add status check router

packages/backend-common/package.json

@@ -35,6 +35,7 @@
     "compression": "^1.7.4",
     "cors": "^2.8.5",
     "express": "^4.17.1",
+    "express-promise-router": "^3.0.3",
     "helmet": "^3.22.0",
     "morgan": "^1.10.0",
     "stoppable": "^1.1.0",

packages/backend-common/src/service/createStatusCheckRouter.test.ts

@@ -0,0 +1,56 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 express from 'express';
+import * as winston from 'winston';
+import request from 'supertest';
+import { createStatusCheckRouter } from './createStatusCheckRouter';
+
+describe('createStatusCheckRouter', () => {
+  const logger = winston.createLogger();
+
+  it('gives status 200 when using default path', async () => {
+    const app = express();
+    app.use('', await createStatusCheckRouter({ logger }));
+
+    const response = await request(app).get('/healthcheck');
+
+    expect(response.status).toBe(200);
+    expect(response.text).toBe(JSON.stringify({ status: 'ok' }));
+  });
+
+  it('gives status 200 when using custom path', async () => {
+    const app = express();
+    app.use('', await createStatusCheckRouter({ logger, path: '/ready' }));
+
+    const response = await request(app).get('/ready');
+
+    expect(response.status).toBe(200);
+    expect(response.text).toBe(JSON.stringify({ status: 'ok' }));
+  });
+
+  it('gives status 500 when status check throws an error', async () => {
+    const app = express();
+    const statusCheck = () => {
+      throw Error('error!');
+    };
+    app.use('', await createStatusCheckRouter({ logger, statusCheck }));
+
+    const response = await request(app).get('/healthcheck');
+
+    expect(response.status).toBe(500);
+  });
+});

packages/backend-common/src/service/createStatusCheckRouter.ts

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { Logger } from 'winston';
+import Router from 'express-promise-router';
+import express from 'express';
+import { errorHandler, statusCheckHandler, StatusCheck } from '../middleware';
+
+export interface StatusCheckRouterOptions {
+  logger: Logger;
+  path?: string;
+  statusCheck?: StatusCheck;
+}
+
+export async function createStatusCheckRouter(
+  options: StatusCheckRouterOptions,
+): Promise<express.Router> {
+  const router = Router();
+  const { path = '/healthcheck', statusCheck } = options;
+
+  router.use(path, await statusCheckHandler({ statusCheck }));
+  router.use(errorHandler());
+
+  return router;
+}

packages/backend-common/src/service/index.ts

@@ -15,4 +15,5 @@
  */
 
 export { createServiceBuilder } from './createServiceBuilder';
+export { createStatusCheckRouter } from './createStatusCheckRouter';
 export type { ServiceBuilder } from './types';

packages/backend-common/src/service/lib/ServiceBuilderImpl.ts

@@ -17,7 +17,7 @@
 import { ConfigReader } from '@backstage/config';
 import compression from 'compression';
 import cors from 'cors';
-import express, { Router, RequestHandler } from 'express';
+import express, { Router } from 'express';
 import helmet from 'helmet';
 import { Server } from 'http';
 import stoppable from 'stoppable';
@@ -40,7 +40,7 @@ export class ServiceBuilderImpl implements ServiceBuilder {
   private host: string | undefined;
   private logger: Logger | undefined;
   private corsOptions: cors.CorsOptions | undefined;
-  private routers: [string, Router | RequestHandler][];
+  private routers: [string, Router][];
   // Reference to the module where builder is created - needed for hot module
   // reloading
   private module: NodeModule;
@@ -92,7 +92,7 @@ export class ServiceBuilderImpl implements ServiceBuilder {
     return this;
   }
 
-  addRouter(root: string, router: Router | RequestHandler): ServiceBuilder {
+  addRouter(root: string, router: Router): ServiceBuilder {
     this.routers.push([root, router]);
     return this;
   }

packages/backend/src/index.ts

@@ -25,12 +25,12 @@
 import {
   createServiceBuilder,
   getRootLogger,
-  statusCheckHandler,
   useHotMemoize,
 } from '@backstage/backend-common';
 import { ConfigReader, AppConfig } from '@backstage/config';
 import { loadConfig } from '@backstage/config-loader';
 import knex from 'knex';
+import healthcheck from './plugins/healthcheck';
 import auth from './plugins/auth';
 import catalog from './plugins/catalog';
 import identity from './plugins/identity';
@@ -63,6 +63,7 @@ async function main() {
   const configReader = ConfigReader.fromConfigs(configs);
   const createEnv = makeCreateEnv(configs);
 
+  const healthcheckEnv = useHotMemoize(module, () => createEnv('healthcheck'));
   const catalogEnv = useHotMemoize(module, () => createEnv('catalog'));
   const scaffolderEnv = useHotMemoize(module, () => createEnv('scaffolder'));
   const authEnv = useHotMemoize(module, () => createEnv('auth'));
@@ -74,7 +75,7 @@ async function main() {
 
   const service = createServiceBuilder(module)
     .loadConfig(configReader)
-    .addRouter('/healthcheck', await statusCheckHandler())
+    .addRouter('', await healthcheck(healthcheckEnv))
     .addRouter('/catalog', await catalog(catalogEnv))
     .addRouter('/rollbar', await rollbar(rollbarEnv))
     .addRouter('/scaffolder', await scaffolder(scaffolderEnv))

packages/backend/src/plugins/healthcheck.ts

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { createStatusCheckRouter } from '@backstage/backend-common';
+import { PluginEnvironment } from '../types';
+
+export default async function createRouter({ logger }: PluginEnvironment) {
+  return await createStatusCheckRouter({ logger, path: '/healthcheck' });
+}