discovery: PluginEndpointDiscovery;
   policy: PermissionPolicy;
 }
 
@@ -84,8 +82,8 @@ const handleRequest = async (
 export async function createRouter(
   options: RouterOptions,
 ): Promise<express.Router> {
-  const { config, policy } = options;
-  const discovery = SingleHostDiscovery.fromConfig(config);
+  const { policy, discovery } = options;
+
   const identity = new IdentityClient({
     discovery,
     issuer: await discovery.getExternalBaseUrl('auth'),

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

@@ -17,6 +17,7 @@
 import {
   createServiceBuilder,
   loadBackendConfig,
+  SingleHostDiscovery,
 } from '@backstage/backend-common';
 import { Server } from 'http';
 import { Logger } from 'winston';
@@ -34,10 +35,11 @@ export async function startStandaloneServer(
 ): Promise<Server> {
   const logger = options.logger.child({ service: 'permission-backend' });
   const config = await loadBackendConfig({ logger, argv: process.argv });
+  const discovery = SingleHostDiscovery.fromConfig(config);
   logger.debug('Starting application server...');
   const router = await createRouter({
     logger,
-    config,
+    discovery,
     policy: new AllowAllPermissionPolicy(),
   });