Add an extension point for credentials resolution

backstage#1244

workspaces/copilot/plugins/copilot-backend/src/client/GithubClient.ts

@@ -15,10 +15,12 @@
  */
 
 import { ResponseError } from '@backstage/errors';
-import { Config } from '@backstage/config';
 import { Metric } from '@backstage-community/plugin-copilot-common';
 import fetch from 'node-fetch';
-import { getGithubInfo, GithubInfo } from '../utils/GithubUtils';
+import {
+  CopilotCredentialsProvider,
+  GithubInfo,
+} from '../utils/CopilotCredentialsProvider';
 
 interface GithubApi {
   getCopilotUsageDataForEnterprise: () => Promise<Metric[]>;
@@ -27,8 +29,8 @@ interface GithubApi {
 export class GithubClient implements GithubApi {
   constructor(private readonly props: GithubInfo) {}
 
-  static async fromConfig(config: Config) {
-    const info = await getGithubInfo(config);
+  static async fromConfig(credentialsProvider: CopilotCredentialsProvider) {
+    const info = await credentialsProvider.getCredentials();
     return new GithubClient(info);
   }
 

workspaces/copilot/plugins/copilot-backend/src/index.ts

@@ -21,4 +21,8 @@
  */
 
 export * from './service/router';
-export { copilotPlugin as default } from './plugin';
+export { copilotPlugin as default, copilotExtensionPoint } from './plugin';
+export {
+  type CopilotCredentialsProvider,
+  type GithubInfo,
+} from './utils/CopilotCredentialsProvider';

workspaces/copilot/plugins/copilot-backend/src/plugin.ts

@@ -16,8 +16,22 @@
 import {
   coreServices,
   createBackendPlugin,
+  createExtensionPoint,
 } from '@backstage/backend-plugin-api';
 import { createRouterFromConfig } from './service/router';
+import {
+  CopilotCredentialsProvider,
+  DefaultCopilotCredentialsProvider,
+} from './utils/CopilotCredentialsProvider';
+
+export interface CopilotExtensionPoint {
+  useCredentialsProvider(provider: CopilotCredentialsProvider): void;
+}
+
+export const copilotExtensionPoint =
+  createExtensionPoint<CopilotExtensionPoint>({
+    id: 'copliot.credentials',
+  });
 
 /**
  * Backend plugin for Copilot.
@@ -27,6 +41,13 @@ import { createRouterFromConfig } from './service/router';
 export const copilotPlugin = createBackendPlugin({
   pluginId: 'copilot',
   register(env) {
+    let credentialsProvider: CopilotCredentialsProvider;
+    env.registerExtensionPoint(copilotExtensionPoint, {
+      useCredentialsProvider(provider: CopilotCredentialsProvider) {
+        credentialsProvider = provider;
+      },
+    });
+
     env.registerInit({
       deps: {
         httpRouter: coreServices.httpRouter,
@@ -42,6 +63,9 @@ export const copilotPlugin = createBackendPlugin({
             database,
             scheduler,
             config,
+            credentialsProvider:
+              credentialsProvider ??
+              new DefaultCopilotCredentialsProvider({ config }),
           }),
         );
         httpRouter.addAuthPolicy({

workspaces/copilot/plugins/copilot-backend/src/service/router.ts

@@ -29,6 +29,7 @@ import { DatabaseHandler } from '../db/DatabaseHandler';
 import Scheduler from '../task/Scheduler';
 import { GithubClient } from '../client/GithubClient';
 import { DateTime } from 'luxon';
+import { CopilotCredentialsProvider } from '../utils/CopilotCredentialsProvider';
 
 /**
  * Options for configuring the Copilot plugin.
@@ -67,6 +68,11 @@ export interface RouterOptions {
    * Configuration for the router.
    */
   config: Config;
+
+  /**
+   * Credentials provider for the router.
+   */
+  credentialsProvider: CopilotCredentialsProvider;
 }
 
 const defaultSchedule: SchedulerServiceTaskScheduleDefinition = {
@@ -106,11 +112,12 @@ async function createRouter(
   routerOptions: RouterOptions,
   pluginOptions: PluginOptions,
 ): Promise<express.Router> {
-  const { logger, database, scheduler, config } = routerOptions;
+  const { logger, database, scheduler, config, credentialsProvider } =
+    routerOptions;
   const { schedule } = pluginOptions;
 
   const db = await DatabaseHandler.create({ database });
-  const api = await GithubClient.fromConfig(config);
+  const api = await GithubClient.fromConfig(credentialsProvider);
 
   await scheduler.scheduleTask({
     id: 'copilot-metrics',

workspaces/copilot/plugins/copilot-backend/src/utils/CopilotCredentialsProvider.ts

@@ -0,0 +1,88 @@
+/*
+ * 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 { Config } from '@backstage/config';
+import {
+  DefaultGithubCredentialsProvider,
+  GithubCredentials,
+  ScmIntegrations,
+} from '@backstage/integration';
+
+export type GithubInfo = {
+  credentials: GithubCredentials;
+  apiBaseUrl: string;
+  enterprise: string;
+};
+
+export interface CopilotCredentialsProvider {
+  getCredentials(): Promise<GithubInfo>;
+}
+
+export class DefaultCopilotCredentialsProvider
+  implements CopilotCredentialsProvider
+{
+  private readonly host: string;
+  private readonly enterprise: string;
+  private readonly integrations: ScmIntegrations;
+  private readonly credentialsProvider: DefaultGithubCredentialsProvider;
+
+  constructor(options: { config: Config }) {
+    const { config } = options;
+
+    this.integrations = ScmIntegrations.fromConfig(config);
+    this.credentialsProvider =
+      DefaultGithubCredentialsProvider.fromIntegrations(this.integrations);
+
+    this.host = config.getString('copilot.host');
+    this.enterprise = config.getString('copilot.enterprise');
+
+    if (!this.host) {
+      throw new Error('The host configuration is missing from the config.');
+    }
+
+    if (!this.enterprise) {
+      throw new Error(
+        'The enterprise configuration is missing from the config.',
+      );
+    }
+  }
+
+  async getCredentials(): Promise<GithubInfo> {
+    const githubConfig = this.integrations.github.byHost(this.host)?.config;
+
+    if (!githubConfig) {
+      throw new Error(
+        `GitHub configuration for host "${this.host}" is missing or incomplete.`,
+      );
+    }
+
+    const apiBaseUrl = githubConfig.apiBaseUrl ?? 'https://api.github.com';
+
+    const credentials = await this.credentialsProvider.getCredentials({
+      url: apiBaseUrl,
+    });
+
+    if (!credentials.headers) {
+      throw new Error('Failed to retrieve credentials headers.');
+    }
+
+    return {
+      apiBaseUrl,
+      credentials,
+      enterprise: this.enterprise,
+    };
+  }
+}