auth-node: add providers extension point

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/auth-node/src/extensions/AuthProvidersExtensionPoint.ts

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2023 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 { createExtensionPoint } from '@backstage/backend-plugin-api';
+import { AuthProviderFactory } from '../types';
+
+/** @public */
+export interface AuthProviderRegistrationOptions {
+  providerId: string;
+  factory: AuthProviderFactory;
+}
+
+/** @public */
+export interface AuthProvidersExtensionPoint {
+  registerProvider(options: AuthProviderRegistrationOptions): void;
+}
+
+/** @public */
+export const authProvidersExtensionPoint =
+  createExtensionPoint<AuthProvidersExtensionPoint>({
+    id: 'auth.providers',
+  });

plugins/auth-node/src/extensions/index.ts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2023 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.
+ */
+
+export {
+  authProvidersExtensionPoint,
+  type AuthProviderRegistrationOptions,
+  type AuthProvidersExtensionPoint,
+} from './AuthProvidersExtensionPoint';

plugins/auth-node/src/index.ts

@@ -20,6 +20,7 @@
  * @packageDocumentation
  */
 
+export * from './extensions';
 export * from './flow';
 export * from './identity';
 export * from './oauth';