backend-app-api: move healthchecks to healthService

Signed-off-by: Vincenzo Scamporlino <vincenzos@spotify.com>
2024-05-17 15:17:26 +02:00
parent 53ced701dd
commit 8d4735767d
11 changed files with 206 additions and 7 deletions
@@ -0,0 +1,81 @@
+/*
+ * 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 { mockServices } from '@backstage/backend-test-utils';
+import request from 'supertest';
+import { createHealthRouter } from './createHealthRouter';
+import express from 'express';
+
+describe('createHealthRouter', () => {
+  describe('readiness', () => {
+    it(`should return a 500 response if the server hasn't started yet`, async () => {
+      const hc = createHealthRouter({
+        lifecycle: mockServices.rootLifecycle.mock(),
+      });
+      const app = express().use(hc);
+
+      const response = await request(app).get('/v1/readiness');
+      expect(response.status).toBe(500);
+    });
+
+    it('should return 200 if the server has started', async () => {
+      const lifecycle = mockServices.rootLifecycle.mock();
+      let mockServerStartedFn = () => {};
+      lifecycle.addStartupHook.mockImplementation(
+        fn => (mockServerStartedFn = fn),
+      );
+
+      const hc = createHealthRouter({ lifecycle });
+      const app = express().use(hc);
+
+      mockServerStartedFn();
+      const response = await request(app).get('/v1/readiness').expect(200);
+      expect(response.body).toEqual({ status: 'ok' });
+    });
+
+    it(`should return a 500 response if the server has stopped`, async () => {
+      const lifecycle = mockServices.rootLifecycle.mock();
+      let mockServerStartedFn = () => {};
+      let mockServerStoppedFn = () => {};
+      lifecycle.addStartupHook.mockImplementation(
+        fn => (mockServerStartedFn = fn),
+      );
+      lifecycle.addShutdownHook.mockImplementation(
+        fn => (mockServerStoppedFn = fn),
+      );
+
+      const hc = createHealthRouter({ lifecycle });
+      const app = express().use(hc);
+
+      mockServerStartedFn();
+      mockServerStoppedFn();
+      const response = await request(app).get('/v1/readiness');
+      expect(response.status).toBe(500);
+    });
+  });
+
+  describe('liveness', () => {
+    it('should return 200 if the server has started', async () => {
+      const lifecycle = mockServices.rootLifecycle.mock();
+
+      const hc = createHealthRouter({ lifecycle });
+      const app = express().use(hc);
+
+      const response = await request(app).get('/v1/liveness').expect(200);
+      expect(response.body).toEqual({ status: 'ok' });
+    });
+  });
+});
@@ -0,0 +1,46 @@
+/*
+ * 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 Router from 'express-promise-router';
+import { Request, Response } from 'express';
+import { RootLifecycleService } from '@backstage/backend-plugin-api';
+
+export function createHealthRouter(options: {
+  lifecycle: RootLifecycleService;
+}) {
+  const router = Router();
+
+  let isRunning = false;
+  options.lifecycle.addStartupHook(() => {
+    isRunning = true;
+  });
+  options.lifecycle.addShutdownHook(() => {
+    isRunning = false;
+  });
+
+  router.get('/v1/readiness', async (_request: Request, response: Response) => {
+    if (!isRunning) {
+      throw new Error('Backend has not started yet');
+    }
+    response.json({ status: 'ok' });
+  });
+
+  router.get('/v1/liveness', async (_request: Request, response: Response) => {
+    response.json({ status: 'ok' });
+  });
+
+  return router;
+}
@@ -0,0 +1,34 @@
+/*
+ * 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 {
+  coreServices,
+  createServiceFactory,
+} from '@backstage/backend-plugin-api';
+import { createHealthRouter } from './createHealthRouter';
+
+export const healthServiceFactory = createServiceFactory({
+  service: coreServices.health,
+  deps: {
+    rootHttpRouter: coreServices.rootHttpRouter,
+    lifecycle: coreServices.rootLifecycle,
+  },
+  async factory({ lifecycle, rootHttpRouter }) {
+    rootHttpRouter.use('.backstage/health', createHealthRouter({ lifecycle }));
+
+    return {};
+  },
+});
@@ -0,0 +1,17 @@
+/*
+ * 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.
+ */
+
+export { healthServiceFactory } from './healthServiceFactory';
@@ -0,0 +1,20 @@
+/*
+ * 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.
+ */
+
+/**
+ * @public
+ */
+export interface HealthService {}
@@ -26,11 +26,6 @@ export interface HttpRouterServiceAuthPolicy {
  allow: 'unauthenticated' | 'user-cookie';
 }

-/** @public */
-export interface HttpRouterHealthCheckConfig {
-  handler: () => Promise<any>;
-}
-
 /**
 * Allows plugins to register HTTP routes.
 *
@@ -102,6 +102,13 @@ export namespace coreServices {
    import('./DiscoveryService').DiscoveryService
  >({ id: 'core.discovery' });

+  /**
+   * The service reference for the plugin scoped {@link RootHealthService}.
+   */
+  export const health = createServiceRef<
+    import('./RootHealthService').RootHealthService
+  >({ id: 'core.health', scope: 'root' });
+
  /**
   * Authentication of HTTP requests.
   *
@@ -32,10 +32,10 @@ export type {
 export type { RootConfigService } from './RootConfigService';
 export type { DatabaseService } from './DatabaseService';
 export type { DiscoveryService } from './DiscoveryService';
+export type { HealthService } from './HealthService';
 export type {
  HttpRouterService,
  HttpRouterServiceAuthPolicy,
-  HttpRouterHealthCheckConfig,
 } from './HttpRouterService';
 export type { HttpAuthService } from './HttpAuthService';
 export type {
@@ -348,7 +348,6 @@ export namespace mockServices {
    export const factory = httpRouterServiceFactory;
    export const mock = simpleMock(coreServices.httpRouter, () => ({
      use: jest.fn(),
-      healthCheckConfig: jest.fn(),
      addAuthPolicy: jest.fn(),
    }));
  }