refactor: extract a create cookie middleware

Signed-off-by: Camila Belo <camilaibs@gmail.com>

plugins/auth-node/src/identity/createCookieAuthRefreshMiddleware.ts

@@ -0,0 +1,37 @@
+/*
+ * 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 { HttpAuthService } from '@backstage/backend-plugin-api';
+import { Router } from 'express';
+
+/**
+ * @public
+ * Creates a middleware that can be used to refresh the cookie for the user.
+ */
+export function createCookieAuthRefreshMiddleware(options: {
+  httpAuth: HttpAuthService;
+}) {
+  const { httpAuth } = options;
+  const router = Router();
+
+  // Endpoint that sets the cookie for the user
+  router.get('/.backstage/v1-cookie', async (_, res) => {
+    const { expiresAt } = await httpAuth.issueUserCookie(res);
+    res.json({ expiresAt: expiresAt.toISOString() });
+  });
+
+  return router;
+}

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

@@ -22,3 +22,4 @@ export {
 } from './DefaultIdentityClient';
 export { IdentityClient } from './IdentityClient';
 export type { IdentityApi, IdentityApiGetIdentityRequest } from './IdentityApi';
+export { createCookieAuthRefreshMiddleware } from './createCookieAuthRefreshMiddleware';